1
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Yang N, Yang S. Neglected sludge solid phase in sludge pretreatment process: Physicochemical characterization and mechanism study of its role in anaerobic degradation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173769. [PMID: 38848921 DOI: 10.1016/j.scitotenv.2024.173769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/01/2024] [Accepted: 06/02/2024] [Indexed: 06/09/2024]
Abstract
The low anaerobic digestion efficiency of the solid phase separated from pre-treated sludge indicates the need to explore other suitable resource utilization pathways for sludge solid phase. However, there is a lack of comprehensive and in-depth research on the physicochemical properties of sludge solid phase. This study comprehensively analyzes the characteristics of sludge solid phase and elucidates the mechanism of sludge solid phase in the anaerobic degradation of toxic wastewater. The results show that the surface free energy of sludge solid phase after different pre-treatments is mainly contributed by Lewis acid-base hydration free energy. The distribution of proteins on the surface of sludge solid phase plays a major role in the adhesion between sludge solid particles. Metal ions in the sludge solid phase are mainly present in the exchange state, followed by the carbonate state and the organics-bound state. The sludge solid phase obtained by sludge pH 12 + 150 °C treatment has the highest conductivity (1.36 mS/m) and capacitance (25.51 μF/g), mainly due to the presence of melanoidins in the sludge solid phase, which has similar semiquinone radicals to humic acids, thus increasing conductivity. The addition of sludge solid phase promotes an increase in cumulative methane production and rate of methane production. The sludge solid phase might play a role of an auxiliary carbon source acting as an adsorbent to buffer against toxicity inhibition and facilitate electron transfer. This study reveals the characteristics of sludge solid phase and its role in anaerobic digestion, providing theoretical guidance for finding suitable resource utilization pathways for sludge solid phase.
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Affiliation(s)
- Ning Yang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Shucheng Yang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
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2
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Ma D, Cheng S, Zhang Y, Ullah F, Ji G, Li A. Relation between hydrophilic/hydrophobic characteristics of sludge extracellular polymeric substances and sludge moisture-holding capacity in hot-pressing drying. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170233. [PMID: 38246382 DOI: 10.1016/j.scitotenv.2024.170233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/14/2024] [Accepted: 01/15/2024] [Indexed: 01/23/2024]
Abstract
Sludge poses a serious threat to the environmental health. Hot-pressing drying has been proven efficient in sludge treatment because of the reduced thermal contact resistance, rapid increase in sludge temperature, and high drying rate. Sludge extracellular polymeric substances (EPS) significantly influence moisture transfer. However, whether in hot-pressing or traditional thermal drying, the effect of EPS on sludge moisture-holding capacity is rarely reported. Thereby, this study investigated the relationship between hydrophilic/hydrophobic characteristics of EPS and sludge moisture-holding capacity at various drying time and mechanical compression using XAD resin fractionation. Thermodynamic analysis indicated that sludge moisture desorption isotherms, net isosteric heat of desorption, and differential entropy presented a downward trend with the increase in drying time and mechanical compression, suggesting reduced sludge moisture-holding capacity. EPS analysis showed that at the same drying time, applying 25 kPa mechanical compression increased sludge temperature by 16 % and protein content by 13.8 %. At the same sludge temperature, protein content rose by 7.3 % compared to the drying without mechanical compression. It was concluded that the fast rise in sludge temperature and the mechanical extrusion facilitated the destruction of sludge microbial flocs, accelerating the release of intracellular and EPS-bound moisture and contributing to the decrease in moisture-holding capacity. Besides, tryptophan protein-like substances were the major source of hydrophilic/hydrophobic organic matter, compared to polysaccharide and humic acid-like substances. The gradually reduced sludge moisture-holding capacity was divided into three stages. Below 67 °C, the moisture desorption was dominated by the release of intracellular moisture. Below 85 °C, the increase in protein and the enhanced exposure of hydrophobic functional groups in protein improved the hydrophobicity of EPS. Above 85 °C, protein consumption due to thermal decomposition and browning reaction facilitated the desorption of EPS-bound moisture. Hence, this study provided novel insights into the mechanism of sludge drying.
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Affiliation(s)
- Dexiao Ma
- School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024 Liaoning, China
| | - Shuo Cheng
- School of Environment and Society, Tokyo Institute of Technology, 2-12-1 S6-10 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Yulin Zhang
- School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024 Liaoning, China
| | - Fahim Ullah
- School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024 Liaoning, China
| | - Guozhao Ji
- School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024 Liaoning, China.
| | - Aimin Li
- School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024 Liaoning, China.
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3
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Yuan H, Zhu N. Progress of improving waste activated sludge dewaterability: Influence factors, conditioning technologies and implications and perspectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168605. [PMID: 37989393 DOI: 10.1016/j.scitotenv.2023.168605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/06/2023] [Accepted: 11/14/2023] [Indexed: 11/23/2023]
Abstract
Large amounts of waste activated sludge (WAS) as a by-product generated from the biological treatment in wastewater treatment plants (WWTPs) is of high moisture content (MC), organic pollutants, heavy metals and pathogenic bacteria, it may cause serious environmental ecological risk without appropriate disposal. More than one half of the total operation cost is accounted for sludge disposal in a WWTP. Dewatering is an essential and important step during the sludge treatment and disposal process for it could efficiently reduce its volume, and be beneficial to the subsequent treatment and disposal of sludge. However, sludge should be conditioned before mechanical dewatering because of its high hydrophilicity. In this work, it presented a comprehensive review on sludge dewatering including summarizing the dewaterability measurement indexes, affecting factors, conditioning technologies, the improvement mechanisms. Finally, based on the eventual disposal and low carbon emission target, the implications and perspectives development of sludge conditioning were discussed. Based on the above discussion, there is no unified theoretical insight of the improvement mechanism of sludge dewaterability. In addition, the relationship between the microstructure of organic matters in sludge floc and the dewaterability should be deepened. Especially, how to choose the optimal conditioning technology for sludge dewatering lies in the physical and chemical properties of sludge, however, the carbon emission of the conditioning and dewatering process also needs to be considered. Accordingly, green, low-cost and organic conditioning agents are the direction of future research, and the establishment of automatic operating system and real-time evaluation index system is the key challenge.
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Affiliation(s)
- Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China.
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4
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Chen R, Dai X, Dong B. Two birds with one stone: The multiple roles of hydrothermal treatment in dewatering municipal sludge and producing value-added products. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:165072. [PMID: 37364842 DOI: 10.1016/j.scitotenv.2023.165072] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 06/28/2023]
Abstract
Sludge dewatering and resource recovery are key steps in the sustainable treatment of municipal sludge (MS) owing to the high levels of moisture and nutrients. Among the treatment options available, hydrothermal treatment (HT) is promising to efficiently improve dewaterability and recover biofuels, nutrients, and materials from MS. However, hydrothermal conversion at different HT conditions generates multiple products. Integrating the characteristics of dewaterability and value-added products under different HT conditions facilitates the application of HT for the sustainable management of MS. Therefore, a comprehensive review of HT for its multiple roles in MS dewatering and value-added resource recovery is conducted. First, the impact of HT temperature on sludge dewaterability and key mechanisms are summarized. Then, this study elucidates the characteristics of biofuels produced (combustible gases, hydrochars, biocrudes, and H2-rich gases), nutrient recovery (proteins and phosphorus), and value-added materials under a wide range of HT conditions. Importantly, along with the integration and evaluation of HT product characteristics under different HT temperatures, this work proposes a conceptual sludge treatment system that integrates the different value-added products in different HT stages. Furthermore, a critical evaluation of the knowledge gaps in the HT for sludge deep dewatering, biofuels, nutrients, and materials recovery is provided along with recommendations for further research.
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Affiliation(s)
- Renjie Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, PR China.
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5
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Shao M, Zhang C, Wang X, Wang N, Chen Q, Cui G, Xu Q. Co-digestion of food waste and hydrothermal liquid digestate: Promotion effect of self-generated hydrochars. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2023; 15:100239. [PMID: 36820150 PMCID: PMC9937904 DOI: 10.1016/j.ese.2023.100239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
Hydrothermal treatment (HTT) can efficiently valorize the digestate after anaerobic digestion. However, the disposal of the HTT liquid is challenging. This paper proposes a method to recover energy through the anaerobic co-digestion of food waste and HTT liquid fraction. The effect of HTT liquid recirculation on anaerobic co-digestion performance was investigated. This study focused on the self-generated hydrochars that remained in the HTT supernatant after centrifugation. The effect of the self-generated hydrochars on the methane (CH4) yield and microbial communities were discussed. After adding HTT liquids treated at 140 and 180 °C, the maximum CH4 production increased to 309.36 and 331.61 mL per g COD, respectively. The HTT liquid exhibited a pH buffering effect and kept a favorable pH for the anaerobic co-digestion. In addition, the self-generated hydrochars with higher carbon content and large oxygen-containing functional groups remained in HTT liquid. They increased the electron transferring rate of the anaerobic co-digestion. The increased relative abundance of Methanosarcina, Syntrophomonadaceae, and Synergistota was observed with adding HTT liquid. The results of the principal component analysis indicate that the electron transferring rate constant had positive correlationships with the relative abundance of Methanosarcina, Syntrophomonadaceae, and Synergistota. This study can provide a good reference for the disposal of the HTT liquid and a novel insight regarding the mechanism for the anaerobic co-digestion.
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Xu X, Zhu D, Jian Q, Wang X, Zheng X, Xue G, Liu Y, Li X, Hassan GK. Treatment of industrial ferric sludge through a facile acid-assisted hydrothermal reaction: Focusing on dry mass reduction and hydrochar recyclability performance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161879. [PMID: 36716871 DOI: 10.1016/j.scitotenv.2023.161879] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/15/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Large amounts of Fenton sludge and waste activated sludge (WAS) are mixed as ferric sludge (FS) in most industrial wastewater treatment plants. The treatment of such waste represents a challenge and quantity-dependent cost, so that a reliable way for FS waste reduction is required. In this study, we develop a facile acid-assisted hydrothermal treatment (HT) for the cost-efficient treatment of hazardous FS waste. Sulfuric acid was dosed at 0.25 mL/g dry solid (DS) to the HT process, which significantly increased the total solid mass reduction (TMR) by 25.1 % and dry mass reduction (DMR) by 104.4 %. The participation of sulfuric acid during the HT process changed the HT reaction pathway from dehydration to demethylation based on the analysis of the derivative thermogravimetric and Van Krevelen diagram. The addition of sulfuric acid improved the release of Fe from FS by 52.9 %, which contributed to the DMR. During the acid-assisted HT, Fe(III) was effectively reduced to Fe(II) within the produced hydrochar, which can be recycled for the Fenton reaction during the degradation of actual industrial wastewater such as pharmaceutical wastewater. Moreover, Sulfuric acid facilitated the generation of sulfonated hydrochar, which was efficient as an adsorbent for the complete removal of some metals such as Cu(II) - cation metal (98.8 %) and Cr(VI) - anion metal (99.9 %). This study firstly provides a novel and reliable approach for hazardous FS reduction and pointed out the recycling of hydrochar as the supplement for the Fenton reaction and adsorbents for some hazardous heavy metals.
