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Wu Y, Lu M, Liu X, Chen H, Deng Z, Fu Q, Wang D, Chen Y, Zhong Y. Insights into how poly aluminum chloride and poly ferric sulfate affect methane production from anaerobic digestion of waste activated sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 811:151413. [PMID: 34774636 DOI: 10.1016/j.scitotenv.2021.151413] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/30/2021] [Accepted: 10/30/2021] [Indexed: 06/13/2023]
Abstract
Poly aluminum chloride (PAC) and poly ferric sulfate (PFS) are widely used in wastewater treatment and sludge dewatering, resulting in their amounts being accumulated substantially in waste activated sludge (WAS). Till now, however, little information about their influence on WAS digestion is available. This work therefore aims to provide insights into how PAC and PFS affect sludge anaerobic digestion. The experimental results showed that PFS's inhibition to methane production was much severer than PAC, in control reactor (0 mg Al or Fe /g TSS), the maximum cumulative methane production was 152.99 ± 7.18 mL/g VSS, when flocculants concentration increased to 30 mg Al/g TSS or 30 mg Fe/g TSS, the yields decreased to 129.54 ± 6.18 mL/g VSS and 89.52 ± 4.82 mL/g VSS respectively. Mechanism explorations exhibited that protein in WAS could bond with flocculants, which would inhibit protein bioconversion. It was also observed that the apparent activation energy (AAE) of organic solubilisation of PAC and PFS-contained sludge were increased by 38.58% and 18.67% respectively. Meanwhile, compared to the PFS, PAC led to more serious suppression of hydrolysis and acidogenesis processes, with propionic acid used as substrate, PFS inhibit methanogenesis more severely than PAC. Illumina MiSeq sequencing analyses showed that the number of sulfate-reducing bacteria (SRB) enriched obviously in PFS reactor. The results revealed that although PFS reduced methane production more severely than PAC, the reduction was mainly enforced by the activity of SRB but not organic enmeshment. Furthermore, PAC severely suppresses acetotrophic methanogens but PFS depress hydrogenotrophic methanogenesis microorganism mainly. Additionally, malodor control and dewaterability enhancement of digested sludge can be realized with PAC existence. The finding obtained in this study would provide insights into the PFS or PAC-involved sludge anaerobic digestion system and might support the important implication for further manipulate WAS treatment in the future.
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Affiliation(s)
- Yanxin Wu
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - Min Lu
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Xuran Liu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Hongbo Chen
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Zhiyi Deng
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - Qizi Fu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China.
| | - Yaoning Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Yu Zhong
- Key Laboratory of Water Pollution Control Technology, Hunan Research Academy of Environmental Sciences, Changsha 410004, China
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Ping Q, Zhang Z, Dai X, Li Y. Novel CaO 2 beads used in the anaerobic fermentation of iron-rich sludge for simultaneous short-chain fatty acids and phosphorus recovery under ambient conditions. BIORESOURCE TECHNOLOGY 2021; 322:124553. [PMID: 33359566 DOI: 10.1016/j.biortech.2020.124553] [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: 11/03/2020] [Revised: 12/11/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
A novel composite CaO2 bead was prepared to improve total short-chain fatty acids (TSCFAs) production and phosphorus (P) recovery from iron-rich waste activated sludge (WAS) during ambient anaerobic fermentation. Results showed that CaO2 mass percentage of 5% and CaCl2:nylon66 = 1:1 (mass ratio) were the optimal prescription for the preparation of CaO2 beads with porous structure, loose morphology, and sustained-release of CaO2. The highest TSCFAs production (356 mg/g VSS) was observed and about 9% of P in sludge could be recovered on beads. The decrease of Fe-phosphate and Fe-oxides in the sludge were due to different mechanisms. Microbial community analyses showed that CaO2 beads effectively enriched dissimilatory iron-reducing bacteria (DIRB) and promoted iron-reduction related genes. After fermentation, the P-rich beads are easy to separate from sludge for further P recovery, and the supernatant carrying abundant acetate and Fe2+ can be returned to the wastewater treatment line to improve nutrient removal.
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Affiliation(s)
- Qian Ping
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Zhipeng Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yongmei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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Ping Q, Lu X, Li Y, Mannina G. Effect of complexing agents on phosphorus release from chemical-enhanced phosphorus removal sludge during anaerobic fermentation. BIORESOURCE TECHNOLOGY 2020; 301:122745. [PMID: 31954968 DOI: 10.1016/j.biortech.2020.122745] [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: 10/31/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 06/10/2023]
Abstract
Phosphorus (P) release from sludge containing phosphate precipitates (FePs or AlPs) as well as the anaerobic performance with the addition of complexing agents (citric, tartaric and EDTA) during ambient anaerobic fermentation process were investigated. Results showed that citrate addition was the most effective method to enhance P release from inorganic phosphate by chelation and promote volatile fatty acids (VFAs) production simultaneously during anaerobic fermentation. Equimolar citrate addition with chemical precipitates was the optimal dosage. Microbial analysis revealed that EDTA has the strongest inhibitory effect on microbial activity and community structure, while citrate was more effective in enhancing important acidifying microorganisms than tartrate and EDTA. Therefore, citrate addition can be regarded as an alternative and promising method to recover P and carbon source from sludge containing chemical precipitates. These important discoveries will help to enrich P recovery path from sludge produced in the chemical-enhanced P removal treatment processes.
