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Li S, Zhang D, Zhu R, Ma T, Liu M, Ma L, Wang Y. An intelligent system for precise management of coagulants in sludge conditioning: Inspired by the exploratory behavior in primates using senses. WATER RESEARCH 2025; 283:123842. [PMID: 40408987 DOI: 10.1016/j.watres.2025.123842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2025] [Revised: 04/25/2025] [Accepted: 05/14/2025] [Indexed: 05/25/2025]
Abstract
Coagulation conditioning is a key step for sludge dewatering, while the control of optimal coagulant dosing is still a challenge. This study proposes an intelligent system for the precise management of coagulants (IISPMC) in sludge conditioning. This system was assembled using an electrical impedance spectroscopy (EIS)-based sensor and a decision-making model to conduct the self-perception, decision-making, execution, and dosage optimization in sludge conditioning through a feedback-driven exploratory trial process, conceptually inspired by structured exploration behavior observed in primates. Using the optimal dosage obtained by the traditional manual jar test as the reference, the accuracy and repeatability of the IISPMC were investigated. The robustness under different perturbed conditions, reliability, and generalizability of the IISPMC were further assessed. Moreover, the long-term operational capability and the feasibility of the application in the scaled-up conditioning were also discussed. The results showed that the intelligent system achieved statistical median accuracy and repeatability of approximately 5 %, good reliability with a 5 g/kg resolution (R2 > 0.94 in validation tests) in determining the optimal coagulant dosage, and strong robustness under sludge conductivity and concentration perturbed conditions. In addition, the performance of the IISPMC was validated across different sludge sources, including activated sludge, dredged sediment, and algal sludge, as well as different coagulants, exhibiting solid generalizability. The system also demonstrated stable continuous operation over 40 batches, which is equivalent to the number of continuous operation batches of a small-sized treatment plant over approximately half a month. Furthermore, even after scaling up the conditioning tank, the IISPMC maintained stable performance. These findings highlight the potential of the IISPMC for practical applications in sludge conditioning.
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Affiliation(s)
- Shuxin Li
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Daxin Zhang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
| | - Rongxi Zhu
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Tengchong Ma
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Meilin Liu
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Luyao Ma
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yili Wang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China; Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
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2
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Blagojevič M, Bizjan B, Zupanc M, Gostiša J, Perše LS, Centa UG, Stres B, Novak U, Likozar B, Rak G, Repinc SK. Preliminary analysis: Effect of a rotary generator of hydrodynamic cavitation on rheology and methane yield of wastewater sludge. ULTRASONICS SONOCHEMISTRY 2024; 107:106943. [PMID: 38852537 PMCID: PMC11217745 DOI: 10.1016/j.ultsonch.2024.106943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 05/10/2024] [Accepted: 06/04/2024] [Indexed: 06/11/2024]
Abstract
Slightly acidic (pH 5.1) waste sludge with 4.7 % Total Solids (TS) was treated on a laboratory scale pined disc rotary generator of hydrodynamic cavitation (PD RGHC). Influence of four rotor discs with different number of cavitation generation units (CGUs) was investigated: 8-pins, 12-pins, 16-pins and 8-prism elements. The effect of hydrodynamic cavitation (HC) was investigated by analyzing rheological properties, surface tension, dewaterability, and particle size distribution. After subjecting the sludge to 30 cavitation passes, the dewatering ability of the sludge significantly decreased, resulting in a more than two-fold increase in Capillary Suction Time (CST). All regimes were successful in disintegrating particles to smaller sizes. A slight increase of sludge surface tension was measured post cavitation. Cavitated samples displayed a zero-shear viscosity, in contrast to the untreated sample, where viscosity noticeably increased as shear stress decreased. HC did not improve methane yield. Statistically significant correlations between physio-chemical properties and apparent viscosity at low shear stress were identified. Although there were no discernible statistical differences in sludge characteristics, some trends are visible among investigated CGU designs and warrant further research.
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Affiliation(s)
- Marko Blagojevič
- Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, 1000 Ljubljana, Slovenija
| | - Benjamin Bizjan
- Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, 1000 Ljubljana, Slovenija; Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva cesta 6, 1000 Ljubljana, Slovenija
| | - Mojca Zupanc
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva cesta 6, 1000 Ljubljana, Slovenija
| | - Jurij Gostiša
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva cesta 6, 1000 Ljubljana, Slovenija
| | - Lidija Slemenik Perše
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva cesta 6, 1000 Ljubljana, Slovenija
| | - Urška Gradišar Centa
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva cesta 6, 1000 Ljubljana, Slovenija
| | - Blaž Stres
- Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, 1000 Ljubljana, Slovenija; National Institute of Chemistry, Hajdrihova ulica 19, 1000 Ljubljana, Slovenija; Jozef Stefan Institute, Ljubljana, Slovenia, Jamova cesta 39, 1000 Ljubljana, Slovenija; Biotechnical Faculty, University of Ljubljana, Jamnikarjeva ulica 101, 1000 Ljubljana, Slovenija
| | - Uroš Novak
- National Institute of Chemistry, Hajdrihova ulica 19, 1000 Ljubljana, Slovenija
| | - Blaž Likozar
- National Institute of Chemistry, Hajdrihova ulica 19, 1000 Ljubljana, Slovenija
| | - Gašper Rak
- Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, 1000 Ljubljana, Slovenija
| | - Sabina Kolbl Repinc
- Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova cesta 2, 1000 Ljubljana, Slovenija; National Institute of Chemistry, Hajdrihova ulica 19, 1000 Ljubljana, Slovenija.
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3
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Lu Y, Huang M, Wang B, Zhou Q, Hu Y, Xue H. Effects of residual foaming agent and defoamer on defoaming-flocculation-filterpress characteristics of earth pressure balance shield muck. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:43080-43095. [PMID: 38888824 DOI: 10.1007/s11356-024-33946-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: 11/28/2023] [Accepted: 06/04/2024] [Indexed: 06/20/2024]
Abstract
Foaming agents as a combination of several components are usually used as soil conditioning during earth pressure balance shield (EPBS) tunnelling. These residues in waste EPBS muck lead to a series of new challenges for in-situ recycling, i.e., foams overflow flocculation tank. This study investigates the effects of residual foaming agent components and defoamers on defoaming-flocculation-filterpress characteristics of EPBS muck using an improved flocculation and filterpress system. Residual foam height (Hf), defoaming ratio (DFR), antifoaming ratio (AFR), total suspended substance (TSS), turbidity, moisture content (MC), and zeta potential (ZP) were selected as characterization indices. The microstructure of filterpress cakes was analyzed using a scanning electron microscope. Results demonstrate that an enhancement within 0.0-1.0wt.% for sodium fatty alcohol polyoxyethylene ether sulfate (AES) and alpha olefin sulfonate (AOS) significantly reduces DFR and AFR. The MC and ZP decline, while the Hf and turbidity enhance. The combinations of nonionic surfactants alkyl polyglycoside (APG) and fatty alcohol-polyoxyethylene ether (AEO) in a concentration range of 0.0-1.0wt.% with 0.2wt.% AES causes the Hf, DFR, AFR, turbidity, and ZP to exhibit absolutely different variations. The MC with the growth in both APG and AEO presents a trend of first decreasing and then increasing. By increasing foam stabilizers sodium carboxymethyl cellulose (CMC) and guar gum (GG) within 0.02-0.10wt.%, the AFR, TSS, and ZP enhance in varying degrees, while the Hf, DFR, and MC gradually reduce. With the increase of defoamers hydroxyl silicone oil-glycerol polyoxypropylene ether (H-G) and dimethyl silicone oil-glycerol polyoxypropylene ether (D-G) within 0.002-0.010wt.%, the DFR and AFR are significantly improved, while the TSS, turbidity, MC, and ZP display varying degrees of reduction. Moreover, defoaming-flocculation-filterpress mechanisms of EPBS muck are explored to provide a useful reference for actual in-situ recycling projects.
