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Chen H, Ye Q, Wang X, Sheng J, Yu X, Zhao S, Zou X, Zhang W, Xue G. Applying sludge hydrolysate as a carbon source for biological denitrification after composition optimization via red soil filtration. WATER RESEARCH 2024; 249:120909. [PMID: 38006788 DOI: 10.1016/j.watres.2023.120909] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/12/2023] [Accepted: 11/21/2023] [Indexed: 11/27/2023]
Abstract
Sludge hydrolysate, the byproduct generated during sludge hydrothermal treatment (HT), is a potential carbon source for biological denitrification. However, the refractory organic matters and the nutrient substances are unfavorable to the nitrogen removal. In this study, effects of HT conditions on the hydrolysate properties, and the hydrolysate compositions optimization via red soil (RS) filtration were investigated. At HT temperature of 160-220 °C and reaction time of 1-4 h, the highest dissolution rate of organics from sludge to hydrolysate achieved 70.1 %, while the acetic acid dominated volatile fatty acids (VFAs) was no more than 5.0 % of the total organic matter content. The NH4+-N and dissolved organic nitrogen (DON) were the main nitrogen species in hydrolysate. When the hydrolysate was filtered by RS, the high molecular weight organic matters, DON, NH4+ and PO43- were effectively retained by RS, while VFAs and polysaccharide favorable for denitrification were kept in the filtrate. When providing same COD as the carbon source, the filtrate group (Fi-Group) introduced lower concentrations of TN and humic substances but higher content of VFAs. This resulted in TN removal rate (57.0 %) and denitrification efficiency (93.6 %) in Fi-Group higher than those in hydrolysate group (Hy-Group), 39.4 % and 83.7 %, respectively. It is noticeable that both Hy- and Fi- Groups up-regulated most of denitrification functional genes, and increased the richness and diversity of denitrifying bacteria. Also, more denitrifying bacteria genera appeared, and their relative abundance increased significantly from 3.31 % in Control to 21.15 % in Hy- Group and 31.31 % in Fi-Group. This indicates that the filtrate is a more suitable carbon source for denitrification than hydrolysate. Moreover, the pH rose from 4.6 ± 0.14 to 6.5 ± 0.05, and the organic carbon, TN, TP and cation exchange capacity (CEC) of RS increased as well after being filtered, implying that the trapped compounds may have the potential to improve soil quality. This study provides a new insight for hydrolysate application according to its composition characteristics, and helps make the most use of wasted sludge.
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Affiliation(s)
- Hong Chen
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China; Key Lab of Eco-restoration of Regional Contaminated Environment (Shenyang University), Ministry of Education, Shenyang, 110044, PR China; School of Life Science, Jinggangshan University, 28 Xueyuan Road, Ji'an, 343009, PR China
| | - Qinhui Ye
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China
| | - Xiulan Wang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China
| | - Jun Sheng
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China
| | - Xin Yu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China
| | - Shiyi Zhao
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China
| | - Xiaoming Zou
- School of Life Science, Jinggangshan University, 28 Xueyuan Road, Ji'an, 343009, PR China.