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Affiliation(s)
- Xianbao Xu
- College of Environmental Science and Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Daan Zhu
- College of Environmental Science and Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Qiwei Jian
- School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
| | - Xiaonuan Wang
- College of Environmental Science and Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Xiaohu Zheng
- Institute of Artificial Intelligence, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Gang Xue
- College of Environmental Science and Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Yanbiao Liu
- College of Environmental Science and Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Xiang Li
- College of Environmental Science and Engineering, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.
| | - Gamal Kamel Hassan
- Water Pollution Research Department, National Research Centre, 33El-Bohouth St. (Former El-Tahrir St.), Dokki, P.O. 12622, Giza, Egypt
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7
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Zhang X, Wang Z, Peng X, Xiao J, Wu Q, Chen X. Comprehensive evaluation of sewage sludge anaerobic digestion process with different digestate treatments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:56303-56316. [PMID: 36917383 DOI: 10.1007/s11356-023-26214-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/26/2023] [Indexed: 06/18/2023]
Abstract
Anaerobic digestion is one of the most promising methods for reducing sewage sludge and recovering energy. In the present study, a comparative life cycle assessment (LCA) of sewage sludge anaerobic digestion processes with different digestate treatments, including mesophilic anaerobic digestion with digestate landfilling (CAD-1) and digestate incineration (CAD-2), thermophilic anaerobic digestion combined with thermal hydrolysis pre-treatment with digestate land use (THPAD-1), and digestate incineration (THPAD-2), was performed to evaluate their environmental, resource, economic, and comprehensive performances using the SimaPro software. Environmental impact analysis revealed marine ecotoxicity, freshwater ecotoxicity, and human carcinogenic toxicity as the most obvious impacts, resulting in the most significant damage to human health. Resource analysis indicated that anaerobic digestion combined with cogeneration and digestate incineration is advantageous to high energy recovery, but digestate incineration is disadvantageous to economic performance because of increased investment costs. Comparison of the four processes revealed that THPAD-2 results in the largest environmental damage, whereas CAD-1 has the smallest load. Meanwhile, THPAD-2 and THPAD-1 exhibit the best resource performance and net economic benefit, respectively. The comprehensive evaluation indices revealed that THPAD-1 and CAD-2 show better comprehensive performance. And the deep drying incineration process exhibited better comprehensive performance than sewage sludge anaerobic digestion processes.
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Affiliation(s)
- Xiaoyong Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Zhenjiang Wang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Xiaowei Peng
- Shenzhen Energy Environment Co., Ltd, Shenzhen, 518000, China
| | - Jun Xiao
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China.
| | - Qijing Wu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Xiaoping Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
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8
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Wang L, Lü K, Chang Y, Cao X, Huo Q. Mesoporous carbon material prepared from sewage sludge hydrochar using Pluronic F127 as template for efficient removal of phenolic compounds: Experimental study and mechanism interpretation via advanced statistical physics model. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116841. [PMID: 36436439 DOI: 10.1016/j.jenvman.2022.116841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 06/16/2023]
Abstract
Mesoporous carbon material (MCM) with rich ether surface group was prepared from sewage sludge hydrochar using Pluronic F127 as template under pyrolysis activation, which provided an energy-efficient method to promote the resource utilization of sewage sludge as adsorbents for phenols removal from water. The MCM possessed high surface area (549 m2/g), abundant mesopores (average width 3.81 nm) and well-developed graphite structure. Acidic conditions and low temperatures favored the adsorption of phenolic compounds. The quick adsorption process of reaching over 85% of the capacity in the first 10 min and intraparticle diffusion as primary rate-limiting step were observed for all phenolic compounds. Advanced statistical physics analysis was used successfully to interpret the adsorption mechanism of phenols onto MCM and revealed a multi-molecular monolayer adsorption process primarily through negative charge-assisted hydrogen bond interaction where the ether functional group contributed to the predominant active sites. The adsorption capacity of phenolic compounds depended upon the number of molecules adsorbed per ether active site and the available density of ether bond group on the surface of MCM. 2,4,6-trichlorophenol showed a highest adsorption priority to occupy the limited ether active sites and its adsorption capacity reached 0.49 mmol/g, while p-nitrophenol exhibited a maximum number of molecules adsorbed on the single ether active site, showing an adsorption capacity of 0.42 mmol/g. The synergistic effect of multi-interactions mechanisms resulted in phenolic compounds removal with adsorption energies lower than 30 kJ/mol. This prepared MCM adsorbent is promising for application in treatment of water polluted by phenols.
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Affiliation(s)
- Liping Wang
- School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, Inner Mongolia, China.
| | - Kai Lü
- School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, Inner Mongolia, China
| | - Yuzhi Chang
- Jining Environmental Monitoring Center, Ulanqab, 012000, Inner Mongolia, China.
| | - Xinshuai Cao
- School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, Inner Mongolia, China
| | - Qing Huo
- School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, Inner Mongolia, China
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9
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Dai Z, Liu L, Duan H, Li B, Tang X, Wu X, Liu G, Zhang L. Improving sludge dewaterability by free nitrous acid and lysozyme pretreatment: Performances and mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:158648. [PMID: 36096212 DOI: 10.1016/j.scitotenv.2022.158648] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Reducing the water content of waste activated sludge (WAS) is critical for sludge treatment and disposal in wastewater treatment plants (WWTPs). In this study, a new combined conditioning processes by using lysozyme (LZM) and free nitrous acid (FNA) were proposed and demonstrated to enhance the dewaterability of WAS. The water content of sludge cake dropped from 82.82 % to 68.42 % (1 h FNA treatment + 1 h LZM treatment) and 69.52 % (6 h FNA treatment + 1 h LZM treatment) with the combined FNA and LZM treatment; and the corresponding capillary suction time (CST) reduction efficiency increased 49.29 % (1 h FNA treatment + 1 h LZM treatment) and 52.98 % (6 h FNA treatment + 1 h LZM treatment). A comprehensive investigation conducted in this study revealed the underlying mechanism of dewaterability improvement lies in the transformations of extracellular polymeric substances (EPS). The combined conditioning led to enhanced hydrophobicity in the sludge, as suggested by FTIR protein secondary structure and interfacial free energy. The reduced zeta potential and the potential barrier indicated the reduction of the repulsive force of sludge particles and the bound water content in the conditioned floc. The hydrophobicity, flow permeability and flocculability were enhanced after combined treatment, leading to the release of bound water.
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Affiliation(s)
- Ziheng Dai
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China
| | - Lei Liu
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China.
| | - Haoran Duan
- Australian Centre for Water and Environmental Biotechnology (ACWEB), The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Biqing Li
- Guangzhou sewage purification Co. Ltd., Guangzhou 510655, China
| | - Xia Tang
- Guangzhou sewage purification Co. Ltd., Guangzhou 510655, China
| | - Xuewei Wu
- Guangzhou sewage purification Co. Ltd., Guangzhou 510655, China
| | - Gang Liu
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China
| | - Liguo Zhang
- School of Environment, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, MOE Key Laboratory of Theoretical Chemistry of Environment, Guangdong Provincial Engineering Technology Research Center for Wastewater Management and Treatment, South China Normal University, Guangzhou 510006, China.
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10
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Xiao T, Zhang L, Chen S, Dai X, Dong B. A novel application of dissolved ozone flotation on sewage sludge thickening: Performance and mechanism investigation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 842:156874. [PMID: 35753468 DOI: 10.1016/j.scitotenv.2022.156874] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/31/2022] [Accepted: 06/18/2022] [Indexed: 06/15/2023]
Abstract
Sludge thickening in sewage treatment plants is an essential step to reduce the sewage sludge volume and provide space for collaborative anaerobic digestion of sludge and other urban organic wastes. Dissolved ozone flotation (DOF) is a novel choice worthy of application in the field of sludge thickening. In order to investigate the effect of DOF thickening, the total solid content (TS %) was used to characterize the thickening performance under different O3 dosage. The optimal condition was determined to be polyacrylamide (PAM) dosage = 3 ‰ TS, air floatation time = 2 h and O3 dosage = 12 mg/g TS, under which the TS % of raw-sewage sludge (RS) increased from 0.33 ± 0.01 % to 8.03 ± 0.06 %. In this study, the relationship between the sludge thickening performance, physicochemical properties, and the changes of organic matter (content, structure and molecular weight) in extracellular polymers (EPS) was systematically clarified. The results indicated that the DOF couple with PAM could change the sludge surface properties, destroy the sludge floc structure, release intracellular organic matter, and increase moisture fluidity. The surface hydrophilicity/hydrophobicity, protein (PN) secondary structure and moisture distribution were mainly responsible for sludge thickening performance. Moreover, the change of TS % during the DOF thickening process was mainly caused by the variations of the organic matter content in EMPS layer. The identification of key influencing factors was conducive to the further regulation and upgrading of the novel application for enhanced sludge thickening in sewage treatment plants.
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Affiliation(s)
- Tingting Xiao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Lingjun Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - Sisi Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Bin Dong
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, PR China.
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11
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Li Q, Cheng T, Lu Y, Zhang B, Huang Y, Yang Y, Li C, Li J, Wang H, Fu P. Sludge low-temperature drying with mainly non-phase change in mere seconds based on particle high-speed self-rotation in cyclone. WATER RESEARCH 2022; 224:119092. [PMID: 36115157 DOI: 10.1016/j.watres.2022.119092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 09/03/2022] [Accepted: 09/07/2022] [Indexed: 06/15/2023]
Abstract
Improper sludge treatment will cause serious environmental problems, and sludge drying is the key to effective treatment. Almost all the existing sludge drying technologies use heating to overcome the great latent heat of moisture vaporization, which leads to high drying energy consumption. In this study, based on the particle high-speed self-rotation in the cyclone and micro-interface oscillations, the cyclone self-rotation drying (CSRD) technology was developed. It can realize drying of the dewatered landfill sludge (DLS) and the urban sewage dewatered sludge (UDSS) with mainly non-phase change. The obtained results reveal that at low carrier gas temperatures (< 100 °C) and very short residence time (< 15 s), the moisture content of the DLS decreased from 53% to 6.85%, and that of the UDSS decreased from 67% to 18.92%. Through calculation, the proportions of moisture non-phase change removal during the CSRD process touched 68.94% and 63.39%, respectively. Based on the experimental studies, we proposed an enlarged industrial application program (50 t/d) for the UDSS drying by employing the CSRD technology. The operating cost was 159.69 CNY/t H2O, showing prominent advantages. This study can provide guidelines for the practical application of CSRD technology and fill the scientific gap in the field of moisture non-phase change separation for sludge drying.
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Affiliation(s)
- Qiqi Li
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China
| | - Tingting Cheng
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China
| | - Yufei Lu
- Shanghai Ceo Environmental Protection Technology Co. Ltd, Shanghai, 200438, China
| | - Bin Zhang
- Shanghai Ceo Environmental Protection Technology Co. Ltd, Shanghai, 200438, China
| | - Yuan Huang
- Institution of Environmental Pollution and Health, Shanghai University, Shanghai, 200444, China
| | - Yuan Yang
- Shanghai Ceo Environmental Protection Technology Co. Ltd, Shanghai, 200438, China
| | - Chunjiang Li
- Shanghai Ceo Environmental Protection Technology Co. Ltd, Shanghai, 200438, China
| | - Jianping Li
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China
| | - Hualin Wang
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China
| | - Pengbo Fu
- National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, East China University of Science and Technology, Shanghai, 200237, China.
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12
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Yu Y, Li P, Zhu B, Liu Y, Yu R, Ge S. The application of sulfate radical-based advanced oxidation processes in hydrothermal treatment of activated sludge at different stages: A comparative study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:59456-59465. [PMID: 35386076 DOI: 10.1007/s11356-022-20038-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 03/29/2022] [Indexed: 06/14/2023]
Abstract
Integrating hydrothermal treatment (HT) and advanced oxidation processes (AOP) was proved to be a promising approach for improving sludge dewaterability. In this study, the EPS valorization under elevated temperature and sulfate radical-based AOP were investigated to clarify the valorization of organic matter in different EPS layers and its effects on the sludge dewaterability. Results indicated that the organic matters in the inner layer of EPS decreased sharply with the elevated temperature, and released into the soluble EPS. Sulfate radical-based AOP significantly accelerated the degradation of organics and microbial cells lysis, especially in the presence of ZVI. The protein with the higher hydrophobicity was detected under the AOP enhanced HT. A better synergistic effect on sludge dewaterability was obtained by integrated the AOP at the initial hydrothermal stage. 3D-EEM and parallel factor analysis indicated that the protein and microbial by-product like substances in tightly bound EPS significantly affected the dewaterability.