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Affiliation(s)
- Yao Lu
- School of Civil Engineering, Fuzhou University, Fuzhou, China
| | - Ming Huang
- School of Civil Engineering, Fuzhou University, Fuzhou, China.
| | - Bingnan Wang
- School of Civil Engineering, Fuzhou University, Fuzhou, China
| | - Qi Zhou
- School of Civil Engineering, Fuzhou University, Fuzhou, China
| | - Yanfeng Hu
- Xiamen Branch, CCCC First Highway Engineering Group Co, Ltd., Xiamen, China
| | - Huakun Xue
- Xiamen Branch, CCCC First Highway Engineering Group Co, Ltd., Xiamen, China
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Hou J, Hong C, Ling W, Hu J, Feng W, Xing Y, Wang Y, Zhao C, Feng L. Research progress in improving sludge dewaterability: sludge characteristics, chemical conditioning and influencing factors. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119863. [PMID: 38141343 DOI: 10.1016/j.jenvman.2023.119863] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/29/2023] [Accepted: 12/12/2023] [Indexed: 12/25/2023]
Abstract
Sludge from wastewater treatment processes with high water content and large volume has become an inevitable issue in environmental management. Due to the challenging dewatering properties of sludge, current mechanical dewatering methods are no longer sufficient to meet the escalating water content standards of sludge. This paper summarizes the characteristics of various sludge and raises reasons for the their dewaterability differences. Affected by extracellular polymeric substances, biological sludge is hydrophilic and negatively charged, which limits the dewatering degree. The rheological properties, flocs, ionic composition, and solid phase concentration of the sludge also influence the dewatering to some extent. For these factors, the chemical conditioning measures with simple operation and excellent effect improve its dewaterability, which mainly include flocculation/coagulation, acid/alkali treatment, advanced oxidation, surfactant treatment and combined treatment. There is a growing necessity to explore the development of new chemical conditioning agents, even though traditional agents continue to remain widely used. However, the development of these new agents should prioritize finding a balance between various factors such as efficiency, effectiveness, ease of operation, environmental safety, and cost-effectiveness. Electrochemical dewatering enhances solid-liquid separation, and its coupling with chemical conditioning is also an excellent means to further reduce water content. In addition, the improvement of press filter is an effective way, which is influenced by pressure, processing time, sludge cake thickness and pore structure, filter media etc. In general, it is essential to develop new conditioning agents and enhance mechanical filtration press technology based on a thorough understanding of various sludge properties. Concurrently, an in-depth study of the principles of mechanical pressure filtration will contribute to establishing a theoretical foundation for effective deep sludge dewatering and propel further advancements in this field.
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Affiliation(s)
- Jiachen Hou
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Chen Hong
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083, China.
| | - Wei Ling
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Jiashuo Hu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Weibo Feng
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yijie Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Chengwang Zhao
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Lihui Feng
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
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Deng R, Lai J, Liu Z, Song B, Liu H, Chen D, Zuo G, Yang Z, Meng F, Gong T, Song M. Insights into the role of ·OH generated in Fe 2+/CaO 2/coal slime system for efficient extracellular polymeric substances degradation to improve dewaterability of sewage sludge. CHEMOSPHERE 2023; 326:138443. [PMID: 36935059 DOI: 10.1016/j.chemosphere.2023.138443] [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: 12/28/2022] [Revised: 03/07/2023] [Accepted: 03/17/2023] [Indexed: 06/18/2023]
Abstract
The disposal of massive sewage sludge and coal slime is a problem facing municipalities in China. A hypothesis for the co-disposal of sludge and coal slime is proposed to improve dewaterability by utilizing the beneficial role of coal slime as a filter assist and CaO2 enhanced system in this research. Results showed that capillary suction time, specific resistance to filtration and water content decreased dramatically from 49.3 s, 13.2 × 1012 m/kg and 84.85% to 19.1 s, 1.0 × 1012 m/kg and 50.07%, respectively, under the optimal conditions with 0.3/0.1/0.3-Fe2+/CaO2/coal slime g/g DS. The hydroxyl radicals generated in the Fe2+/CaO2 process acted on extracellular polymeric substances (EPS), resulting in a drop in the ratio of α-helix/(β-sheet + random coil) in the secondary structure of EPS proteins and a reduction in the concentration of aromatic proteins and tryptophan-like substances in TB-EPS, thereby enhancing the sludge dewaterability. Furthermore, coal slime as the skeleton building material induced a rise in sludge particle size and contact angle, lowering the hydrophilicity, compressibility of sludge and providing more channels to facilitate water flow. This work verified the promising application prospect of the Fe2+/CaO2/coal slime combined system in the enhancement of sludge dewaterability.
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Affiliation(s)
- Rong Deng
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Jiahao Lai
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Zonghao Liu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Bing Song
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Huan Liu
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430070, China
| | - Dandan Chen
- School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Gancheng Zuo
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Zhen Yang
- School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu 210023, China
| | - Fanyue Meng
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Tingting Gong
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China
| | - Min Song
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China.
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Zhu L, Yang P, Wang K, Lyu W. Efficient dewatering of unclassified tailings with flocculant: role of ultrasound. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:60354-60366. [PMID: 37022544 DOI: 10.1007/s11356-023-26676-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/23/2023] [Indexed: 05/10/2023]
Abstract
Flocculants play an important role in the solid-liquid separation of tailings slurry, and its dosage directly impacts on the dewatering efficiency of tailings. Herein, the influence of ultrasonication on flocculant dosage in dehydration process of unclassified tailings was studied. The effects of flocculant dosage on initial settling rate (ISR), underflow concentration, and effective settling time in the process were investigated in detail. The directivity characteristics of ultrasound transducers with different frequencies in unclassified tailings slurry was simulated by MATLAB. The morphologies of underflow tailings at different flocculant dosages were detected by environmental scanning electron microscope (E-SEM). The relationship between flocculant dosage and fractal dimension (DF) was quantitatively analyzed based on fractal theory. The influence mechanism of flocculant on the settling and thickening of unclassified tailings was revealed. The results show that the optimum flocculant dosage for the ultrasonically treated tailings slurry is 40 g/t, at which the ISR reach a maximum value of 0.262 cm/min and the final underflow concentration (FUC) reach a maximum value in 60 min. Compared with settling without ultrasonication, the optimum flocculant dosage is reduced by 10 g/t, the ISR increases by 10.45%, the effective settling time is reduced by 50 min, and the FUC increases by 1.65%. The fractal dimension of underflow tailings first increases and then decreases with the increase in flocculant dosage, the relationship of which is in accordance with Lorentz model.