| | - Weiwei Zhang
- Key Lab of Eco-restoration of Regional Contaminated Environment (Shenyang University), Ministry of Education, Shenyang, 110044, PR China
| | - Gang Xue
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai, 201620, PR China
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Wang S, Zhu XM, Hong SD, Zheng SJ, Wang YB, Huang XC, Tian YC, Li WT, Lu YZ, Wu J, Zeng RJ, Dai K, Zhang F. Unveiling the Occurrence and Non-Negligible Role of Amino Sugars in Waste Activated Sludge Fermentation by an Enriched Chitin-Degradation Consortium. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:1966-1975. [PMID: 38153028 DOI: 10.1021/acs.est.3c09302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Polysaccharides in extracellular polymeric substances (EPS) can form a hybrid matrix network with proteins, impeding waste-activated sludge (WAS) fermentation. Amino sugars, such as N-acetyl-d-glucosamine (GlcNAc) polymers and sialic acid, are the non-negligible components in the EPS of aerobic granules or biofilm. However, the occurrence of amino sugars in WAS and their degradation remains unclear. Thus, amino sugars (∼6.0%) in WAS were revealed, and the genera of Lactococcus and Zoogloea were identified for the first time. Chitin was used as the substrate to enrich a chitin-degrading consortium (CDC). The COD balances for methane production ranged from 83.3 and 95.1%. Chitin was gradually converted to oligosaccharides and GlcNAc after dosing with the extracellular enzyme. After doing enriched CDC in WAS, the final methane production markedly increased to 60.4 ± 0.6 mL, reflecting an increase of ∼62%. Four model substrates of amino sugars (GlcNAc and sialic acid) and polysaccharides (cellulose and dextran) could be used by CDC. Treponema (34.3%) was identified as the core bacterium via excreting chitinases (EC 3.2.1.14) and N-acetyl-glucosaminidases (EC 3.2.1.52), especially the genetic abundance of chitinases in CDC was 2.5 times higher than that of WAS. Thus, this study provides an elegant method for the utilization of amino sugar-enriched organics.
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Affiliation(s)
- Shuai Wang
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Xiao-Mei Zhu
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Si-Di Hong
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Si-Jie Zheng
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yi-Bo Wang
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Xing-Chen Huang
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Ye-Chao Tian
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Wen-Tao Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Yong-Ze Lu
- School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Jianrong Wu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Raymond Jianxiong Zeng
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Kun Dai
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Fang Zhang
- Center of Wastewater Resource Recovery, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
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Liu K, Lv L, Li W, Wang X, Han M, Ren Z, Gao W, Wang P, Liu X, Sun L, Zhang G. Micro-aeration and leachate recirculation for the acceleration of landfill stabilization: Enhanced hydrolytic acidification by facultative bacteria. BIORESOURCE TECHNOLOGY 2023; 387:129615. [PMID: 37544542 DOI: 10.1016/j.biortech.2023.129615] [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: 06/14/2023] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/08/2023]
Abstract
The long duration of landfill stabilization is one of the challenges faced by municipalities. In this paper, a combination of micro-aeration and leachate recirculation is used to achieve rapid degradation of organic matter in landfill waste. The results showed that the content of volatile fatty acids (VFAs) in the hydrolysis phase increased significantly and could enter the methanogenic phase quickly. Until the end of the landfill, the removal rates of chemical oxygen demand (COD), total phosphorus (TP) and ammonia nitrogen (NH4+-N) by micro-aeration and leachate recirculation reached 80.17 %, 48.30 % and 48.56 %, respectively, and the organic matter degradation rate reached 50 %. Micro-aeration and leachate recirculation enhanced the abundance of facultative hydrolytic bacteria such as Rummeliibacillus and Bacillus and the oxygen tolerance of Methanobrevibacter and Methanoculleus. Micro-aeration and leachate recirculation improved the organic matter degradation efficiency of landfill waste by promoting the growth of functional microorganisms.
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Affiliation(s)
- Kaili Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Longyi Lv
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China.
| | - Weiguang Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China
| | - Xinyuan Wang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Muda Han
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Zhijun Ren
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Wenfang Gao
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Pengfei Wang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Xiaoyang Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Li Sun
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Guangming Zhang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China.
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Liu K, Lv L, Li W, Ren Z, Wang P, Liu X, Gao W, Sun L, Zhang G. A comprehensive review on food waste anaerobic co-digestion: Research progress and tendencies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 878:163155. [PMID: 37001653 DOI: 10.1016/j.scitotenv.2023.163155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/22/2023] [Accepted: 03/26/2023] [Indexed: 05/13/2023]
Abstract
Food waste (FW) anaerobic digestion systems are prone to imbalance during long-term operation, and the imbalance mechanism is complex. Anaerobic co-digestion (AcoD) of FW and other substrates can overcome the performance limitations of single digestion, allowing for the mutual use of multiple wastes and resource recovery. Research on the AcoD of FW has been widely conducted and successfully applied to a practical engineering scale. Therefore, this review describes the research progress of AcoD of FW with other substrates. By analyzing the problems and challenges faced by AcoD of FW, the synergistic effects and influencing factors of different biomass wastes are discussed, and improvement strategies to improve the performance of AcoD of FW are summarized from different reaction stages of anaerobic digestion. By combing the research progress of AcoD of FW, it provides a reference for the optimization and improvement of the performance of the co-digestion system.