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Affiliation(s)
- Yang Yu
- School of Energy and Environment, MOE Key Laboratory of Environmental Medicine Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
| | - Panpan Li
- School of Energy and Environment, MOE Key Laboratory of Environmental Medicine Engineering, Southeast University, Nanjing, 210096, People's Republic of China
| | - Bingxing Zhu
- School of Energy and Environment, MOE Key Laboratory of Environmental Medicine Engineering, Southeast University, Nanjing, 210096, People's Republic of China
| | - Ye Liu
- College of Science and Technology, Hebei Agricultural University, No. 289 Lingyusi Street, Baoding, 071001, Hebei, People's Republic of China
| | - Ran Yu
- School of Energy and Environment, MOE Key Laboratory of Environmental Medicine Engineering, Southeast University, Nanjing, 210096, People's Republic of China
| | - Shifu Ge
- School of Energy and Environment, MOE Key Laboratory of Environmental Medicine Engineering, Southeast University, Nanjing, 210096, People's Republic of China
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13
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Lin F, Li B. Changes of network structure and water distribution in sludge with the stratified extraction of extracellular polymeric substances. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:48648-48660. [PMID: 35195865 DOI: 10.1007/s11356-022-19075-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
The water in sludge is trapped within the extracellular polymeric substance (EPS) with gelatinous structure, greatly challenging the sludge deep dewatering. In this paper, the effect of the EPS viscoelasticity and the structural characteristics of sludge flocs on water distribution was revealed to provide a highly efficient approach in research on sludge dewatering. After biological, and physical method conditioning, the change of viscoelasticity and sludge network structure before/after EPS extraction was comprehensively explored, together with the sludge dewaterability and water distribution. The results suggested the proportion of capillary water and adsorption water carried in soluble EPS (S-EPS) was 59.17% and 40.83%, and that in tightly bound EPS (TB-EPS) was 54.77% and 45.23%, respectively. By contrast, the capillary water in loosely bound EPS (LB-EPS) accounted for as high as 99.99%. In comparison with raw sludge, adsorption water proportion in TB-EPS and S-EPS was reduced after lysozyme (LZM) or freezing-thaw conditioning, which was ascribed to reduction of EPS viscosity and the weakness of water adsorption capacity. Additionally, the sludge yield stress (τy) value first reduced and then increased with the extraction of EPS. Meanwhile, the consistency coefficient (k) also decreased from 4.23 Pa·sn to 0.006 Pa·sn and then slightly increased after LZM conditioning. This observation indicated the sludge system became sensitive to shearing, and its network structural strength as well as colloid elasticity first weakened and then slightly strengthened. In addition, after LZM or freezing-thaw conditioning, the sludge particle size significantly increased after TB-EPS extraction, while the sludge particle more easily absorbed water molecules, thereby increasing adsorption water and capillary water within the sludge flocs. This phenomenon also resulted in an increasing trend of capillary suction time (CST) after TB-EPS extraction, indicating the deterioration of sludge filtration performance.
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Affiliation(s)
- Feng Lin
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Bingyun Li
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China.
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14
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Chen R, Dai X, Dong B. Decrease the effective temperature of hydrothermal treatment for sewage sludge deep dewatering: Mechanistic of tannic acid aided. WATER RESEARCH 2022; 217:118450. [PMID: 35452974 DOI: 10.1016/j.watres.2022.118450] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/15/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
The formation of refractory compounds and high nitrogen concentrations in filtrates is the bottleneck of hydrothermal treatment (HT) for sludge deep dewatering. To simultaneously solve these two problems, tannic acid (TA)-aided HT was firstly developed in this study. TA addition improved dewaterability under all investigated HT temperatures by improving the sludge relative hydrophobicity. Moreover, the effective HT temperature was reduced from 180 to 160 ℃. The soluble extracellular polymeric substances (S-EPSs) of the sludge hydrothermally treated at 160 ℃ under the optimal TA dose (0.15 mmol/g total solids) contained 47.27% less total organic nitrogen than the S-EPSs of the raw sludge. This result means that the corresponding filtrate contained lower concentrations of refractory compounds and nitrogen than those under the conventional HT conditions and thus could be more easily treated. Furthermore, the changes in the protein secondary structure and the interaction of TA with high-molecular-weight (HMW) proteins in S-EPSs were found to be highly relevant (p < 0.05) to the improvement of sludge dewaterability. With increasing HT temperature (120-180 ℃), the S-EPS HMW proteins with numerous hydrophilic functional groups (hydroxyl and carboxyl) were hydrolyzed, and their secondary structures unfolded; consequently, more sites were exposed for hydrophobic binding with TA, and the TA-protein interaction was more stable and spontaneous. The precipitation of protein with TA also increased with the HT temperature. Thus, TA-aided HT improves protein precipitation and sludge dewaterability through protein structure destruction and the production of more hydrophobic binding sites for TA. The identification of the influencing mechanisms on SS EPS-TA interaction mode and binding capacity are conducive to the further upgrading of TA-aided HT for engineering applications.
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Affiliation(s)
- Renjie Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, PR China.
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15
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Shi Y, Chen Z, Zhu K, Fan J, Clark JH, Luo G, Zhang S. Speciation evolution and transformation mechanism of P during microwave hydrothermal process of sewage sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 815:152801. [PMID: 34986420 DOI: 10.1016/j.scitotenv.2021.152801] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Due to the global shortage of phosphate ore, sewage sludge is an important resource for P recovery. This study aims to investigate how P was migrated and transformed during the microwave hydrothermal (MHT) process of sewage sludge. The effects of MHT and hydrothermal (HT) conversion were compared. The results reveals that there were no significant differences on the P distribution and speciation changes between the HT and MHT products, especially under high hydrothermal temperature. Ortho-P/Pyro-P was the dominant P form in the hydrothermal solid products, and high temperature promoted the transformation of C-O-P to Ortho-P/Pyro-P. The analysis of X-ray absorption near edge structure (XANES) shows that Ca5(PO4)3OH was formed after the hydrothermal processes. The relative abundance of Ca-P decreased first and then increased with increasing hydrothermal temperature. Moderate MHT temperature (170 °C) and holding time (30-60 min) promoted the transformation of P to the liquid products. Generally, the effect of MHT temperature was more significant than that of heating type and holding time on the variations of P distribution and speciations.
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Affiliation(s)
- Yan Shi
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, PR China; Green Chemistry Center of Excellence, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Zheng Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, PR China
| | - Keliang Zhu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, PR China
| | - Jiajun Fan
- Green Chemistry Center of Excellence, Department of Chemistry, University of York, York YO10 5DD, UK
| | - James H Clark
- Green Chemistry Center of Excellence, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Gang Luo
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Shicheng Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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16
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Yang N, Yang S, Zheng X. Inhibition of Maillard reaction during alkaline thermal hydrolysis of sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152497. [PMID: 34968583 DOI: 10.1016/j.scitotenv.2021.152497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/03/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
The Maillard reaction (MR) occurs during the alkaline thermal hydrolysis (ATH) of sludge, which affects the quantity and quality of recovered protein. In this paper, four different sulfites were added to investigate their inhibitory effects on melanoidin production. The results showed that sulfites inhibited melanoidin production during ATH of sludge and the inhibitory rate increased with their concentration. At a concentration of 5.71 g/L, the inhibitory rates of NaHSO3 on melanoidin were 63.27%. Furthermore, the 3D-EEM (Three-Dimension Excitation-Emission-Matrix) fluorescence spectroscopy and protein testing data showed that the inhibition of melanoidin production was accompanied by an increased protein concentration, and protein increased with increasing sulfites concentration. A 2.5-fold increase in protein concentration with Na2S2O4 significantly enhanced the quantity of protein recovered. Therefore, the addition of sulfite during ATH of sludge reduces the amount of non-biodegradable melanoidin, which in turn benefits protein recovery.
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Affiliation(s)
- Ning Yang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Shucheng Yang
- Department of Environmental Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Xing Zheng
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Shaanxi 710048, China
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17
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Fang Z, Zhou Z, Xue G, Yu Y, Wang Q, Cheng B, Ge Y, Qian Y. Application of sludge biochar combined with peroxydisulfate to degrade fluoroquinolones: Efficiency, mechanisms and implication for ISCO. JOURNAL OF HAZARDOUS MATERIALS 2022; 426:128081. [PMID: 34933257 DOI: 10.1016/j.jhazmat.2021.128081] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/22/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
Peroxydisulfate (PDS) is increasingly used for in situ chemical oxidation (ISCO) of organic pollutants in groundwater, but the efficient and applicable activator is still scarce. In this study, sludge-derived biochar (SDBC) was prepared by pyrolysis to activate PDS, which could effectively degrade the fluoroquinolone antibiotics (FQs, levofloxacin, enrofloxacin, norfloxacin and ciprofloxacin). Compared with pig manure and corn straw derived biochar, SDBC showed higher efficiency in PDS activation. Singlet oxygen (1O2) was identified as the major reactive species, and the surface-bonded radicals also contributed to the FQs degradation. The selective oxidation of FQs by 1O2 was first reported, which followed the trend of enrofloxacin ~ levofloxacin > norfloxacin ~ ciprofloxacin. The CO and Fe2+ on SDBC were the dominant reactive sites for PDS activating. Products analysis revealed that FQs degradation proceeds via the cleavage of the piperazine ring, breaking of the quinolone ring, decarboxylation, and defluorination. Moreover, the tertiary amine of N (4) on enrofloxacin was more reactive towards singlet oxygen than the secondary amine of N (4) on ciprofloxacin, inducing the faster degradation and de-toxicity of enrofloxacin in the reaction system. SDBC showed high reusability in PDS activation and negligible metals leachates were detected. The column study proved the efficiency of PDS/SDBC in groundwater remediation.
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Affiliation(s)
- Zhihuang Fang
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China
| | - Zilin Zhou
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China
| | - Gang Xue
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Yang Yu
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China
| | - Qi Wang
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Biran Cheng
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China
| | - Yinglong Ge
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China
| | - Yajie Qian
- College of Environmental Science and Engineering, Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, Donghua University, Shanghai 201620, China.
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18
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Chen R, Sheng Q, Chen S, Dai X, Dong B. The three-stage effect of hydrothermal treatment on sludge physical-chemical properties: Evolution of polymeric substances and their interaction with physicochemical properties. WATER RESEARCH 2022; 211:118043. [PMID: 35026549 DOI: 10.1016/j.watres.2022.118043] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 01/02/2022] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Hydrothermal treatment (HT) is effective for the deep dewatering of sewage sludge (SS); however, the effective temperature generally exceeds 180 ℃, resulting in the production of refractory compounds in the sludge filtrates. To explore a new process based on HT, achieving ideal dehydration efficiency at lower temperatures, it is essential to identify the key sludge dewatering mechanism under different HT stages. In this study, the relationship between the properties of sludge polymeric substances (components and molecular structures) and the physical-chemical properties of sludge flocs during HT (120-260 ℃) was investigated. The results indicated that the SS surface hydrophilicity/hydrophobicity was mainly responsible for sludge dewaterability in the solubilization (120 ℃) and hydrolyzation stages (140-180 ℃), while the mechanically bound water and capillary force were the main limiting factors of sludge dewaterability during the carbonization stage (200-260 ℃). Moreover, in the solubilization stage (120 ℃), a plenty of high-Mw (Mw > 70 kDa) polymeric substances with numerous hydrophilic functional groups and a compact structure were released from the intracellular region to the outer layer, which improved the hydrophilicity of sludge floc surface and deteriorated the sludge dewaterability. With the hydrolysis of the polymeric substances (140-180 ℃, hydrolyzation stage), the destruction of proteins secondary structures and peptide chains exposed more hydrophobic groups, resulting in the release of bound water and improvement of sludge dewaterability. At HT temperatures of 200-260 ℃ (carbonization stage), dehydration and amine aldehyde condensation occurred, benefiting the formation of fixed carbon and smooth morphology structure of SS, reducing the capillary force-induced water-holding capacity of sludge flocs. The establishment of the three-stage influencing theory and the identification of key influencing factors are conducive to the further regulation and upgrading of HT.
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Affiliation(s)
- Renjie Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Qian Sheng
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Sisi Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges, Corporation, Beijing 100038, PR China.