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Affiliation(s)
- Liyi Zhu
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, T6G 2V4, Canada
| | - Peng Yang
- Beijing Key Laboratory of Information Service Engineering, Beijing Union University, Beijing, 100101, China
| | - Kun Wang
- College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Wensheng Lyu
- School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
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Odor reduction using hydrogen sulfide-removing bacteria in sludge filtration systems: Ferrous-oxidizing bacteria and sulfur-oxidizing bacteria. J Biosci Bioeng 2023; 135:395-401. [PMID: 36878769 DOI: 10.1016/j.jbiosc.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/20/2023] [Accepted: 02/20/2023] [Indexed: 03/07/2023]
Abstract
The preconditioning of digested sludge in sludge filtration systems produces hydrogen sulfide (H2S), a major odor-causing source. This study evaluated the effects of adding H2S-removing bacteria to sludge-filtration systems. Ferrous-oxidizing bacteria (FOB) and sulfur-oxidizing bacteria (SOB) were mass-cultivated in a hybrid bioreactor equipped with an internal circulation system. In this bioreactor, FOB and SOB effectively removed >99% of H2S; however, the acidic conditions created by adding a coagulant during digested sludge preconditioning were more favorable for FOB than for SOB. In batch tests, SOB and FOB removed 94 ± 1.1% and 99 ± 0.1% of H2S, respectively; therefore, digested sludge preconditioning proved more suitable for FOB activity than SOB activity. The results revealed that the optimal FOB addition ratio was 0.2%, validated using a pilot filtration system. Moreover, the 57.5 ± 2.9 ppm H2S generated in the sludge preconditioning step was reduced to 0.01 ± 0.01 ppm after adding 0.2% FOB. Therefore, the results of this study will be useful because they provide a process for biologically removing odor-causing sources without affecting the dewatering efficiency of the filtration system.
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Hua L, Shuai L, Ze-Xiang L, Xi L, Hai-Nong S, Cheng-Rong Q, Zhi-Wei W, Shuang-Fei W, Jian Z. Retardation of sludge calcification by blocking the transportation of Ca2+ into anaerobic granular sludge. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2023.131112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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9
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Li J, Ru S, Yuan C, Wu B, Ji Y, Dai Z, Lei Z, Zhang Z, Yuan T, Li F, Liu M. An all-organic conditioning method to achieve deep dewatering of waste activated sludge and the underlying mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 327:116923. [PMID: 36470188 DOI: 10.1016/j.jenvman.2022.116923] [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: 06/16/2022] [Revised: 11/04/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Among the common treatment/disposal routes of excessive activated sludge from municipal wastewater treatment plant, dewatering process functions as an essential pre-/post-treatment for volume minimization and transportation facilitation. Since inorganic coagulants have long been criticized for their high dosage and solid residue in sludge cake, there is an urgent need for investigations regarding the potential of applying organic chemicals as the conditioner. In this study, combined use of poly dimethyldiallylammonium chloride (PDMD) and tannic acid (TA) were investigated as an all-organic co-conditioning method for sewage sludge pre-treatment. Results showed that this all-organic conditioning strategy can effectively improve the dewaterability of sewage sludge. The capillary suction time reduced from 128.8 s to 23.1 s, and the filtration resistance reduced from 1.24 × 1012 cm/g to 7.38 × 1010 cm/g. The moisture content of dewatered sludge cake decreased to as low as 55.83%, showing the highest dewatering efficiency reported so far. In addition, the combination of PDMD and TA maximized the treating efficiency with very limited consumption of conditioners (added up to 4% of total solid). Based on the physic-chemical and rheological property investigation, it was proposed that the intermediate molecular weight polymer-based flocculation process and the TA agent-based protein precipitation process, could remarkably strengthen the compactness and structure robustness of sludge. In all, this PDMD-TA-based conditioning method suggested practical significance in consideration of its cost-effectiveness and disposal convenience of sludge cake.
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Affiliation(s)
- Jie Li
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China.
| | - Shaoqin Ru
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Chenwei Yuan
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Bo Wu
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Yiwen Ji
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Zijun Dai
- School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444, China
| | - Zhongfang Lei
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Zhenya Zhang
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Tian Yuan
- Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Fengting Li
- College of Environmental Science & Engineering, State Key Laboratory of Pollution Control and Resource Reuse Study, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Misha Liu
- National Engineering Research Center of Dredging Technology and Equipment, 10 Gucui Road, Shanghai, 201314, China; Faculty of Life and Environmental Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.
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10
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Feng Q, Guo K, Gao Y, Liu B, Yue Q, Shi W, Feng C, Zhou J, Wang G, Gao B. Effect of coagulation treatment on sludge dewatering performance: Application of polysilicate and their mechanism. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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11
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Zhang X, Zhang H, Liu T, Yang J, Wang Z, Chen P. Insights into the respective role of oxidation and flocculation conditioning for enhancing paper sludge dewaterability. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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12
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Reinterpretation of the mechanism of coagulation and its effects in waste activated sludge treatment. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Li X, Shi Y, Zhou X, Wang L, Zhang H, Pi K, Gerson AR, Liu D. Adaptability of organic matter and solid content to Fe 2+/persulfate and skeleton builder conditioner for waste activated sludge dewatering. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:14819-14829. [PMID: 34617233 DOI: 10.1007/s11356-021-16404-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: 03/19/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Sludge conditioning is important for improved dewatering, with the sludge characteristics impacting the effect of conditioning. A composite conditioner, Fe2+-activated sodium persulfate (Fe2+/SPS) combined with phosphogypsum (PG), was used to examine its impact on sludges with different organic contents (34.6-43.8%) or different solid contents (2.8-5.9%). Response surface optimization analysis shows that when the best conditioning is achieved, the reduction of the specific resistance to filtration (SRF) is not sensitive to organic matter content, but the dewatering performance of the sludge is greatly affected by the solid content. The oxidation role of Fe2+/SPS and the skeleton builder role of PG together affect the conditioning, oxidation playing a major role in conditioning, especially for greater organic matter content. The organic content (maximum ηSOL value was 0.32) also affects the effectiveness of the skeleton builder more than the solid content (Maximum ηSOL value was 0.25). Changes in PG significantly impacts the optimal molar ratio and dosage of Fe2+/SPS. Sludge with greater solid content requires greater Fe2+/SPS dosage to provide stronger oxidation to destroy flocs, and the maximum Fe2+:SPS molar ratio was 1.14 with solid content of 5.9 wt%. The composite conditioning decreases the content of extracellular polymeric substances and proteins/polysaccharides. This study provides new insight into the relationship between the oxidation role of Fe2+/SPS and the skeleton builder role of PG for sludge conditioning strategies according to the optimal conditions.
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Affiliation(s)
- Xiaoran Li
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Yafei Shi
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China.