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Affiliation(s)
- Kaili Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Longyi Lv
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China.
| | - Weiguang Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, PR China
| | - Zhijun Ren
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Pengfei Wang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Xiaoyang Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Wenfang Gao
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Li Sun
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China
| | - Guangming Zhang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, PR China.
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Pavez-Jara JA, van Lier JB, de Kreuk MK. Accumulating ammoniacal nitrogen instead of melanoidins determines the anaerobic digestibility of thermally hydrolyzed waste activated sludge. CHEMOSPHERE 2023; 332:138896. [PMID: 37169092 DOI: 10.1016/j.chemosphere.2023.138896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 05/04/2023] [Accepted: 05/07/2023] [Indexed: 05/13/2023]
Abstract
Full-scale thermal hydrolysis processes (THP) showed an increase in nutrients release and formation of melanoidins, which are considered to negatively impact methanogenesis during mesophilic anaerobic digestion (AD). In this research, fractionation of THP-sludge was performed to elucidate the distribution of nutrients and the formed melanoidins over the liquid and solid sludge matrix. Degradation of the different fractions in subsequent AD was assessed, and the results were compared with non-pre-treated waste activated sludge (WAS). Results showed that the THP-formed soluble melanoidins were partially biodegradable under AD, especially the fraction with molecular weight under 1.1 kDa, which was related to protein-like substances. The use of THP in WAS increased the non-biodegradable soluble chemical oxygen demand (sCOD) after AD, from 1.1% to 4.9% of the total COD. The total ammoniacal nitrogen (TAN) concentration only slightly increased during THP without AD. However, after AD, TAN released was 34% higher in the THP-treated WAS compared to non-treated WAS, i.e., 36.7 ± 0.7 compared to 27.4 ± 0.4 mgTANreleased/gCODsubstrate, respectively. Results from modified specific methanogenic activities (mSMAs) tests showed that the organics solubilised during THP, were not inhibitory for acetotrophic methanogens. However, after AD of THP-treated sludge and WAS, the mSMA showed that all analysed samples presented strong inhibition on methanogenesis due to the presence of TAN and associated free ammonia nitrogen (FAN). In specific methanogenic activities (SMAs) tests with incremental concentration of TAN/FAN and melanoidins, TAN/FAN induced strong inhibition on methanogens, halving the SMA at around 2.5 gTAN/L and 100 mgFAN/L. Conversely, melanoidins did not show inhibition on the methanogens. Our present results revealed that when applying THP-AD in full-scale, the increase in TAN/FAN remarkably had a greater impact on AD than the formation of melanoidins.
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Affiliation(s)
- Javier A Pavez-Jara
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands.
| | - Jules B van Lier
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands.
| | - Merle K de Kreuk
- Department of Water Management, Delft University of Technology, Building 23 Stevinweg 1, 2628, Delft, the Netherlands.
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Hu ZY, Lin YP, Wang QT, Zhang YX, Tang J, Hong SD, Dai K, Wang S, Lu YZ, van Loosdrecht MCM, Wu J, Zeng RJ, Zhang F. Identification and degradation of structural extracellular polymeric substances in waste activated sludge via a polygalacturonate-degrading consortium. WATER RESEARCH 2023; 233:119800. [PMID: 36868117 DOI: 10.1016/j.watres.2023.119800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/22/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
By maintaining the cell integrity of waste activated sludge (WAS), structural extracellular polymeric substances (St-EPS) resist WAS anaerobic fermentation. This study investigates the occurrence of polygalacturonate in WAS St-EPS by combining chemical and metagenomic analyses that identify ∼22% of the bacteria, including Ferruginibacter and Zoogloea, that are associated with polygalacturonate production using the key enzyme EC 5.1.3.6. A highly active polygalacturonate-degrading consortium (GDC) was enriched and the potential of this GDC for degrading St-EPS and promoting methane production from WAS was investigated. The percentage of St-EPS degradation increased from 47.6% to 85.2% after inoculation with the GDC. Methane production was also increased by up to 2.3 times over a control group, with WAS destruction increasing from 11.5% to 28.4%. Zeta potential and rheological behavior confirmed the positive effect which GDC has on WAS fermentation. The major genus in the GDC was identified as Clostridium (17.1%). Extracellular pectate lyases (EC 4.2.2.2 and 4.2.2.9), excluding polygalacturonase (EC 3.2.1.15), were observed in the metagenome of the GDC and most likely play a core role in St-EPS hydrolysis. Dosing with GDC provides a good biological method for St-EPS degradation and thereby enhances the conversion of WAS to methane.