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19
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Ebrahimi M, Dunn K, Li H, Rowlings DW, O'Hara IM, Zhang Z. Effect of hydrothermal treatment on deep dewatering of digested sludge: Further understanding the role of lignocellulosic biomass. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 810:152294. [PMID: 34906581 DOI: 10.1016/j.scitotenv.2021.152294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
In this study, lignocellulose-assisted hydrothermal treatment (HTT) of digestated sludge was studied to further understand the role of biomass in HTT and its effect on subsequent sludge dewatering. HTT of sludge-biomass mixtures at 180 °C for 60 min at a sludge/biomass total solids (TS) ratio of 1:1 led to solid residue moistures of 36%-40% after dewatering using a hydraulic press at 24 MPa, compared to 69.5% without biomass. Further investigation showed that organic acids, especially acetic acid generated from lignocellulosic biomass hydrolysed extracellular polymeric substances (EPS), especially EPS-protein, and improved sludge dewaterability. The role of organic acids was further verified with the addition of 10.0 g/L acetic acid for HTT of sludge at 180 °C in the absence of biomass. It was also observed that in HTT of sludge with 10.0 g/L acetic acid, protein nitrogen was converted to more stable forms of nitrogen such as pyrrole‑nitrogen and quaternary‑nitrogen. However, HTT with acetic acid alone resulted in dewatered solids with high ash contents, which may limit their applications as soil amendments. Combination of biomass and acetic acid with a sludge/biomass TS ratio of 3:1 and acetic acid loading of 10.0 g/L at a HTT temperature of 180 °C for 60 min led to solid moistures of 50.5% with hardwood sawdust and 57.7% with sugarcane bagasse after dewatering at 3 MPa, corresponding to total weight reductions of 66.3% and 55.7%, respectively. In contrast, HTT of sludge at 180 °C for 60 min without acetic acid and biomass resulted in a solid moisture of 76.6% after dewatering at 3 MPa and a corresponding weight reduction of 49.5%. With the use of biomass and acetic acid in HTT, the treated and dewatered solids also had increased carbon content and reduced ash content. These dewatered solids may be used as potential soil amendments though the properties related to soil applications need to be considered in future studies.
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Affiliation(s)
- Majid Ebrahimi
- Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Kameron Dunn
- Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Huan Li
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - David W Rowlings
- Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia; School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Ian M O'Hara
- Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Zhanying Zhang
- Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia.
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20
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Zhang C, Shao M, Wu H, Wang N, Wang X, Wang Q, Xu Q. Mechanism insights into hydrothermal dewatering of food waste digestate for products valorization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 804:150145. [PMID: 34517326 DOI: 10.1016/j.scitotenv.2021.150145] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 06/13/2023]
Abstract
Poor dewaterability is a bottleneck of the disposal of digestate from food waste (DFW). However, the dewatering mechanism remains unclear due to the complex composition of DFW. Understanding the dewatering mechanism, as well as the transformation of organic/inorganic matters is essential for the DFW management and valorization. In this study, the distribution, transformation, and complex interplay of organic and inorganic matters at different Hydrothermal treatment (HTT) temperatures were comprehensively analyzed to explore the hydrothermal dewatering mechanism of DFW. When HTT was conducted in the temperature range of 120-180 °C, the interstitial water was released as surface or free water because of membrane breaking and size reduction of the solid substrate. Releasing divalent cations increased the Zeta potential of the bulk solution. The weaker electrostatic repulsion between suspended particles made them easier to settle as the centrifugation cake. When the temperature of HTT was above 180 °C, polymerization and aromatization reactions took place gradually for organic matters, and the bound water was further removed. The generated humic substances were more hydrophobic than the raw material. In addition, the humic substance could combine with cationic metals, which decreased the zeta potential of the bulk solution but promoted the aggregation of nanoparticles and enhance the dewaterability of DFW.
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Affiliation(s)
- Chao Zhang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China
| | - Mingshuai Shao
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China
| | - Huanan Wu
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China
| | - Ning Wang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China
| | - Xue Wang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China
| | - Qian Wang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China
| | - Qiyong Xu
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Nanshan District, Shenzhen 518055, PR China.
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21
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Xiao Y, Raheem A, Ding L, Chen WH, Chen X, Wang F, Lin SL. Pretreatment, modification and applications of sewage sludge-derived biochar for resource recovery- A review. CHEMOSPHERE 2022; 287:131969. [PMID: 34450364 DOI: 10.1016/j.chemosphere.2021.131969] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/11/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
With the quick increase in industrialization and urbanization, a mass of sludge has been produced on the account of increased wastewater treatment facilities. Sewage sludge (SS) management has become one of the most crucial environmental problems because of the existence of various pollutants. However, SS is a carbon-rich material, which has favored novel technologies for biochar production, which can be utilized for dissimilar applications. This review systematically analyzes and summarizes the pretreatment, modification, and especially application of sewage sludge-derived biochar (SSBC), based on published literature. The comparative assessment of pretreatment technology such as pyrolysis, hydrothermal carbonization, combustion, deashing, and co-feeding is presented to appraise their appropriateness for SS resource availability and the production of SSBC. In addition, the authors summarize and analyze the current modification methods and divide them into two categories: physical properties and surface chemical modifications. The applications of SSBC as absorbent, catalyst and catalyst support, electrode materials, gas storage, soil amendment, and sold biofuel are reviewed in detail. Furthermore, the discussion about the existing problems and the direction of future efforts are presented at the end of each section to envisage SS as a promising opportunity for resources rather than a nuisance.
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Affiliation(s)
- Yao Xiao
- Institute of Clean Coal Technology, East China University of Science and Technology, 200237, Shanghai, PR China; National Engineering Research Center of CWS Gasification and Coal Chemical Industry (Shanghai), PR China
| | - Abdul Raheem
- Institute of Clean Coal Technology, East China University of Science and Technology, 200237, Shanghai, PR China; National Engineering Research Center of CWS Gasification and Coal Chemical Industry (Shanghai), PR China
| | - Lu Ding
- Institute of Clean Coal Technology, East China University of Science and Technology, 200237, Shanghai, PR China; National Engineering Research Center of CWS Gasification and Coal Chemical Industry (Shanghai), PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
| | - Wei-Hsin Chen
- Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, 701, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, 407, Taiwan; Department of Mechanical Engineering, National Chin-Yi University of Technology, Taichung, 411, Taiwan.
| | - Xueli Chen
- Institute of Clean Coal Technology, East China University of Science and Technology, 200237, Shanghai, PR China; National Engineering Research Center of CWS Gasification and Coal Chemical Industry (Shanghai), PR China
| | - Fuchen Wang
- Institute of Clean Coal Technology, East China University of Science and Technology, 200237, Shanghai, PR China; National Engineering Research Center of CWS Gasification and Coal Chemical Industry (Shanghai), PR China
| | - Sheng-Lun Lin
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, China
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22
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Zhang W, Chen J, Tang M, Wu H, Liu M, Ai J, Wang D. Citric acid chelated Fe(II) catalyzed peroxidation for simultaneously improving sludge dewaterability and antibiotic resistance genes (ARGs) removal. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.119925] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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23
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24
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Zhang W, Dong B, Dai X, Dai L. Enhancement of sludge dewaterability via the thermal hydrolysis anaerobic digestion mechanism based on moisture and organic matter interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 798:149229. [PMID: 34325135 DOI: 10.1016/j.scitotenv.2021.149229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/20/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
It is known that sludge dewaterability improves during the thermal hydrolysis process (THP); however, the effect of thermal hydrolysis and anaerobic digestion (THP-AD) on sludge dewaterability is unclear. Further, the difference between thermal hydrolysis as pre-treatment for anaerobic digestion (pre-THP-AD) and as post-treatment (post-THP-AD) is also unclear. Based on the evolution of the interaction between organic matter and moisture, the mechanism of pre-THP-AD and post-THP-AD improving the sludge dewaterability was explored. The capillary suction time values of pre-THP-AD and post-THP-AD increased by 58% and 59%, respectively, and the proportion of free moisture increased by 10.44% and 10.59%, respectively, compared with the conventional anaerobic digestion (CAD) process. The cell structure was destroyed and most organic matter was converted into dissolved form through THP, organic matter degraded during AD, the interaction between moisture and organic matter declined, and the mechanically bound moisture transformed into free moisture. Additionally, the intensity of hydrophilic functional groups, such as amide I decreased and amide II disappeared after (pre- and post-) THP-AD. The surface hydrophobicity of sludge samples was enhanced and sludge dewaterability improved. The mechanism of pre-/post-THP-AD enhanced sludge dewaterability based on the interaction between moisture and organic matter; additionally, this will provide a reference for optimised moisture-sludge separation processes and guidance for the optimisation of engineering operation parameters.
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Affiliation(s)
- Wei Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Lingling Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
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25
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Zhu K, Liu Q, Dang C, Li A, Zhang L. Valorization of hydrothermal carbonization products by anaerobic digestion: Inhibitor identification, biomethanization potential and process intensification. BIORESOURCE TECHNOLOGY 2021; 341:125752. [PMID: 34419878 DOI: 10.1016/j.biortech.2021.125752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 06/13/2023]
Abstract
Integrating hydrothermal carbonization (HTC) and anaerobic digestion for biorefinery-oriented full utilization of wet organic wastes is a promising emerging technology. The objectives of this study were to identify the potential inhibitory substances, evaluate the biomethane potential of mixed and aqueous products and explore process intensifying strategies. The results indicated that the high HTC temperature of 240 °C resulted in a significantly low methane yield of 60 ± 5 mL/g COD and a high Short chain fatty acid (SCFAs) accumulation of 4174 ± 76 mg/L. GC-MS analysis showed that the contents of inhibitory pyrazines, pyridines and ketones in aqueous fraction at 240 °C substantially increased from 13.14%, 0.4%, 0.55% at 180 °C to 23.34%, 2.89%, 5.13%, respectively. When the aqueous products obtained from 240 °C-HTC was supplemented or pretreated by carbonaceous material, the methane yields were greatly improved and increased to 1.3-fold and 1.8-fold, respectively. These finding could provide some valuable technical information for HTC based biorefinery of organic waste.
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Affiliation(s)
- Kongyun Zhu
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, PR China
| | - Qiutong Liu
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, PR China
| | - Chao Dang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, PR China
| | - Aimin Li
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, PR China
| | - Lei Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, PR China.
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26
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Ma D, Ji G, Zhang L, Wang D, Liu Q, Ullah F, Li A. Enhancement of conductive drying of sewage sludge with mechanical compression: Drying kinetics, and interfacial heat transfer behavior. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 796:148716. [PMID: 34274676 DOI: 10.1016/j.scitotenv.2021.148716] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Improving sludge drying efficiency is of tremendous importance for public health, subsequent treatment, and comprehensive utilization. The interfacial thermal resistance between sludge and hot wall greatly limits the conductive drying performance. This study employed mechanical compression to decrease the interfacial thermal resistance. The drying kinetics and interfacial heat transfer behavior were investigated at mechanical loads of 25 to 200 kPa, temperatures of 120 to 210 °C, and sludge thicknesses of 1.0 to 3.0 mm, and were compared to those in the conventional drying process without mechanical load. The increase of temperature and mechanical load and the decrease of thickness improved drying rates. The drying experienced one warm-up period and two falling rate periods. The breakthrough of interfacial vapor film was responsible for the rapid rise in drying rates initially. At the thickness of 3.0 mm, 210 °C, and 100 kPa, the effective moisture diffusivity was increased by 2.5 times, and the apparent activation energy was reduced by 34% compared to the traditional process in the first falling rate period, implying that mechanical compression facilitated moisture migration and bound water desorption. The effective moisture diffusivity in the first falling rate period was increased by 35% compared to the diffusivity in the second falling rate period because of the pressure-driven flow. The decrease in drying rates was due to the transformation from the pressure-driven flow to vapor diffusion-limited flow in the first falling rate period. Additionally, this study provided essential information on developing a new sludge treatment method and establishing the drying model.