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, Wuhan, 430068, Hubei, China.
| | - Xi Zhou
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Lu Wang
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Huiqin Zhang
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Kewu Pi
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, Wuhan, 430068, Hubei, China
| | - Andrea R Gerson
- Blue Minerals Consultancy, Wattle Grove, Tasmania, 7109, Australia
| | - Defu Liu
- School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, Hubei, China
- Hubei Key Laboratory of Ecological Restoration for River-Lakes and Algal Utilization, Wuhan, 430068, Hubei, China
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14
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Feng J, Zhang T, Sun J, Zhu J, Yan W, Tian S, Xiong Y. Improvement of sewage sludge dewatering by piezoelectric effect driven directly with pressure from pressure filtration: Towards understanding piezo-dewatering mechanism. WATER RESEARCH 2022; 209:117922. [PMID: 34890911 DOI: 10.1016/j.watres.2021.117922] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 06/13/2023]
Abstract
Piezoelectric effect was firstly employed to improve dewatering efficiency of sludge. It was found that the piezoelectric effect could be driven directly by the pressure of pressure filtration process, without any additional energy. This piezo-dewatering process coupled piezoelectric effect with pressure filtration could efficiently remove moisture of sludge. Under 0.6 MPa for 2 h, moisture content (MC) and weight of sludge could be reduced to 63.9% and 3.2 g from 96.7% and 50 g by the piezo-dewatering process with 0.45 g t-BaTiO3. This piezo-dewatering efficiency was much higher than that of usual conditioning-pressure filtrations using CaO, FeCl3 or polyacrylamide (PAM) as the conditioners. And the piezo-dewatering process assisted by PAM could further decrease MC and weight of the sludge to 54.9% and 2.1 g, correspondingly, which complied to the advanced dewatering requirement (MC < 60%). The favorable piezo-dewatering efficiency was contributed to the piezo-catalytic oxidation and the electric role of remnant piezo-field. The finding of this piezo-dewatering mechanism offered an inspiring look at developing the emerging dewatering technology.
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Affiliation(s)
- Jinxi Feng
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China
| | - Tiantian Zhang
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Henan Institute of Surveying and Mapping Engineering, No.8, Huanghe Road, Zhengzhou 450003, PR China
| | - Jingxiang Sun
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China
| | - Jinzhu Zhu
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China
| | - Wen Yan
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China
| | - Shuanghong Tian
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China
| | - Ya Xiong
- School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China.
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15
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Zhao J, Li B, Wang A, Ge W, Li W. Floc formation and growth mechanism during magnesium hydroxide and polyacrylamide coagulation process for reactive orange removal. ENVIRONMENTAL TECHNOLOGY 2022; 43:424-430. [PMID: 32633211 DOI: 10.1080/09593330.2020.1791970] [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: 03/24/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Magnesium hydroxide is commonly used as a coagulant for treating reactive dyes wastewater. However, the flocs are relatively small and coagulation process needs longer sedimentation time. Large flocs and short operation time are important for good coagulation performance. Coagulation floc formation and growth processes using magnesium hydroxide and polyacrylamide (PAM) dual-coagulant were investigated with controlled experiments through flocculation index (FI), floc size distribution, zeta potential, scanning electron microscopy and Fourier transform infrared spectroscopy. The final average floc size reached 58.5 and 4.96 μm with and absence of PAM addition during slow mixing periods. PAM feeding time and magnesium hydroxide formation time can affect the floc formation and growth processes. The results showed that floc formed rapidly during magnesium hydroxide generation within 90 s and flocs aggregated together by PAM bridging function. Reactive orange removal efficiency reached 99.3% with rapid mixing 250 rpm at 90 s during 100 mg/L magnesium ion addition, then adding 6 mg/L PAM at the beginning of slow mixing period in dual-coagulant system.
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Affiliation(s)
- Jianhai Zhao
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, People's Republic of China
| | - Bo Li
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, People's Republic of China
| | - Anmin Wang
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, People's Republic of China
| | - Wenqi Ge
- School of Control and Mechanical Engineering, Tianjin Chengjian University, Tianjin, People's Republic of China
| | - Wenpu Li
- Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, People's Republic of China
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16
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Wang D, Chang X, Ma K. Predicting flocculant dosage in the drinking water treatment process using Elman neural network. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:7014-7024. [PMID: 34467491 DOI: 10.1007/s11356-021-16265-4] [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: 03/02/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
Predicting the flocculant dosage in the drinking water treatment process is essential for public health. However, due to the complexity of water quality and flocculation, many difficulties remain. The present study aimed to report on using artificial intelligence, namely, the Elman neural network (ENN), to predict the flocculant dosage and explore the applications of the proposed model in waterworks. The flocculation process of drinking water was introduced in this study, and four typical models were developed based on multiple linear regression (MLR), the radial basis function neural network (RBFNN), the least squares support vector machine (LSSVM), and the ENN. To improve the prediction accuracy, a mixed term including long-term data and short-term data was proposed to capture the periodic and time-varying characteristics of water quality data. The weights of each part are updated adaptively according to the comparison of effluent turbidity and set values. The results demonstrate that the proposed ENN model performed better than the other three models in terms of the prediction performance. With the ENN model of flocculant dosage, the root mean square error (RMSE), mean absolute percentage error (MAPE), and coefficient of determination (R2) of the test data were 1.8917, 5.0067, and 0.8999, which were improved by 36.9%, 41.5%, and 14.0% in comparison with the best one (RBFNN) of the other three models, respectively. The effluent turbidity of sedimentation tank was more stable under the control of proposed ENN model of flocculant dosage than the other three models. Considering its performance, the ENN model can be taken as a preferred data intelligence tool for predicting the drinking water flocculant dosage.
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Affiliation(s)
- Dongsheng Wang
- College of Automation & College of Artificial Intelligence, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
- Jiangsu Engineering Laboratory for Internet of Things and Intelligent Robots, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
| | - Xiao Chang
- College of Automation & College of Artificial Intelligence, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China
- Jiangsu Engineering Laboratory for Internet of Things and Intelligent Robots, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China
| | - Kaiwei Ma
- College of Automation & College of Artificial Intelligence, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
- Jiangsu Engineering Laboratory for Internet of Things and Intelligent Robots, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
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17
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Wang G, Ge D, Bai L, Dong Y, Bian C, Xu J, Zhu N, Yuan H. Insight into the roles of electrolysis-activated persulfate oxidation in the waste activated sludge dewaterability: Effects and mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 297:113342. [PMID: 34314959 DOI: 10.1016/j.jenvman.2021.113342] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/12/2021] [Accepted: 07/18/2021] [Indexed: 06/13/2023]
Abstract
Sludge dewatering, as one of the most important steps of sludge treatment, can facilitate transportation and improve disposal efficiency by reducing the volume of sludge. This study investigated the effects of electrolysis-activated persulfate oxidation on improving sludge dewaterability. The results indicated that the sludge capillary suction time (CST) and water content of dewatered sludge cake (Wc) reduced from 93.7 s and 87.8% to 9.7 s and 68.3% respectively at the optimized process parameters: electrolysis voltage of 40 V, electrolysis time of 20 min, and 1.2 mmol/g TS S2O82-. Correlation analysis revealed that the enhancement of sludge dewaterability was closely associated with the increased floc size and zeta potential, decreased protein content in three-layers extracellular polymeric substances (EPS) and viscosity (R = -0.868, p = 0.002; R = -0.703, p = 0.035; R ≥ 0.961, p < 0.001; R = 0.949, p < 0.001). Four protein fluorescence regions in EPS were analyzed by three-dimensional excitation-emission matrix parallel factor (3D-EEM-PARAFAC). The protein secondary structure was changed after the treatment, and the reduction of α-helix/(β-sheet + random coil) indicated that more hydrophobic sites were exposed. Analysis by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and rheological test demonstrated that the hydrophilic functional groups of the sludge were decreased and the sludge mobility was significantly enhanced after the treatment with electrolysis-activated persulfate oxidation. Moreover, bound water was converted to free water during SO4·- and ·OH generated by electrolysis-activated persulfate degraded EPS and attacked sludge cells. Meanwhile, scanning electron microscopy (SEM) images revealed that the treated sludge formed porous channel structures, which promoted the flowability of the water. These findings provide a new insight based on electrolysis-activated persulfate oxidation in sludge treatment for enhancing sludge dewaterability.