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Affiliation(s)
- Zhi-Yi Hu
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yi-Peng Lin
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qing-Ting Wang
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yi-Xin Zhang
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jie Tang
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Si-Di Hong
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Kun Dai
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shuai Wang
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yong-Ze Lu
- School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands
| | - Jianrong Wu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Raymond Jianxiong Zeng
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Fang Zhang
- Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Xiong YS, Li MX, Jia R, Zhou LS, Fan BH, Tang JY, Gai L, Li W, Lu HQ, Li K. Polyethyleneimine/polydopamine-functionalized self-floating microspheres for caramel adsorption: Interactions and phenomenological mass transfer kinetics. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Li Z, Chen H. Elucidating the role of solids content in low-temperature thermal hydrolysis and anaerobic digestion of sewage sludge. BIORESOURCE TECHNOLOGY 2022; 362:127859. [PMID: 36037837 DOI: 10.1016/j.biortech.2022.127859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
The role of total solids content in low-temperature thermal hydrolysis and anaerobic digestion of sewage sludge was investigated. Increasing total solids from 2% to 6% improved thermal hydrolysis and anaerobic digestion performance, while increasing it further to 12% decreased methane production. Maximum sludge solubility (22.9% ± 0.6%) and methane production (320 ± 7 mL/g volatile solids) were achieved at 6% solids. The increase in solids content from 2% to 6% improved heating efficiency and volatile fraction content, which facilitated sludge solubilization and enrichment of methanogens. However, further increases in solids content resulted in a stable floc structure with excess ammonia nitrogen and volatile fatty acids, which limited the release of substrates and reduced the abundance of acidifying bacteria and methanogens, ultimately leading to reduced methane production. An in-depth understanding of the role of solids content opens up new avenues for improved low-temperature thermal hydrolysis of sludge.
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Affiliation(s)
- Zeyu Li
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Hongbo Chen
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
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Hydrothermal Pretreatment of Wheat Straw—Evaluating the Effect of Substrate Disintegration on the Digestibility in Anaerobic Digestion. Processes (Basel) 2022. [DOI: 10.3390/pr10061048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The increasing demand for renewable energy sources and demand-oriented electricity provision makes anaerobic digestion (AD) one of the most promising technologies. In addition to energy crops, the use of lignocellulosic residual and waste materials from agriculture is becoming increasingly important. However, AD of such feedstocks is often associated with difficulties due to the high content of lignocellulose and its microbial persistence. In the present work, the effect of hydrothermal pretreatment (HTP) on the digestibility of wheat straw is investigated and evaluated. Under different HTP temperatures (160–180 °C) and retention times (15–45 min), a significant increase in biomethane potential (BMP) can be observed in all cases. The highest BMP (309.64 mL CH4 g−1 volatile solid (VS) is achieved after pretreatment at 160 °C for 45 min, which corresponds to an increase of 19% of untreated wheat straw. The results of a multiple linear regression model show that the solubilization of organic materials is influenced by temperature and time. Furthermore, using two different first-order kinetic models, an enhancement of AD rate during hydrolysis due to pretreatment is observed. However, the increasing intensity of pretreatment conditions is accompanied by a decreasing trend in the conversion of intermediates to methane.
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