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Affiliation(s)
- Dexiao Ma
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Guozhao Ji
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China.
| | - Lei Zhang
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Dong Wang
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Qi Liu
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Fahim Ullah
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Aimin Li
- School of Environmental Science & Technology, Dalian University of Technology, Dalian 116024, Liaoning, China.
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27
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Tan Y, Zhang R, Lu X, Niu C, Zhen G, Kumar G, Zhao Y. Mechanistic insights into promoted dewaterability, drying behaviors and methane-producing potential of waste activated sludge by Fe 2+-activated persulfate oxidation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 298:113429. [PMID: 34358941 DOI: 10.1016/j.jenvman.2021.113429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/25/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Sludge management represents a critical challenge because of complex compositions and poor dewaterability. Fe2+-activated persulfate oxidation (Fe2+/S2O82-) is an effective, and widely investigated method for enhancing sludge dewatering. However, the potential effects of Fe2+/S2O82- on sludge drying efficiency, anaerobic biodegradation behaviors and potential recycling of sludge residua are not yet well-known. In this study, a new sludge disposal route (step i: enhanced dewatering via Fe2+/S2O82-, and step ii: drying-incineration or anaerobic digestion) was proposed and appraised comprehensively. Results showed that Fe2+/S2O82- oxidation destroyed extracellular polymeric substances, lysed sludge cells and enhanced the dewaterability greatly. Capillary suction time and mechanical filtration time at 2.0/1.6 mmol-Fe2+/S2O82-/g-VS decreased by 88.0% and 79.6%, respectively. Moreover, 89.8% of micro-pollutants (e.g., methylbenzene, ethylbenzene, p-m-xylene and o-xylene) in sludge were removed. Besides, the pretreatment was able to alter sludge drying behaviors and methane-producing potential. Pretreated sludge exhibited faster drying rate and shorter lag-time for methane production. Incineration residua of dewatered sludge could be re-coupled with S2O82- as the conditioner to enhance sludge dewaterability, thereby reducing the chemical input and disposal cost. This study provides a novel, self-sustainable strategy for sludge management, reutilization and final safe disposal.
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Affiliation(s)
- Yujie Tan
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China; Shanghai Waterway Engineering Design and Consulting Co., Ltd, 200000, Shanghai, PR China
| | - Ruiliang Zhang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China; Institute of Eco-Chongming (IEC), 3663 N. Zhongshan Rd., Shanghai, 200062, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai ,200241, PR China
| | - Chengxin Niu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai ,200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai, 200092, PR China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai, 200062, China.
| | - Gopalakrishnan Kumar
- Institute of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, Box 8600 Forus, 4036, Stavanger, Norway
| | - Youcai Zhao
- The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092 ,Shanghai, PR China
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28
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Liu T, Wu C, Wang Y, Xue G, Zhang M, Liu C, Zheng Y. Enhanced Deep Utilization of Low-Organic Content Sludge by Processing Time-Extended Low-Temperature Thermal Pretreatment. ACS OMEGA 2021; 6:28946-28954. [PMID: 34746586 PMCID: PMC8567354 DOI: 10.1021/acsomega.1c04006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
Anaerobic digestion is an important way for maintaining sewage sludge stability, reduction, and resource recovery. However, the low organic content generally limits methane production. Recently, thermal hydrolysis has been widely used for sludge pretreatment to improve the anaerobic digestion efficiency. Generally, an increased temperature is preferred to enhance the solubility of organic matters in the sludge. However, high energy requirement comes with increased temperature. Application of low-temperature thermal treatment could overcome this drawback. However, the appropriate low-temperature pretreatment time is still uncertain. In this study, an extended contact time with low thermal pretreatment (90 °C) was chosen to realize a more efficient and economical digestion process of low-organic content sludge. The results demonstrated that the solubilization of proteins and carbohydrates was significantly promoted by the contact time-extended thermal hydrolysis pretreatment. The following anaerobic digestion efficiency of low-organic content sludge was also dramatically improved with the prolonged contact time. The maximum methane production could reach around 294.73 mL/gVS after 36 h of 90 °C treatment, which was 5.56 times that of the untreated groups. Additionally, based on the energy balance calculation, extending the thermal hydrolysis time resulted in a more economically feasible anaerobic digestion than increasing the temperature. The dewatering properties and the stability of the heavy metals were also reinforced, implying the advanced deep utilization of the digested low-organic content sludge. In conclusion, sludge pretreated by low-temperature thermal hydrolysis with a prolonged contact time could be more effective for low-organic content sludge treatment and disposal.
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Affiliation(s)
- Tingjiao Liu
- College
of Environmental Science and Engineering and Key Laboratory of Pollution
Control and Resource Recycling of Fujian Province, Fujian Normal University, Fuzhou 350007, China
| | - Chunshan Wu
- College
of Environmental Science and Engineering and Key Laboratory of Pollution
Control and Resource Recycling of Fujian Province, Fujian Normal University, Fuzhou 350007, China
| | - Yulan Wang
- Fuzhou
Planning and Design Research Institute Group Co., Ltd, Fuzhou 350000, China
| | - Guoyi Xue
- College
of Environmental Science and Engineering and Key Laboratory of Pollution
Control and Resource Recycling of Fujian Province, Fujian Normal University, Fuzhou 350007, China
| | - Menglu Zhang
- College
of Environmental Science and Engineering and Key Laboratory of Pollution
Control and Resource Recycling of Fujian Province, Fujian Normal University, Fuzhou 350007, China
| | - Changqing Liu
- School
of Geographical Science, Fujian Normal University, Fuzhou 350007, China
| | - Yuyi Zheng
- College
of Environmental Science and Engineering and Key Laboratory of Pollution
Control and Resource Recycling of Fujian Province, Fujian Normal University, Fuzhou 350007, China
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29
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Qiu C, Xu W, Wang Y, Yang J, Su X, Lin Z. Hydrothermal alkaline conversion of sewage sludge: optimization of process parameters and characterization of humic acid. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:57695-57705. [PMID: 34091839 DOI: 10.1007/s11356-021-14711-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/31/2021] [Indexed: 06/12/2023]
Abstract
Sewage sludge (SS) dewatering is a key step in sludge disposal, which plays an important role in reducing sludge volume, facilitating transportation and subsequent treatment. In this paper, a facile hydrothermal-alkaline treatment for SS was proposed, which can be used for sludge dewatering and humic acid (HA) recycling at the same time. Response surface methodology (RSM) was used to determine the optimal conditions, and a mathematical model was established to accurately predict the changes of sludge water content and the extraction rate of HA. Under the optimal conditions of 170 °C/42 min/0.05 (for hydrothermal temperature, hydrothermal time, and mass ratio of KOH to wet sludge, respectively), the water content decreased to 46.7% and the extraction rate of HA (with a purity of 96.2%) was 89.1%. The improvement of the dewatering performance effectively facilitates the subsequent disposal of the sludge. The hydrothermal-alkaline method not only realizes the efficient dehydration of the sludge, but also obtains HA from the sludge extract. The obtained HA has potential economic value in the fields of agriculture, biological medicine, environment, and the like.
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Affiliation(s)
- Chen Qiu
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong, 510006, People's Republic of China
- China-Singapore International Joint Research Institute, Guangzhou, 510000, People's Republic of China
| | - Wenbing Xu
- Dongjiang Environmental Company Limited, Shenzhen, Guangdong, 518057, People's Republic of China
| | - Yanjie Wang
- Dongjiang Environmental Company Limited, Shenzhen, Guangdong, 518057, People's Republic of China
| | - Jiakuan Yang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China
| | - Xintai Su
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong, 510006, People's Republic of China.
- China-Singapore International Joint Research Institute, Guangzhou, 510000, People's Republic of China.
| | - Zhang Lin
- School of Environment and Energy, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, Guangdong, 510006, People's Republic of China
- China-Singapore International Joint Research Institute, Guangzhou, 510000, People's Republic of China
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30
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Bei Li Y, Li Song J, Jing Yao Q, Xu Chen Z, Wei Y, Long Li H, Xiao Wang M, Jing Wang B, Min Zhou J. Effects of dissolved oxygen on the sludge dewaterability and extracellular polymeric substances distribution by bioleaching. CHEMOSPHERE 2021; 281:130906. [PMID: 34029968 DOI: 10.1016/j.chemosphere.2021.130906] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Bioleaching is a biological conditioning technology for sludge, which not only improves sludge dewatering performance but also removes heavy metals from sludge. As the bioleaching process is a comprehensive biological and chemical process, it is necessary to explore the effects of dissolved oxygen (DO) concentrations on bioleaching efficiency. Three bioleaching experiments with different DO concentrations (T1: 0.8-3.1 mg/L, T2: 3.1-5.5 mg/L, T3: 5.5-7.5 mg/L) were conducted for five days. The sludge dewatering efficiency was evaluated using capillary suction time (CST) and specific resistance to filtration (SRF). The relationship between sludge dewaterability and extracellular polymeric substance (EPS) fraction distribution was investigated. In the treatment with the highest DO concentration, the minimum values of SRF and CST were 4.31 × 1011 m/kg and 13.5 s, which occurred earlier than the treatment with the lower DO concentrations by approximately 24-48 h. A significant decrease (83.4-93.2%) in tightly bound EPS (TB-EPS) protein (PN) was observed in all treatments, while a positive correlation (r = 0.924, P < 0.01) was observed between SRF and PN content in TB-EPS. A relatively higher abundance of Acidithiobacillus was found with the increase in DO concentration. Additionally, other genera including Metallibacterium, Alicyclobacillus, Acidibacter, Acidocella, and Luteococcus also played important roles in EPS biodegradation. These results revealed that increasing the DO concentration could improve sludge dewatering performance and heavy metal removal by enhancing bioleaching microbial activity, the degradation of PN in TB-EPS, and sludge floc fragmentation, but only if sufficient energy sources were provided.
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Affiliation(s)
- Yun Bei Li
- School of Environment, Henan Normal University, China; Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, China; Henan Key Laboratory for Environmental Pollution Control, China.
| | - Jun Li Song
- School of Environment, Henan Normal University, China
| | - Qian Jing Yao
- School of Environment, Henan Normal University, China
| | - Ze Xu Chen
- School of Environment, Henan Normal University, China
| | - Yi Wei
- School of Environment, Henan Normal University, China
| | - Hai Long Li
- School of Environment, Henan Normal University, China
| | | | | | - Jia Min Zhou
- School of Environment, Henan Normal University, China
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31
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Yin R, Peng J, Sun J, Li C, Xia D, Shang C. Simultaneous removal of hydrogen sulfide, phosphate and emerging organic contaminants, and improvement of sludge dewaterability by oxidant dosing in sulfide-iron-laden sludge. WATER RESEARCH 2021; 203:117557. [PMID: 34418644 DOI: 10.1016/j.watres.2021.117557] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Liquid sludge often contains odorous and toxic hydrogen sulfide and high levels of FeII compounds (e.g., iron sulfides), due to the extensive use of iron salts for hydrogen sulfide control in sewers and for enhanced primary treatment and phosphate removal in wastewater treatment plants. We proposed and verified that dosing appropriate chemical oxidants in the sulfide-iron-laden sludge can be a simple and cost-effective strategy to remove hydrogen sulfide, phosphate, and emerging organic contaminants, and to improve sludge dewaterability simultaneously. Among the seven oxidants investigated, H2O2, ClO2 and NaClO2 were the more cost-effective oxidants than others to control hydrogen sulfide release from the liquid sludge. Dosing these three oxidants also improved sludge dewaterability and removed dissolved phosphate from the liquid sludge, with H2O2 performing the best. Hydrogen sulfide was removed via both direct oxidation by the dosed oxidants and indirect oxidation by the FeIII that was in-situ formed from oxidation of the FeII compounds in the sludge. The in-situ formed FeIII also precipitated/adsorbed the soluble phosphate into the solid form (FePO4). Fenton-like reactions occurred between H2O2 and the FeII compounds in the sludge, and hydroxyl radicals (HO•) were generated. HO• oxidized hydrogen sulfide, destructed refractory organic emerging contaminants and sludge extracellular polymeric compounds (EPSs), and improved the sludge dewaterability. The formation of HO• can be enhanced by hydrogen sulfide and the sludge EPSs present in the sludge through providing more available FeII for the Fenton-like reactions. This study demonstrates the importance of selecting and dosing suitable oxidants to the sulfide-iron-laden sludge with due consideration for the multiple benefits in engineering practices. The same principles may be also used in formulating a dual oxidant-iron strategy to treat sulfide-iron-laden sewage, sludge, and sediments for simultaneous abatement of various pollutants.