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Affiliation(s)
- Guanjun Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Dongdong Ge
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Lu Bai
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yanting Dong
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Chang Bian
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiajia Xu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
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18
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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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19
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Ge D, Zhu Y, Li G, Yuan H, Zhu N. Identifying the key sludge properties characteristics in Fe 2+-activated persulfate conditioning for dewaterability amelioration and engineering implementation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113204. [PMID: 34243089 DOI: 10.1016/j.jenvman.2021.113204] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Fe2+-activated persulfate process has been introduced into sludge conditioning currently, however the key sludge properties characteristics are worthwhile comprehensively considering for the engineering implementation and management. The results indicated that both the optimal dosages of persulfate and Fe2+ were 0.6 mmol/gTS for sludge dewaterability amelioration, and the reduction efficiencies of capillary suction time (CST), specific resistance of filtration (SRF), and water content (Wc) of dewatered sludge cake reached to 90.5%, 97.2%, and 22.4%, respectively. Significantly, the persulfate and Fe2+ exerted distinctive roles in the conditioning process. The increased persulfate could promote the oxidatively disintegrated effect on sludge flocs, rendering the decrease of particle size. With the oxidative decomposition of the negatively charged biopolymers, sludge zeta potential rose gradually. However, Fe2+ contributed to more persulfate activation to generate free radicals, and the produced Fe3+ could further electrically neutralize the broken sludge fragments. The core mechanism of Fe2+-activated persulfate conditioning is "destroying and re-building" of sludge flocs. Noteworthily, EPS protein was oxidatively degraded more preferentially than EPS polysaccharide, and the decrease of the α-helix content of EPS protein was conducive to the enhancement of sludge dewaterability. Furthermore, the hydrophilic functional groups reduced clearly and element chemical states on sludge flocs altered pronouncedly, also the destroyed structure and microchannel facilitated the flowability of water. These findings provide theoretical and technical support for the practical engineering implementation of the Fe2+-activated persulfate conditioning process.
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Affiliation(s)
- Dongdong Ge
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yidan Zhu
- Jinhua Academy of Agricultural Sciences, Jinhua, Zhejiang, 321025, China
| | - Guobiao Li
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haiping Yuan
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Nanwen Zhu
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
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20
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Ding N, Wang X, Jiang L, Zhang J, Geng Y, Dong L, Liu H. Enhancement of sludge dewaterability by a magnetic field combined with coagulation/flocculation: a comparative study on municipal and citric acid-processing waste-activated sludge. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:35728-35737. [PMID: 33675498 DOI: 10.1007/s11356-021-13278-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: 10/14/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
The difficulties in dewatering waste-activated sludge (WAS) using mechanical devices have caused great problems in sludge transportation and disposal. Herein, coagulation and flocculation are combined with the use of a magnetic field as a clean and low-energy physical treatment method to enhance the dewaterability of municipal and citric acid-processing WAS. It is shown that the use of the magnetic field had a significant effect on the capillary suction time (CST) of municipal WAS but not on the specific resistance filtration (SRF) and CST of the citric acid WAS. The differences in the magnetic field effects were due to differences in the sludge properties. For municipal WAS, the particle size decreased, the zeta potential remained unchanged, and the viscosity decreased, whereas in the citric acid WAS, the particle size increased, the absolute value of the zeta potential decreased, and the viscosity increased. In addition, these effects were also confirmed with studies of the water state and micro-morphology analyses. It is shown that the acidification of the municipal WAS and coagulation of citric acid WAS were likely the reasons for the enhancement of their dewaterability, respectively. This study confirmed that the use of a magnetic field combined with coagulation/flocculation may serve as an effective sludge conditioning method; however, the treatment conditions may vary with the sludge type.
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Affiliation(s)
- Ning Ding
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China.
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China.
- Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China.
| | - Xiao Wang
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Lin Jiang
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Jianxin Zhang
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Yue Geng
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
| | - Liming Dong
- State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, China
- School of Ecology and Environment, Beijing Technology and Business University, Fucheng Road No.11, Haidian District, Beijing, 100048, China
- Key Laboratory of Cleaner Production and Comprehensive Utilization of Resources, China National Light Industry, Beijing Technology and Business University, Beijing, China
| | - Hong Liu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Jiangsu Province, China
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21
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Naruka AK, Suganya S, Kumar PS, Amit C, Ankita K, Bhatt D, Kumar MA. Kinetic modelling of high turbid water flocculation using native and surface functionalized coagulants prepared from shed-leaves of Avicennia marina plants. CHEMOSPHERE 2021; 272:129894. [PMID: 33588143 DOI: 10.1016/j.chemosphere.2021.129894] [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: 10/27/2020] [Revised: 01/01/2021] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Coagulation performance of shed-leaves of Avicennia marina plants collected from Alang coastline, Gujarat (India) was scrutinized for the treatment of mud and starch water suspensions. For which, native, hydrochloric acid, sodium hydroxide and sodium chloride treated A. marina shed-leaves were processed with minimum environmental impact. Experiments were accomplished for the concentration of water suspensions (10-50 g/L) at the range of pH 7.0-8.0. The performances of these coagulants were assessed in terms of reduction in turbidity, pH, alkalinity, hardness, electrical conductivity and solids from water suspensions. The removal of bulk impurities was noted due to the floc formation of coagulant through hydrolysing salts, thus, resulted in the highest settlement at pH 7.82, 7.90 for mud and starch water, accordingly. Native and functionalized A. marina coagulants (AMCs) were characterized and interpreted using scanning electron microscopy, elemental analyses, energy dispersive and Fourier transform infrared spectroscopy. HCl treated AMC was relatively effective with good coagulation performance (96.76%), when compared with native and other treated AMCs. The turbidity removal by all AMCs obeyed with World Health Organization (WHO) acceptable limit of finished water, where HCl treated AMC clarified 15.15 and 16.36 NTU of mud and starch water suspensions to produce a clear water of 0.92 and 1.61 NTU, respectively. The proficiency of prepared AMCs were compared with other natural coagulants and surface functionalized (HCl > NaOH > NaCl) AMCs prepared in this study exerted better performance than the native AMC. The critical coagulation rate from the second-order kinetics were evaluated and the results were highly satisfying. Other physico-chemical parameters of water suspensions were evident for the adequate removal of impurities by non-toxic plant-based coagulants.
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Affiliation(s)
- Aruna Kanwar Naruka
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India
| | - Subburaj Suganya
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India
| | - Ponnusamy Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603 110, Tamil Nadu, India
| | - Chanchpara Amit
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India; Academy of Scientific and Innovative Research, Ghaziabad, 201 002, Uttar Pradesh, India
| | - Katakpara Ankita
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India
| | - Dhruv Bhatt
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India
| | - Madhava Anil Kumar
- Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India; Academy of Scientific and Innovative Research, Ghaziabad, 201 002, Uttar Pradesh, India.