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Affiliation(s)
- Qian Ping
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiao Lu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Yongmei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Giorgio Mannina
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Engineering Department, Palermo University, Viale delle Scienze, ed. 8, 90128 Palermo, Italy
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The Effects of Aluminium- and Ferric-Based Chemical Phosphorus Removal on Activated Sludge Digestibility and Dewaterability. Processes (Basel) 2019. [DOI: 10.3390/pr7040228] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The uses of Al3+ and Fe3+ salts in chemical phosphorus removal (CPR) in activated sludge plants have increased considerably in recent years and their full impacts on downstream processes such as dewaterability and digestibility are not fully understood. In this research, the effects of CPR on sludge digestibility and dewaterability were investigated in laboratory-scale experiments using sludge samples from a full-scale wastewater treatment plant. The results of the digestibility tests showed a 21% and 36% reduction in the biogas volume generated during anaerobic digestion of surplus activated sludge at 0.1 g/L doses of Al3+ and Fe3+ salts, respectively. This demonstrates that Al3+ dosing for CPR has less of a reduction effect compared with Fe3+ salts on biogas generation during anaerobic digestion of sludge. The dewaterability tests showed that primary sludge dewaterability was improved by up to 25% by Fe3+ and 16% by Al3+, while that of surplus activated sludge was reduced by 64% and 73%, respectively, at a metal salt dose of 50 mg/L. Consequently, a pre-precipitation process during CPR where phosphorus is removed in the primary tank would, therefore, enhance sludge dewaterability.
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Eduok S, Ferguson R, Jefferson B, Villa R, Coulon F. Aged-engineered nanoparticles effect on sludge anaerobic digestion performance and associated microbial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 609:232-241. [PMID: 28746890 DOI: 10.1016/j.scitotenv.2017.07.178] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 06/07/2023]
Abstract
To investigate the potential effect of aged engineered nanoparticles (a-ENPs) on sludge digestion performance, 150L pilot anaerobic digesters (AD) were fed with a blend of primary and waste activated sludge spiked either with a mixture of silver oxide, titanium dioxide and zinc oxide or a mixture of their equivalent bulk metal salts to achieve a target concentration of 250, 2000, and 2800mgkg-1 dry weight, respectively. Volatile fatty acids (VFA) were 1.2 times higher in the spiked digesters and significantly different (p=0.05) from the control conditions. Specifically, isovaleric acid concentration was 2 times lower in the control digester compared to the spiked digesters, whereas hydrogen sulfide was 2 times lower in the ENPs spiked digester indicating inhibitory effect on sulfate reducing microorganisms. Based on the ether-linked isoprenoids concentration, the total abundance of methanogens was 1.4 times lower in the ENPs spiked digester than in the control and metal salt spiked digesters. Pyrosequencing indicated 80% decrease in abundance and diversity of methanogens in ENPs spiked digester compared to the control digester. Methanosarcina acetivorans and Methanosarcina barkeri were identified as nano-tolerant as their relative abundance increased by a factor of 6 and 11, respectively, compared to the other digesters. The results further provide compelling evidence on the resilience of Fusobacteria, Actinobacteria and the Trojan horse-like effect of ENPs which offered a competitive advantage to some organisms while reducing microbial abundance and diversity.
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Affiliation(s)
- Samuel Eduok
- Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, UK
| | - Robert Ferguson
- Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, UK
| | - Bruce Jefferson
- Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, UK
| | - Raffaella Villa
- Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, UK
| | - Frédéric Coulon
- Cranfield University, School of Water, Energy and Environment, Cranfield MK43 0AL, UK.
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Smith JA, Carliell-Marquet CM. A novel laboratory method to determine the biogas potential of iron-dosed activated sludge. BIORESOURCE TECHNOLOGY 2009; 100:1767-1774. [PMID: 19022664 DOI: 10.1016/j.biortech.2008.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Revised: 09/29/2008] [Accepted: 10/04/2008] [Indexed: 05/27/2023]
Abstract
Sludge biogas potential is often reduced by iron-dosing, the extent of the reduction being related to the nature of the sludge and the dosing process. The aim of this research was to develop a rapid laboratory method to measure the impact of iron-dosing on the biogas potential of activated sludge, taking into account the mechanisms that may be decreasing biogas yield. To validate the method, sequential extraction (SE) was used to fractionate iron and phosphorus in the sludge before and after iron-dosing. The laboratory-dosing regime increased total iron and phosphorus in the sludge but decreased their bioavailability, producing sludge with a similar inorganic composition to full-scale chemical P removal (CPR) sludge. Laboratory-dosed sludge produced 12-20% less biogas and 9-21% less methane when anaerobically digested, in comparison to the same undosed sludge. This method should help water companies and academics to more closely simulate iron-dosing in the laboratory.
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Smith JA, Carliell-Marquet CM. The digestibility of iron-dosed activated sludge. BIORESOURCE TECHNOLOGY 2008; 99:8585-8592. [PMID: 18485699 DOI: 10.1016/j.biortech.2008.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 04/01/2008] [Accepted: 04/03/2008] [Indexed: 05/26/2023]
Abstract
The impact of chemical phosphorus (P) removal on anaerobic digestion (AD) has long been debated, possibly because there is no general consensus of the definition of impaired AD, but also because of the different assessment methods used. This research surveyed 12 wastewater treatment plants to compare the relative digestibility of iron-dosed with undosed activated sludge during two batch test trials. Results showed that iron-dosed sludge negatively impacted AD by reducing the volume of biogas (12%) and methane (5.5%) produced from the same amount of volatile solids fed. Possible reasons for reduced biogas production include lower levels of bioavailable P and iron in iron-dosed sludge, which may hinder the ability of micro-organisms to metabolise organic substrate.
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Affiliation(s)
- Jennifer A Smith
- Centre for Water Science, Cranfield University, Cranfield MK43 0AL, UK.
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