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Affiliation(s)
- Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jiadong Peng
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianliang Sun
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, School of Environment, South China Normal University, Guangzhou 510006, China.
| | - Chenchen Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Dehua Xia
- School of Environmental Science & Engineering, Sun Yat-sen University, Guangzhou, China
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
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32
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Xu M, Guo F, Zhang Y, Yang Z, Cao Y, Gui X, Xing Y. Effect of hydrothermal pretreatment on surface physicochemical properties of lignite and its flotation response. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.03.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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33
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Liu H, Basar IA, Nzihou A, Eskicioglu C. Hydrochar derived from municipal sludge through hydrothermal processing: A critical review on its formation, characterization, and valorization. WATER RESEARCH 2021; 199:117186. [PMID: 34010736 DOI: 10.1016/j.watres.2021.117186] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
Additional options for the sustainable treatment of municipal sludge are required due to the significant amounts of sludge, high levels of nutrients (e.g., C, N, and P), and trace constituents it contains. Hydrothermal processing of municipal sludge has recently been recognized as a promising technology to efficiently reduce waste volume, recover bioenergy, destroy organic contaminants, and eliminate pathogens. However, a considerable amount of solid residue, called hydrochar, could remain after hydrothermal treatment. This hydrochar can contain abundant amounts of energy (with a higher heating value up to 24 MJ/kg, dry basis), nutrients, and trace elements, as well as surface functional groups. The valorization of sludge-derived hydrochar can facilitate the development and application of hydrothermal technologies. This review summarizes the formation pathways from municipal sludge to hydrochar, specifically, the impact of hydrothermal conditions on reaction mechanisms and product distribution. Moreover, this study comprehensively encapsulates the described characteristics of hydrochar produced under a wide range of conditions: Yield, energy density, physicochemical properties, elemental distribution, contaminants of concern, surface functionality, and morphology. More importantly, this review compares and evaluates the current state of applications of hydrochar: Energy production, agricultural application, adsorption, heterogeneous catalysis, and nutrient recovery. Ultimately, along with the identified challenges and prospects of valorization approaches for sludge-derived hydrochar, conceptual designs of sustainable municipal sludge management are proposed.
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Affiliation(s)
- Huan Liu
- UBC Bioreactor Technology Group, School of Engineering, The University of British Columbia, Okanagan Campus, 1137 Alumni Avenue, Kelowna, British Columbia, V1V 1V7, Canada.
| | - Ibrahim Alper Basar
- UBC Bioreactor Technology Group, School of Engineering, The University of British Columbia, Okanagan Campus, 1137 Alumni Avenue, Kelowna, British Columbia, V1V 1V7, Canada.
| | - Ange Nzihou
- Université de Toulouse, IMT Mines Albi, RAPSODEE CNRS UMR-5302, Campus Jarlard, Albi, 81013 Cedex 09, France.
| | - Cigdem Eskicioglu
- UBC Bioreactor Technology Group, School of Engineering, The University of British Columbia, Okanagan Campus, 1137 Alumni Avenue, Kelowna, British Columbia, V1V 1V7, Canada.
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34
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Zhang H, Xue G, Chen H, Li X, Chen S. Revealing the heating value characteristics of sludge-based hydrochar in hydrothermal process: from perspective of hydrolysate. WATER RESEARCH 2021; 198:117170. [PMID: 33945948 DOI: 10.1016/j.watres.2021.117170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
Hydrothermal treatment (HT) is a promising method to convert sewage sludge to hydrochar biofuel. The heating value is directly correlated to the carbon content in hydrochar; however, the release of organic matter from sludge to hydrolysate and the transfer of the Maillard reaction products generated in the hydrolysate to the solid phase alter the carbon content in hydrochar. In this study, the relationship between hydrolysate and heating value of sludge-based hydrochar was presented, aiming to explain how the calorific value of hydrochar was affected by HT conditions. We adopted a direct combustion test to verify its clean combustion features. Hydrochar derived at 260 °C and residence time of 4 h (HC 260-4) exhibited the highest calorific value (HHVdaf = 26.23 MJ/kg) with an energy density of 1.43, and its fuel characteristics were similar to those of lignite. The increase in the HT temperature and residence time up to 260 °C and 4 h, respectively, was beneficial for enhancing HHVdaf. Conversely, further increase of the HT temperature to 300 °C and HT time to 6 h yielded a decrease in HHVdaf. Investigation of the underlying mechanism revealed that the protein and polysaccharide releasing from sludge to hydrolysate occurred the Maillard reaction (MR). The generated humic-like Maillard reaction product (MRP) was transferred to hydrochar, inducing an increase in the carbon content and calorific value and a decrease in the organic content of hydrolysate. As the carbohydrate content in the hydrolysate decreased, the MR was terminated, so no more MRP was transferred to hydrochar. At the same time, the protein was still continuously released at higher temperatures and longer residence times, yielding a decline in the HHVdaf. Moreover, clean energy utilization was verified from the reduced nitrogen content in hydrochar and lower CO and NOx emission of HC 260-4 in the combustion test. After the HT, increased hydrophobicity and a lower fraction of bound water improved the dewaterability, which is of great significance for applying hydrochar as biofuel. The findings of this study provided a new perspective to explain the heating value generation of hydrochar and more direct evidence to assess its clean combustion properties, with promising perspectives for practical applications.
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Affiliation(s)
- He Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; School of Environment and Architecture, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093, China
| | - Gang Xue
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai institute of pollution control and ecological security, Shanghai 200092, China
| | - Hong Chen
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China.
| | - Xiang Li
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Shanping Chen
- Shanghai Institute for Design & Research on Environmental Engineering Co., Ltd; Shanghai Environmental Sanitation Engineering Design Institute Co., Ltd
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35
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Belete YZ, Ziemann E, Gross A, Bernstein R. Facile activation of sludge-based hydrochar by Fenton oxidation for ammonium adsorption in aqueous media. CHEMOSPHERE 2021; 273:128526. [PMID: 33070979 DOI: 10.1016/j.chemosphere.2020.128526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/17/2020] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Lately, there has been a growing interest in converting low-cost biomass residuals, including wastewater sludge, into char-like materials for various applications. In this research, ammonium (NH4+) adsorption and desorption potential of hydrochar activated via Fenton oxidation were systematically investigated. Hydrochar was prepared from domestic wastewater treatment plant sludge and activated by Fenton oxidation using different H2O2 concentrations, H2O2/Fe2+ ratios, and activation times. The activated hydrochars (AHs) were characterized by ATR-FTIR, high-resolution XPS, BET specific surface area, and SEM, and their NH4+ adsorption capacity was analyzed. The NH4+ adsorption isotherms and kinetics, adsorption in the presence of competing ions (with and without humic acid), and NH4+ desorption were investigated. The results show that following hydrochar activation, the acidic groups' concentration and the BET surface area increased, but the morphology remained essentially unchanged. It was also found that the activation occurs within a few minutes when using a relatively low concentration of reagents, and without extensive post-treatment steps. The NH4+ adsorption onto AH at equilibrium fitted the Langmuir isotherm model, with a maximum adsorption capacity of 30.77 mg g-1, and the NH4+ adsorption kinetics fitted the pseudo-second-order model. NH4+ adsorption in the presence of competing ions decreased by up to 33 ± 3%. NH4+ desorption experiments demonstrated that NH4+ recovery can reach 33 ± 5% with ultrapure water and 67 ± 2% with 2 M KCl. The results of this study indicate that Fenton oxidation is a promising alternative for hydrochar activation, and can be used as an adsorbent for NH4+ remediation in wastewater treatment processes.
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Affiliation(s)
- Yonas Zeslase Belete
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker, 8499000, Israel
| | - Eric Ziemann
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker, 8499000, Israel
| | - Amit Gross
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker, 8499000, Israel.
| | - Roy Bernstein
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker, 8499000, Israel.
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Wang Q, Xu Q, Du Z, Zhang W, Wang D, Peng Y. Mechanistic insights into the effects of biopolymer conversion on macroscopic physical properties of waste activated sludge during hydrothermal treatment: Importance of the Maillard reaction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 769:144798. [PMID: 33465628 DOI: 10.1016/j.scitotenv.2020.144798] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/30/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
In this study, the molecular transformation of sludge biopolymers during hydrothermal treatment with the temperature ranging from 25 °C to 200 °C was examined and was seen to significantly affect the macrophysical properties (dewaterability and rheological property) of sludge. The results showed that the sludge dewaterability and flow ability under high shear stress deteriorated by a hydrothermal process at 25 °C to 120 °C, but the deterioration alleviated above the temperature threshold of 120 °C. The consistence of changes in sludge dewaterability and rheological property in HT process was mainly attributed to the variation in gel properties of soluble biopolymer. Two-stage changes in biopolymer transformation were identified, beginning with a solubilization stage from 25 °C to 120 °C in which a biopolymer with a gel-like network structure was released into liquid phase, creating flow resistance under high shear stress such that sludge dewaterability deteriorated. The second stage was identified as a conversion stage (120 °C-200 °C) in which proteins and polysaccharides hydrolyzed and experienced a Maillard reaction, leading to the degradation of the biopolymer network structure. The newly formed recalcitrant Maillard products showed weak flow response to high shear stress, allowing for an improvement in sludge dewaterability. The pathways of a Maillard reaction were identified via gas chromatography-mass spectrometer (GC-MS), 1H nuclear magnetic resonance spectroscopy (1H NMR) and two-dimensional correlation spectral analysis (2D-COS) of Fourier-transform infrared spectrometer (FTIR), etc. Three-dimensional excitation-emission matrix (3D-EEM) proved to be an applicable method for tracking Maillard reaction in sludge hydrothermal process due to the distinctive fluorescence characteristics of Maillard products. This study further clarifies the obscure process of sludge hydrothermal treatment and will help improve the accuracy of subsequent research.
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Affiliation(s)
- Qiandi Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Qiongying Xu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Zhengliang Du
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Weijun Zhang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China.
| | - Dongsheng Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, China
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Shi Y, Chen Z, Cao Y, Fan J, Clark JH, Luo G, Zhang S. Migration and transformation mechanism of phosphorus in waste activated sludge during anaerobic fermentation and hydrothermal conversion. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123649. [PMID: 32823030 DOI: 10.1016/j.jhazmat.2020.123649] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/25/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
This study investigated migration and transformation mechanism of P in waste activated sludge (WAS) during anaerobic fermentation (AF) process and the subsequent hydrothermal conversion (HTC) process. Control of pH during the AF processes was found to be significant, whereby the use of acidic (pH = 5.5) or alkaline conditions (pH = 9.5) facilitated the release of either apatite phosphorus (AP) or non-apatite inorganic phosphorus (NAIP) and organic phosphorus, respectively. At the same pH of 9.5, NaOH promoted the transfer of P into liquid phase, and P in the solid phase was mainly in the form of NAIP. In contrast, Ca(OH)2 enhanced the incorporation of P into the solid products, with the P mainly in the form of AP. The subsequent HTC process promoted the NAIP transferred to AP, and the bioavailability of P in the HTC solid products was decreased. The P K-edge X-ray absorption near edge structure analysis provided detailed information about the phosphates. It demonstrated that the conversion of Ca8H2PO4·6.5H2O to Ca5(PO4)3·OH was facilitated by HTC under the alkaline condition. This study sheds lights on transformation mechanism of P speciations during AF and HTC processes, which would provide fundamental information for effective utilization of P in bio-wastes.