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22
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Wang Q, Song L, Hui K, Song H. Iron powder activated peroxymonosulfate combined with waste straw to improve sludge dewaterability. ENVIRONMENTAL TECHNOLOGY 2021; 42:1302-1311. [PMID: 31487232 DOI: 10.1080/09593330.2019.1665111] [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: 06/10/2019] [Accepted: 08/31/2019] [Indexed: 06/10/2023]
Abstract
In an activated sludge system, the high hydrophilicity of extracellular polymeric substances (EPS) and the high compressibility of sludge greatly hinder sludge dewatering. A new method for improving the dehydration of waste activated sludge was explored by using iron powder activated peroxomonosulfate combined with waste straw (Fe0+PMS + WS). Specific resistance to filtration (SRF) and water content (Wc) were used to characterize the dewatering performance of sludge. Under the optimal measurement, Wc and SRF were significantly reduced. To reveal the synergistic effect of this joint treatment, zeta potential, particle size distribution, three-dimension excitation emission matrix (3D-EEM) fluorescence spectroscopy, bound water content analysis, and scanning electron microscopy (SEM) were used to investigate the mechanism of sludge dewatering. Results showed that the tightly bound EPS (TB-EPS) was oxidized by sulfate radicals (SO4-∙) to loose bound EPS (LB-EPS) and soluble EPS(S-EPS). SEM analysis displayed that the Fe0+PMS + WS combination regulated the formation of a more porous sludge filter cake structure. In addition, the low calorific value of the dewatered sludge after 12 h in open air was significantly increased, and the Wc of the dewatered sludge cake was reduced to 25%. These parameters were beneficial to the subsequent disposal of sludge.
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Affiliation(s)
- Qian Wang
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
| | - Lei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
| | - Kai Hui
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
| | - Hongwei Song
- School of Civil Engineering, Inner Mongolia University of Technology, Hohhot, People's Republic of China
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Liu J, Jia S, Xu L, Zhu F, Ren S, Liu Y, Sun Z. Application of composite degradable modified starch-based flocculant on dewatering and recycling properties. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 82:2051-2061. [PMID: 33263583 DOI: 10.2166/wst.2020.464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Sludge dewatering is an important step for wastewater treatment. Composite degradable flocculant (CDF) was prepared by cationic polyacrylamide (PAM) grafting onto modified starch with a novel initiator, and characterized by Fourier transform infrared spectroscopy. The microstructure of flocculated sludge was characterized by scanning electron microscopy. The study investigated the properties of CDF compared to PAM, which showed that the prepared CDF exhibited a highly effective flocculation on sludge dewatering, a higher transmittance and chemical oxygen demand removal rate, and a lower value of effluent ammonia nitrogen and total phosphorus. The fermentation process was also analyzed by testing the performance of dewatered sludge (temperature, pH, ammonia nitrogen, E4/E6 (humic acid absorbance at 465 nm (E4) and 665 nm (E6))). The dehydrated sludge with CDF could be easily compressed into cakes by belt-filter for easy transportation and storage. With the continuous addition of CDF and PAM, the corresponding index of capillary suction time (CST) increased. Moreover, the total value of CST with CDF was low, showing a good dewaterability. In addition, the sludge index of pumping time and moisture content with CDF were low in contrast with PAM. Fermentation experiments demonstrated that sludge with CDF had a comparatively high temperature and low value of E4/E6. Such novel CDF shows enormous potential in wastewater treatment and sludge fermentation.
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Affiliation(s)
- Jianbo Liu
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Shibei District, Qingdao, China E-mail: ; Sinocore Biotechnology (Qingdao) Co., Ltd, 53# Zhengzhou Road, Qingdao, 266042, China
| | - Shouhao Jia
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Shibei District, Qingdao, China E-mail:
| | - Liming Xu
- Sinocore Biotechnology (Qingdao) Co., Ltd, 53# Zhengzhou Road, Qingdao, 266042, China
| | - Feifei Zhu
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Shibei District, Qingdao, China E-mail:
| | - Shan Ren
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Shibei District, Qingdao, China E-mail:
| | - Yuanfeng Liu
- College of Environment and Safety Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Shibei District, Qingdao, China E-mail:
| | - Ziqi Sun
- Sinocore Biotechnology (Qingdao) Co., Ltd, 53# Zhengzhou Road, Qingdao, 266042, China
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24
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Influence of Sludge Initial pH on Bioleaching of Excess Sludge to Improve Dewatering Performance. COATINGS 2020. [DOI: 10.3390/coatings10100989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
pH has an important effect on the physiological activity of eosinophilic microorganisms. Therefore, this study used excess sludge produced by the mixed treatment of leachate and municipal sewage to explore the impact of different sludge initial pH on microbial biochemical reactions associated with the performance of excess sludge dehydration. Shake-flask tests were performed using inoculated microorganisms and fresh excess sludge in 500 mL Erlenmeyer flasks at a ratio of 1:4, with the addition of 2 g/L S0 and 6 g/L FeS2 as energy sources. Erlenmeyer flasks were shaken for 72 h at 180 rpm and 28 °C, in a reciprocating constant homeothermic oscillating water-bath. Results show that the specific resistance to filtration (SRF) of the bioleached excess sludge decreased from (1.45~6.68) × 1012 m/kg to (1.21~14.30) × 1011 m/kg and the sedimentation rate increased from 69.00~73.00% to 81.70~85.50%. The SRF decreased from 1.45 × 1012 m/kg to 1.21 × 1011 m/kg and the sedimentation rate increased from 69.00% to 85.00%, which both reached the highest level when the initial pH of the excess sludge was 5 and the bioleaching duration was 48 h. At this time, the rates of pH reduction and oxidative redox potential (ORP) reached the highest values (69.67% and 515 mV, respectively). Illumina HiSeq PE250 sequencing results show that the dominate microbial community members were Thiomonas (relative abundance 4.59~5.44%), which oxidize sulfur and ferrous iron, and Halothiobacillus (2.56~3.41%), which oxidizes sulfur. Thus, the acidic environment can promote microbial acidification and oxidation, which can help sludge dewatering. The presence of dominant sulfur oxidation bacteria is the essential reason for the deep dehydration of the bioleached sludge.
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25
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Liu W, Dong Z, Sun D, Dong Q, Wang S, Zhu J, Liu C. Production of bioflocculant using feather waste as nitrogen source and its use in recycling of straw ash-washing wastewater with low-density and high pH property. CHEMOSPHERE 2020; 252:126495. [PMID: 32199160 DOI: 10.1016/j.chemosphere.2020.126495] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Straw ash-washing wastewater is generated in the process of straw combustion power generation and potash fertilizer production. The suspended solid particles in straw ash-washing wastewater are hard to be settled down due to its low-density and high pH properties which inhibit the application of traditional chemical flocculants. Bioflocculant has good advantages in flocculating activity, biodegradability and adaptability of wastewater pH fluctuation. However, high production cost limited the large-scale applications of bioflocculant in wastewater treatment. In this study, the feasibility of using feather waste as cheap alternative nitrogen source of alkaliphilic Bacillus agaradhaerens C9 to produce bioflocculant was investigated. The results showed that strain C9 could simultaneously produce keratinase and bioflocculant, and thereby producing bioflocculant (named as BFF) using feather waste as cheap nitrogen source. The optimal fermentation conditions for enzymatic hydrolysis of feather waste and BFF production was 40 g/L feather wastes, 16 g/L glucose, 37 °C and pH 9.5, and the highest yield of 2.5 g/L was obtained. Moreover, BFF was used to flocculate straw ash-washing wastewater which exhibits low-density and high pH properties, and the highest flocculating rate of 93.1% was achieved when 6.0 mg/L BFF was added. This study reported for the first time that feather waste was used as inexpensive alternative nitrogen source for producing bioflocculant which could treat straw ash-washing wastewater, thereby promoting the resourceful utilization of feather waste and the reuse of straw ash-washing wastewater.
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Affiliation(s)
- Weijie Liu
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Zhen Dong
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Di Sun
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Qinxin Dong
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Shiwei Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xian, 710069, Shaanxi Province, China
| | - Jingrong Zhu
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China
| | - Cong Liu
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, China.
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26
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Qiang J, Zhou Z, Wang K, Qiu Z, Zhi H, Yuan Y, Zhang Y, Jiang Y, Zhao X, Wang Z, Wang Q. Coupling ammonia nitrogen adsorption and regeneration unit with a high-load anoxic/aerobic process to achieve rapid and efficient pollutants removal for wastewater treatment. WATER RESEARCH 2020; 170:115280. [PMID: 31759237 DOI: 10.1016/j.watres.2019.115280] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/05/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
In this study, an ammonium nitrogen (NH4+-N) adsorption and regeneration (AAR) was constructed by a zeolite-packed column and NaClO-NaCl regeneration unit, and coupled with an anoxic/aerobic (AO) system to achieve efficient removal of carbon, nitrogen and phosphorus under short hydraulic retention time (HRT) and sludge retention time (SRT). Compared to conventional anaerobic/anoxic/aerobic (AAO) process, the proposed AO-AAR process achieved more efficient and stable nitrogen removal with greatly shorter HRT (5.6 h) and SRT (8 d) at 10.4 °C, with NH4+-N and total nitrogen in the effluent below 1.5 and 8.0 mg/L, respectively. The AO-AAR also obtained efficient phosphorus removal (<0.5 mg/L) by dosing aluminum in aerobic tank. High load and short SRT deteriorated sludge settleability and dewaterability, but enhanced methane production by improving sludge biodegradability. Dosing aluminum made the AO operating module more stable with improved settleability and dewaterability, and further enhanced methane production. Short HRT and SRT also resulted in the thriving of filamentous bacteria (Thiothrix) and heterotrophic nitrifiers (Acinetobacter, Pseudomonas and Rhodobacter) in the AO module, which helped in enhancing denitrification potential and nitrification efficiency under low temperature. Long-term operation showed that exchange capacity and physicochemical properties of zeolite were unchanged under NaClO-NaCl regeneration by introducing the tail gas from aerobic tank into the used regenerant to remove Ca2+ and Mg2+ exchanged from effluent of the AO module. Techno-economic analysis showed that the AO-AAR process is attractive and sustainable for municipal wastewater treatment by significantly improving nitrogen removal, greatly reducing land occupancy, enhancing methane production and achieving efficient reduction of carbon dioxide emission.
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Affiliation(s)
- Jiaxin Qiang
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Zhen Zhou
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| | - Kaichong Wang
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Zhan Qiu
- Shanghai Chengtou Wastewater Treatment Co., Ltd, Shanghai, 201203, China
| | - Hui Zhi
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Yao Yuan
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Yubin Zhang
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Yuexi Jiang
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Xiaodan Zhao
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Zhiwei Wang
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Qiaoying Wang
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
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27
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Li Y, Song Z, Yuan Y, Zhang Q, Zhu H. Rheology improvement in an osmotic membrane bioreactor for waste sludge anaerobic digestion and the implication on agitation energy consumption. BIORESOURCE TECHNOLOGY 2020; 295:122313. [PMID: 31670203 DOI: 10.1016/j.biortech.2019.122313] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
Sludge rheology is an essential factor for anaerobic digestion (AD) processes to control the agitation energy consumption. In this study, the sludge rheology was characterized for an osmotic membrane bioreactor and a conventional sludge anaerobic digestion reactor as the solid content being increased from 3.5-3.7% to 7.5-7.7%. The flow curves were fitted using different rheological models and the mechanism was discussed. The sludge from the osmotic membrane bioreactor exhibited obviously better rheological properties than that of the conventional reactor at a solid content of 7.5-7.7%. Larger particles induced by less negative zeta potential and higher extracellular polymeric substances, together with the higher conductivity resulted by reverse salt flux in the osmotic membrane bioreactor, improved the sludge rheology due to reduced interactions between particles. As a result, the agitation energy consumption of the osmotic membrane bioreactor can save up to 34-39% compared with the conventional one at total solid content of 7.5-7.7%.
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Affiliation(s)
- Yunqian Li
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Zheyuan Song
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Yuan Yuan
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Qianqian Zhang
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Hongtao Zhu
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
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28
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Lv H, Liu D, Xing S, Wu D, Wang F, Yang J, Wu X, Zhang W, Dai X. The effects of aging for improving wastewater sludge electro-dewatering performances. J IND ENG CHEM 2019. [DOI: 10.1016/j.jiec.2019.08.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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29
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Feng G, Hu Z, Ma H, Bai T, Guo Y, Hao Y. Semi-solid rheology characterization of sludge conditioned with inorganic coagulants. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 80:2158-2168. [PMID: 32198333 DOI: 10.2166/wst.2020.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Rheology measurement, a state-of-the-art technology in a multitude of engineering disciplines, has often been used for computational fluid dynamic simulation of wastewater treatment processes, especially in anaerobic digestion and dewatering. In this work, rheological tests were used to study the semi-solid characteristics of sludge and a good result was obtained. The inorganic coagulants polyaluminum chloride (PAC) and ferric chloride (FC) both increased the floc strength of sludge, leading to higher rheology parameters such as elastic modulus, viscous modulus and specific thixotropy area. Curiously, the shape of all rheological curves exhibited little change with increasing coagulant dosage. The results indicated that various physical and chemical actions among coagulants and sludge flocs relate only to rigid structure, not to the nature of rheology behavior. Frequency sweep tests clearly showed that elastic modulus was a logarithmic function of frequency, suggesting that sludge could not properly be called a soft material due to its inorganic particles. An improved viscoelastic model was successfully developed to predict the experimental data of creep and recovery tests in the linear viscoelastic region. Furthermore, complicated viscoelastic behavior of sludge was also observed, and all the rheology tests could provide the optimum dosage of PAC but not the optimum dosage of FC.