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Affiliation(s)
- Yan Shi
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, PR China; Green Chemistry Center of Excellence, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Zheng Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, PR China
| | - Yang Cao
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, PR China
| | - Jiajun Fan
- Green Chemistry Center of Excellence, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - James H Clark
- Green Chemistry Center of Excellence, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Gang Luo
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China; Shanghai Technical Service Platformfor Pollution Control and Resource Utilization of Organic Wastes, Shanghai 200438, China.
| | - Shicheng Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China; Shanghai Technical Service Platformfor Pollution Control and Resource Utilization of Organic Wastes, Shanghai 200438, China.
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Chen K, Liu J, Huang S, Mei M, Chen S, Wang T, Li J. Evaluation of the combined effect of sodium persulfate and thermal hydrolysis on sludge dewatering performance. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:7586-7597. [PMID: 33037543 DOI: 10.1007/s11356-020-11123-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
This innovative study makes use of a thermal hydrolysis process (THP) and the conditioner sodium persulfate (SPS) to improve the dewaterability of sewage sludge. The best-operating conditions were optimized using response surface methodology (RSM): 100 mg/g of dry solids (DS) of SPS, 101 min of reaction time of THP, and a temperature of 200 °C. Distribution of extracellular polymeric substances (EPS), zeta potential, bound water, and solid characters were analyzed to reveal the mechanisms involved in the dewatering process. These results indicate that the sewage sludge after treatment (SPS combined with THP) had a superior dewaterability. The specific resistance to filtration (SRF) under the best conditions was 0.51 × 1011 m/kg, decreasing by 91.65% compared to the raw sludge (RS) (6.11 × 1011 m/kg). This mechanism could be explained as follows: (1) Aromaticity and hydrophobicity of sludge cake after SPS + THP treatment was increased; (2) sludge flocs were re-flocculated by charge neutralization, giving rise to a loose and porous structure; (3) the structure of extracellular polymeric substances and cells was destroyed, and the bound water was released. Overall, the conditioning by combination of SPS and THP is an effective mean to improve sewage sludge dewaterability. Graphical abstract.
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Affiliation(s)
- Kai Chen
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Jingxin Liu
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Simian Huang
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Meng Mei
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Si Chen
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China
| | - Teng Wang
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China.
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China.
| | - Jinping Li
- School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, China.
- Engineering Research Centre for Clean Production of Textile Dyeing and Printing, Ministry of Education, Wuhan Textile University, Wuhan, 430073, China.
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Ai J, Wang Z, Dionysiou DD, Liu M, Deng Y, Tang M, Liao G, Hu A, Zhang W. Understanding synergistic mechanisms of ferrous iron activated sulfite oxidation and organic polymer flocculation for enhancing wastewater sludge dewaterability. WATER RESEARCH 2021; 189:116652. [PMID: 33278721 DOI: 10.1016/j.watres.2020.116652] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/01/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The bound water in waste activated sludge (WAS) is trapped in extracellular polymeric substances (EPS) in the form of gel-like structure, leading to a great challenge in the sludge deep dewatering. Traditional flocculation conditioning is unable to destroy EPS and ineffective to remove the bound water in WAS. In this study, we employed integration of Fe(II)-sulfite oxidation and polyacrylamide flocculation (F/S-PAM) treatment for removing the bound water and improving sludge dewaterability under aerobic conditions. Meanwhile, the floc microstructure and EPS properties were examined to understand the mechanisms of F/S-PAM conditioning. F/S produced SO3·- radicals which could decompose the EPS in sludge, releasing bound water into free water. In addition, the formed Fe(III) from F/S led to re-coagulation of decomposed EPS, and C=O groups of tryptophan played the leading role in Fe-EPS association binding, causing transformation of the secondary structure of proteins (especially β-sheets and α-helices). Then, the introduction of PAM caused re-flocculation of disintegrated sludge flocs, enhancing the sludge filterability. This work provides a novel and cost-effective method for efficient removal of bound water in sludge, and subsequence improvement in sludge dewaterability.
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Affiliation(s)
- Jing Ai
- Faculty Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, Hubei, China; Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, OH 45221-0012, USA
| | - Zhiyue Wang
- The Biotechnology Institute, University of Minnesota, St. Paul, MN 55108-6106, USA
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, OH 45221-0012, USA.
| | - Ming Liu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Yun Deng
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Mingyue Tang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Guiying Liao
- Faculty Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Aibin Hu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China
| | - Weijun Zhang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China.
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40
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Chen YD, Wang R, Duan X, Wang S, Ren NQ, Ho SH. Production, properties, and catalytic applications of sludge derived biochar for environmental remediation. WATER RESEARCH 2020; 187:116390. [PMID: 32950796 DOI: 10.1016/j.watres.2020.116390] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 08/31/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
Environment-friendly and cost-effective disposal and reutilization of sludge wastes are essential in wastewater treatment processes (WWTPs). Converting activated sludge into biochar via thermochemical treatment is a promising technology for waste management in WWTPs. This review summarizes the compositions of sludge, the dewatering methods, and the thermochemical methods whichinfluence the structures, chemistry, and catalytic performances of the derived biochar. Moreover, the physiochemical characteristics and chemical stability of sludge biochar are discussed. Catalytic applications of biochar are highlighted, including the reaction mechanisms and feasibility for catalytic removal of organic contaminants. High-temperature carbonized sludge biochar exhibits excellent performance for persulfate activation in advanced oxidation processes due to the graphitic carbon structure, newly-created active sites, and fine-tuned metal species. Therefore, the sludge biochar can be produced via cost-effective and eco-friendly approaches to immobilize harmful components from sludge and remediate organic pollution in wastewater, offering a sustainable route toward sludge reutilization into value-added products for water purification.
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Affiliation(s)
- Yi-di Chen
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Rupeng Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Xiaoguang Duan
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia.
| | - Shaobin Wang
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Nan-Qi Ren
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, Guangdong 518055, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shih-Hsin Ho
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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41
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Xu D, Han X, Chen H, Yuan R, Wang F, Zhou B. New insights into impact of thermal hydrolysis pretreatment temperature and time on sewage sludge: Structure and composition of sewage sludge from sewage treatment plant. ENVIRONMENTAL RESEARCH 2020; 191:110122. [PMID: 32835676 DOI: 10.1016/j.envres.2020.110122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
This work investigated the effects of THP temperature (140-200 °C) and time (10-60 min) on the surface morphology, pyrolysis properties, and soluble compounds of dewatered sludge. Results indicate that higher temperature and longer pretreatment time considerably improve organics hydrolysis (the SCOD content increased 1.4-2.46 times, increasing 2.46 times at 200 °C). In addition, high temperature also improved the sludge pyrolysis efficiency (the highest at 200 °C), and reduced the harmful gas release, especially HCN. Moreover, the surface morphology of the sludge changed, the gap and floccules on the surface of the sludge increased. The carbohydrate content increased the highest; approximately 91.9% at 170 °C. THP promoted the decomposition of the nitrogen compounds in the sludge and facilitated their transition to a liquid phase. The total nitrogen and ammonia nitrogen content doubled, and the organic nitrogen content decreased by 50% with time increased from 10 to 60 min.
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Affiliation(s)
- Dan Xu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Xiaomin Han
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Huilun Chen
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Rongfang Yuan
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Fei Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Beihai Zhou
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
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Volatile Fatty Acids and Biomethane Recovery from Thickened Waste Activated Sludge: Hydrothermal Pretreatment’s Retention Time Impact. Processes (Basel) 2020. [DOI: 10.3390/pr8121580] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The main objective of this study was to evaluate the hydrothermal pretreatment’s retention time influence on the volatile fatty acids and biomethane production from thickened waste activated sludge under mesophilic conditions. Six different retention times of 10, 20, 30, 40, 50, and 60 min were investigated while the hydrothermal pretreatment temperature was kept at 170 °C. The results showed that the chemical oxygen demand (COD) solubilization increased by increasing the hydrothermal pretreatment retention time up to 30 min and stabilized afterwards. The highest COD solubilization of 48% was observed for the sample pretreated at 170 °C for 30 min. Similarly, the sample pretreated at 170 °C for 30 min demonstrated the highest volatile fatty acids yield of 14.5 g COD/Lsubstrate added and a methane yield of 225 mL CH4/g TCODadded compared to 4.3 g COD/Lsubstrate added and 163 mL CH4/g TCODadded for the raw sample, respectively. The outcome of this study revealed that the optimum conditions for solubilization are not necessarily associated with the best fermentation and/or digestion performance.
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Niinipuu M, Latham KG, Jansson S. The influence of inorganic components and carbon-oxygen surface functionalities in activated hydrothermally carbonized waste materials for water treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:38072-38083. [PMID: 32621190 PMCID: PMC7496029 DOI: 10.1007/s11356-020-09839-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
In this study, we have examined how the activation of hydrothermally carbonized sewage sludge and horse manure influences the inorganic component of these materials and surface chemistry. This was examined through statistical correlations between kinetic tests using trimethoprim, fluconazole, perfluorooctanoic acid, and copper, zinc, and arsenic and physicochemical properties. Yield and inorganic content varied considerably, with potassium hydroxide-activated materials producing lower yields with higher inorganic content. Phosphoric acid activation incorporated inorganically bound phosphorus into the material, although this showed no statistically relevant benefit. A maximum surface area of 1363 m2g-1 and 343 m2g-1 was achieved for the horse manure and sewage sludge. Statistical analysis found positive correlations between carbon-oxygen functionalities and trimethoprim, fluconazole, perfluorooctanoic acid, and copper removal, while inorganic content was negatively correlated. Conversely, arsenic removal was positively correlated with inorganic content. This research provides insight into the interactions with the organic/inorganic fraction of activated waste materials for water treatment.
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Affiliation(s)
- Mirva Niinipuu
- Department of Chemistry, Umeå University, Linnaeus väg 6, 90736, SE-90187, Umeå, Sweden
- Industrial Doctoral School, Umeå University, SE-90187, Umeå, Sweden
| | - Kenneth G Latham
- Department of Chemistry, Umeå University, Linnaeus väg 6, 90736, SE-90187, Umeå, Sweden
| | - Stina Jansson
- Department of Chemistry, Umeå University, Linnaeus väg 6, 90736, SE-90187, Umeå, Sweden.
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Kim HJ, Chon K, Lee YG, Kim YK, Jang A. Enhanced mechanical deep dewatering of dewatered sludge by a thermal hydrolysis pre-treatment: Effects of temperature and retention time. ENVIRONMENTAL RESEARCH 2020; 188:109746. [PMID: 32540570 DOI: 10.1016/j.envres.2020.109746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/27/2020] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
This study investigated effects of the thermal hydrolysis pre-treatment on mechanical deep dewaterability of dewatered sludge to extend understanding of dewatering characteristics of thermally hydrolyzed sludge. Floc sizes of dewatered sludge were gradually reduced during the thermal hydrolysis pre-treatment at 170 °C and 185 °C with increasing retention time whereas longer retention time (>60 min) increased floc sizes of thermally hydrolyzed sludges at 200 °C due to formation of undesired refractory organic materials (ROMs), which might hinder the disintegration of dewatered sludge flocs. Similar trends were found for thermal hydrolytic solubilization of dewatered sludge. This demonstrated that the efficiency of the thermal hydrolysis pre-treatment at a higher temperature (200 °C) with longer retention time (≥60 min) could be strongly influenced by the formation of ROMs associated with changes of solid fractions and some free amino acids (i.e., β-aminobutyric acid, 4-hydroxyproline, and cysteine). Since the trade-off between the degradation of dewatered sludge and the formation of ROMs determined mechanical deep dewaterability of thermally hydrolyzed sludge, the lowest residual weight and moisture content were observed for thermally hydrolyzed sludges at 200 °C with retention time range of 60 min (residual weight = 0.165; moisture content = 55.38%) to 90 min (residual weight = 0.160; moisture content = 59.87%). These observations were intimately correlated to variations of extracellular polymeric substances during the thermal hydrolysis pre-treatment, but not in accordance with the change pattern of capillary suction time (CST) values. This is evident that the CST value was inadequate to estimate mechanical deep dewaterability of thermally hydrolyzed sludge.