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Affiliation(s)
- Guohong Feng
- School of Environment & Safety, Taiyuan University of Science & Technology, Taiyuan, 030024, China E-mail:
| | - Zhi Hu
- School of Environment & Safety, Taiyuan University of Science & Technology, Taiyuan, 030024, China E-mail:
| | - He Ma
- School of Environment & Safety, Taiyuan University of Science & Technology, Taiyuan, 030024, China E-mail:
| | - Tiantian Bai
- School of Environment & Safety, Taiyuan University of Science & Technology, Taiyuan, 030024, China E-mail:
| | - Yabing Guo
- School of Environment & Safety, Taiyuan University of Science & Technology, Taiyuan, 030024, China E-mail:
| | - Yiran Hao
- Xi'an JiaoTong University, Xi'an, 710049, China
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30
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Feng G, Bai T, Ma H, Hu Z, Guo Y, Tan W. Establishment of the Permeability Model for Soft Solid Sludge Conditioned with Flocculants. ACS OMEGA 2019; 4:18574-18581. [PMID: 31737816 PMCID: PMC6854576 DOI: 10.1021/acsomega.9b02332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Permeability plays a decisive role in the dewatering process and reflects the difficulty of filtration, especially for soft solid material such as sludge. In this paper, the physicochemical properties and dewatering performance of sludge conditioned with different kinds of flocculants were investigated. Results showed that the flocculant could change the sludge microstructure such as floc morphology, specific surface area, and fractal dimension. Compared with filtration pressure, flocculants had a greater influence on sludge permeability which was a significant negative correlation with filtration pressure and was a positive correlation with flocculant dosage. In order to describe the fact that fluid flows through the porous voids for soft solid sludge, the improved Kozeny constant was corrected. Research showed that permeability was more significant in the dewatering process for the sludge conditioned with inorganic flocculants than that with organic flocculants. The Kozeny constant was not only relevant with suspension nature but also with filtration pressure. The range of the improved Kozeny constant was reasonably determined based on flocculant type, concentration, and filtration pressure, which was of great help to project applications. For raw sludge, the improved Kozeny constant was 958 times than that of the original value, and it decreased significantly for conditioned sludge.
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Affiliation(s)
- Guohong Feng
- School
of Environment & Safety, Taiyuan University
of Science & Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan 030024, Shanxi, China
| | - Tiantian Bai
- School
of Environment & Safety, Taiyuan University
of Science & Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan 030024, Shanxi, China
| | - He Ma
- School
of Environment & Safety, Taiyuan University
of Science & Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan 030024, Shanxi, China
| | - Zhi Hu
- School
of Environment & Safety, Taiyuan University
of Science & Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan 030024, Shanxi, China
| | - Yabing Guo
- School
of Environment & Safety, Taiyuan University
of Science & Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan 030024, Shanxi, China
| | - Wei Tan
- School
of Chemical Engineering & Technology, Tianjin University, No. 135 Yaguan Road, JinNan District, Tianjin 300350, China
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31
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Ouyang W, Chen T, Shi Y, Tong L, Chen Y, Wang W, Yang J, Xue J. Physico-chemical processes. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2019; 91:1350-1377. [PMID: 31529571 DOI: 10.1002/wer.1231] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/05/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Abstract
The review scans research articles published in 2018 on physico-chemical processes for water and wastewater treatment. The paper includes eight sections, that is, membrane technology, granular filtration, flotation, adsorption, coagulation/flocculation, capacitive deionization, ion exchange, and oxidation. The membrane technology section further divides into six parts, including microfiltration, ultrafiltration, nanofiltration, reverse osmosis/forward osmosis, and membrane distillation. PRACTITIONER POINTS: Totally 266 articles on water and wastewater treatment have been scanned; The review is sectioned into 8 major parts; Membrane technology has drawn the widest attention from the research community.
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Affiliation(s)
- Weihang Ouyang
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Tianhao Chen
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Yihao Shi
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Liangyu Tong
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Yangyu Chen
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Weiwen Wang
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Jiajun Yang
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
| | - Jinkai Xue
- School of Civil Engineering, Sun Yat-Sen University, Guangzhou, Guangdong Province, China
- Environmental Systems Engineering, University of Regina, Saskatchewan, Canada
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32
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Zeng Z, Zheng P, Zhang M, Ghulam A. Performance and working mechanism of a novel anaerobic self-flotation reactor for treating wastewater with high suspended solids. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:26193-26202. [PMID: 31280446 DOI: 10.1007/s11356-019-05885-6] [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: 02/17/2019] [Accepted: 07/01/2019] [Indexed: 06/09/2023]
Abstract
The new design of internal flotation components and the use of biogas were employed to develop a novel anaerobic self-flotation (ASF) reactor. Compared with the upflow anaerobic sludge blanket (UASB) reactor, the removal efficiencies of total chemical oxygen demand (COD) and suspended solids (SS) of the ASF reactor were higher than 90% under high SS concentration and high volumetric organic loading rate (OLR). The biogas flotation, sludge bed retention, and effluent washout accounted for 60%, 30%, and 10% of SS mass, respectively, proving that the biogas flotation was the main mechanism of SS removal in the ASF reactor. Extracellular polymer substance, mainly consisting of polysaccharide (PS) and protein (PN), was found to promote the SS removal by biogas flotation via the scum formation at the ratio of 294.12 g-VS/g-PS and 103.09 g-VS/g-PN. The EPS yield was determined as 2.3 ± 0.6 g-PS/g-COD and 11.5 ± 2.6 g-PN/g-COD at the OLR of 60 kg/(m3 day). The biogas production was revealed to enhance the SS removal by providing flotation driving force and by decreasing the scum density. A model was established to describe the quantitative relationship between flotation scum and OLR. This work would shed light on the high SS wastewater treatment challenge of high-rate anaerobic processes by using biogas flotation.
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Affiliation(s)
- Zhuo Zeng
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Ping Zheng
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China.
| | - Meng Zhang
- Advanced Environmental Biotechnology Centre, Nanyang Environment & Water Research Institute, Nanyang Technological University, Cleantech Loop, Singapore, 637141, Singapore
| | - Abbas Ghulam
- Department of Chemical Engineering, University of Gujrat, Gujrat, 50700, Pakistan
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33
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Ge D, Yuan H, Xiao J, Zhu N. Insight into the enhanced sludge dewaterability by tannic acid conditioning and pH regulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 679:298-306. [PMID: 31085410 DOI: 10.1016/j.scitotenv.2019.05.060] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/05/2019] [Accepted: 05/05/2019] [Indexed: 06/09/2023]
Abstract
Tannic acid (TA), a phenolic compound, may be considered as a sludge conditioning agent on account of its ability to precipitate protein. In this study, the effectiveness of TA conditioning on enhancing waste activated sludge (WAS) dewatering was investigated at various pH values. The results indicated that with the conditioning of 0.15 mmol TA per gram of total solid (TS), the WAS dewaterability was affected distinctly by the pH regulation. The reductions of 86.8% capillary suction time (CST), 96.3% specific resistance of filtration (SRF), and 23.6% water content (Wc) of dewatered sludge cake were achieved at an optimal pH value of 4.0. Meanwhile, obvious alterations were observed in some aspects like supernatant viscosity, zeta potential, particle size and extracellular polymeric substances (EPS) polymers. Correlation analysis indicated that the proteins in slime EPS and loosely bound EPS dominantly governed sludge dewaterability. Fluorescence quenching analysis indicated that in the range of acidity, the increase of pH value afforded more binding sites of sludge EPS for TA. However, the removal of EPS protein depended on the combined effect of TA conditioning and pH regulation. The findings provided a novel approach and explanation of WAS dewaterability enhancement using organic additive conditioning and pH regulation.
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Affiliation(s)
- Dongdong Ge
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Haiping Yuan
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiamu Xiao
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Nanwen Zhu
- School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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34
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Flocculation kinetics and dewatering studies of quaternized cellulose derived from oil palm empty fruit bunches. KOREAN J CHEM ENG 2019. [DOI: 10.1007/s11814-019-0250-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Luo J, Zhu Y, Song A, Wang L, Shen C, Gui Z, Zhang Q, Cao J. Efficient short-chain fatty acids recovery from anaerobic fermentation of wine vinasse and waste activated sludge and the underlying mechanisms. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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