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Affiliation(s)
- Hee-Joong Kim
- Hansu Technical Service Research Center, 145 Yatap-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, Republic of Korea; Graduate School of Water Resources, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea
| | - Kangmin Chon
- Department of Environmental Engineering, College of Engineering, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, Republic of Korea.
| | - Yong-Gu Lee
- Department of Environmental Engineering, College of Engineering, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, Republic of Korea
| | - Youn-Kwon Kim
- K-water Institute, Yuseong-daero, 1689 Beon-gil, Yuseong-gu, Daejeon, Republic of Korea
| | - Am Jang
- Graduate School of Water Resources, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do, 16419, Republic of Korea.
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45
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Wei L, Xia X, Zhu F, Li Q, Xue M, Li J, Sun B, Jiang J, Zhao Q. Dewatering efficiency of sewage sludge during Fe 2+-activated persulfate oxidation: Effect of hydrophobic/hydrophilic properties of sludge EPS. WATER RESEARCH 2020; 181:115903. [PMID: 32504907 DOI: 10.1016/j.watres.2020.115903] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/13/2020] [Accepted: 04/30/2020] [Indexed: 06/11/2023]
Abstract
To clarify the effect of the hydrophobic/hydrophilic polarity of extracellular polymeric substances (EPS) on sludge filterability improvement during S2O82-/Fe2+ oxidation, waste activated sludge (WAS), glucose-fed hydrophilic sludge (HPI-WAS), and sodium acetate-fed hydrophobic sludge (HPO-WAS) samples were cultivated, and their dewatering behaviors were individually explored. Experimental results showed that S2O82- oxidation effectively disintegrated the polymeric EPS and led to a more significant reduction in the water content for HPO-WAS than for HPI-WAS (12.87-15.23% vs 9.31-12.12%), especially regarding the bound water (Wb) content. After oxidation, as high as 38.88-42.61% of the Wb within HPO-WAS samples were declined, much higher than the HPI-WAS samples (19.27-29.20%). Specifically, carbohydrates within sludge EPS negatively influenced the dewatering process of S2O82-/Fe2+ oxidation. By contrast, abundant existence of humic acids and polymeric proteinaceous components (especially those hydrophilic proteins and transitional humic acids) within the sludge EPS exhibited a converse trend. FT-IR and EEM spectral, as well as particle sizes variation for the sludge samples before and after S2O82-/Fe2+ oxidation was also evaluated. This study provides new insight into the enhancement of S2O82-/Fe2+ oxidation for sludge dewatering based on polarity analysis of EPS.
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Affiliation(s)
- Liangliang Wei
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China; College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, China.
| | - Xinhui Xia
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Fengyi Zhu
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Qiaoyang Li
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Mao Xue
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jianju Li
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Bo Sun
- College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, China
| | - Junqiu Jiang
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Qingliang Zhao
- State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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46
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Hu W, Tan J, Pan G, Chen J, Chen Y, Xie Y, Wang Y, Zhang Y. Direct conversion of wet sewage sludge to carbon catalyst for sulfamethoxazole degradation through peroxymonosulfate activation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 728:138853. [PMID: 32353802 DOI: 10.1016/j.scitotenv.2020.138853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/15/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
The high moisture content of wet sewage sludge generated from wastewater treatment process not only brings high cost of sewage disposal, but also limits its utilization as resource. In this study, an efficient strategy of directly utilizing wet sludge to develop advanced carbocatalyst via a hydrothermal coupled pyrolysis process was proposed. The possible application of as-synthesized carbocatalyst was evaluated by activating peroxymonosulfate (PMS) to degrade a model pollutant of sulfamethoxazole (SMX). Experimental results showed that about 100% of SMX and 59% of total organic carbon (TOC) could be removed within 15 min. Moisture content in wet sludge also affected the performances of as-obtained carbocatalysts. Further studies verified that singlet oxygen (1O2) dominated SMX degradation, which was generated in the process of PMS activation by CO groups on the surface of carbocatalyst. In the preliminary ecological test, a lower ecotoxicity of SMX degradation solution compared with the original solution was observed. This study demonstrated the feasibility of directly utilizing wet sludge for advanced carbocatalyst fabrication, which provided another solution for wet sludge treatment and utilization.
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Affiliation(s)
- Wanrong Hu
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Jiangtao Tan
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Guohua Pan
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Jie Chen
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Yundi Chen
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Yi Xie
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Yabo Wang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Yongkui Zhang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
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47
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Chen D, Dou Y, Tang Q, Huang Y, Song M, Peng F. New Insight on the Combined Effects of Hydrothermal Treatment and FeSO 4/Ca(ClO) 2 Oxidation for Sludge Dewaterability Improvement: Moisture Distribution and Noncovalent Interaction Calculation. ACS OMEGA 2020; 5:15891-15900. [PMID: 32656409 PMCID: PMC7345395 DOI: 10.1021/acsomega.0c00995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
A combination of hydrothermal treatment and FeSO4/Ca(ClO)2 oxidation was developed in our previous work and was proved to be significantly useful for improving the sludge dewaterability. The dewatering mechanism of the sludge after the combined treatment of hydrothermal treatment and FeSO4·7H2O/Ca(ClO)2 was obtained for the first time based on the moisture distribution analysis. Moreover, the noncovalent interaction between the hydrophilic sites of sludge EPS in sludge and water molecules was studied for the first time by using density functional theory. The electrostatic potentials of three representative EPS molecules, that is, dextran, poly-gamma-glutamate, and poly-l-lysine, were calculated and analyzed. AIM and RDG of the representative EPS·water complex models were calculated to study the noncovalent interaction mechanism. The moisture distribution and noncovalent interactions analyzed in this paper will provide information for improving sludge dewatering performance.
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Affiliation(s)
- Dandan Chen
- Engineering
Laboratory for Energy System Process Conversion & Emission Control
Technology of Jiangsu Province, School of Energy & Mechanical
Engineering, Nanjing Normal University, Nanjing 210023, China
- Key
Laboratory of Energy Thermal Conversion and Control of Ministry of
Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
- China
Construction Power and Environment Engineering Co., LTD, Nanjing 210017, China
| | - Yuhao Dou
- Engineering
Laboratory for Energy System Process Conversion & Emission Control
Technology of Jiangsu Province, School of Energy & Mechanical
Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Qin Tang
- Engineering
Laboratory for Energy System Process Conversion & Emission Control
Technology of Jiangsu Province, School of Energy & Mechanical
Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Yaji Huang
- Key
Laboratory of Energy Thermal Conversion and Control of Ministry of
Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Min Song
- Key
Laboratory of Energy Thermal Conversion and Control of Ministry of
Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Feirong Peng
- China
Construction Power and Environment Engineering Co., LTD, Nanjing 210017, China
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48
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Liu X, Zhai Y, Li S, Wang B, Wang T, Liu Y, Qiu Z, Li C. Hydrothermal carbonization of sewage sludge: Effect of feed-water pH on hydrochar's physicochemical properties, organic component and thermal behavior. JOURNAL OF HAZARDOUS MATERIALS 2020; 388:122084. [PMID: 31972434 DOI: 10.1016/j.jhazmat.2020.122084] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 12/21/2019] [Accepted: 01/12/2020] [Indexed: 06/10/2023]
Abstract
In this study, hydrothermal carbonization (HTC) of sewage sludge(SS) was carried out at a temperature of 270℃ and a resulting pressure of 7-9 MPa with 2 h. The effect of feed water pH values in the range of 2-12 on hydrochar characteristics, organic component and thermal behavior was evaluated. The result shows that with the pH value increasing, ash content shows a trend of decline, and organic components in the hydrochar become significantly simpler than SS. hydrochar is more beneficial to produce a fatty substance during an acidic environment and alkaline environments favor the formation of N-containing organic compounds and ketone organics, especially in strongly alkaline environments. Compared to the SS, hydrochar burning interval shortened 100℃ and the combustion of hydrochar is more durable. Considering the organic composition and combustion performance of hydrochar, it is found that the hydrochar prepared under 270-5 condition has the best effect.
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Affiliation(s)
- Xiangmin Liu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Yunbo Zhai
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
| | - Shanhong Li
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Bei Wang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Tengfei Wang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Yali Liu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Zhenzi Qiu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Caiting Li
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
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49
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Gao J, Wang Y, Yan Y, Li Z, Chen M. Protein extraction from excess sludge by alkali-thermal hydrolysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:8628-8637. [PMID: 31904100 DOI: 10.1007/s11356-019-07188-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
The protein in excess sludge can be extracted effectively by the alkali-thermal method, and the extracted protein can be used as a foaming agent and in other industrial raw materials to realize its resource utilization. In this paper, the factors influencing sludge protein extraction by the alkali-thermal method were optimized based on the protein extraction rate and the polypeptide content, which determine the foaming performance of the extracted protein. The results showed that the optimal conditions were a pH of 12, a temperature of 120 °C, a reaction time of 4 h, and a sludge moisture content of 92%. Under these optimized conditions, the extraction rate of protein and the concentration of polypeptides were 88.3% and 6599 mg/L, respectively. Additionally, the foaming performance of the extracted protein solution was tested, and the foamability and foam stability were close to 450% and 88.8%, respectively. Therefore, the sludge protein extracted by the alkali-thermal method can meet the relevant standards of foam extinguishing agents and concrete foaming agents in China. In addition, the dewatering performance of the hydrolyzed sludge was improved by 93.1%, which provided favorable conditions for the subsequent separation of the protein solution.
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Affiliation(s)
- Jianlei Gao
- School of Water Conservancy Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Yingchun Wang
- School of Water Conservancy Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Yixin Yan
- School of Water Conservancy Engineering, Zhengzhou University, Zhengzhou, 450001, China.
| | - Zheng Li
- Zhengzhou University Multi-Functional Design and Research Academy Co, Zhengzhou, 450002, China
| | - Manli Chen
- Zhengzhou University Multi-Functional Design and Research Academy Co, Zhengzhou, 450002, China
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50
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Maqbool T, Cho J, Shin KH, Hur J. Using stable isotope labeling approach and two dimensional correlation spectroscopy to explore the turnover cycles of different carbon structures in extracellular polymeric substances. WATER RESEARCH 2020; 170:115355. [PMID: 31811990 DOI: 10.1016/j.watres.2019.115355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 06/10/2023]
Abstract
Extracellular polymeric substances (EPS) from activated sludge comprise many organic constituents with polysaccharides and proteins as the main components of two different functionalities. Despite a number of previous EPS studies, a fundamental question remained unanswered, namely, whether the different EPS components would have the same turnover cycle (i.e., formation/dissolution) in biological wastewater treatment systems. In this study, we employed a stable isotope labeling approach based on isotope-enriched substrates (i.e., 13C-glucose and 15NH4Cl) to examine the potential discrepancies in the turnover cycles among different major EPS constituents. Our results, based on substrate consumption in a batch bioreactor, evidenced the existence of differences in carbon and nitrogen cycles within bulk EPS with an earlier replenishment of organic carbon relative to organic nitrogen. The changes in the 13C nuclear magnetic resonance (13C NMR) spectra of EPS with operation clarified the relative differences in the turnover periods among several identified EPS structures with different chemical functionalities. Two-dimensional correlation spectroscopy (2D-COS) on the 13C NMR spectra further showed that the substrate-assimilated carbon functional groups appear to preferably formed within bulk EPS in the order of O-alkyl carbons > amides > α amino acids > aliphatic carbons. This study provides a novel insight into the dissimilar formation rates of different EPS structures after substrate assimilation. This isotope labeling approach can be further applied to determine the mass balance among the substrate, biomass, and bound/soluble EPS within activated sludge systems.
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Affiliation(s)
- Tahir Maqbool
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea
| | - Jinwoo Cho
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea
| | - Kyung Hoon Shin
- Department of Environmental Marine Sciences, Hanyang University, Ansan, Gyeonggi do, 15588, South Korea
| | - Jin Hur
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea.
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