1
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Song S, Jiang M, Liu H, Dai X, Wang P. Application of the biogas residue of anaerobic co-digestion of gentamicin mycelial residues and wheat straw as soil amendment: Focus on nutrients supply, soil enzyme activities and antibiotic resistance genes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 335:117512. [PMID: 36827805 DOI: 10.1016/j.jenvman.2023.117512] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/11/2023] [Indexed: 06/18/2023]
Abstract
Land utilization of the biogas residue (BR) produced by anaerobic co-digestion of gentamicin mycelial residues (GMRs) and wheat straw is a promising method to achieve the deep recycling of GMRs. This study evaluated the feasibility and efficacy of application of using BR as a soil amendment by using a pot experiment. Results indicated that BR could improve the soil fertility better than commercial chicken manure fertilizer (CMF) in terms of the soil enzyme activities and nutrients supply. Random Forest (RF) model was applied to predict soil enzyme activities and identify key influencing factors. Combining the Random Forest (RF) model with the Three-dimensional Excitation-emission Matrix and Parallel Factor (3D-EEM-PARAFAC) analysis, revealing that humic-like substances provided by BR protected soil enzymes, thus improving soil fertility. Furthermore, gentamicin and antibiotic resistance genes (ARGs)/mobile genetic elements (MEGs) introduced by BR decreased greatly after cultivation, implying a low risk of antimicrobial resistance. This study suggested that reasonable application of BR could improve soil nutrients supply, soil enzyme activity and control antimicrobial resistance risk.
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Affiliation(s)
- Siqi Song
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Mingye Jiang
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Huiling Liu
- School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Peng Wang
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China.
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2
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Ziyao S, Xiaorong Z, Zaiqian W, Yihan H, Yimin L, Xuquan H. Comprehensive effects of grain-size modification of electrolytic manganese residue on deep dehydration performance and microstructure of sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116793. [PMID: 36455369 DOI: 10.1016/j.jenvman.2022.116793] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/31/2022] [Accepted: 11/12/2022] [Indexed: 06/17/2023]
Abstract
As the by-product accompanied by sewage treatment, sludge has complex composition and high moisture content, therefore, its reutilization and disposal are still a challenge. In this paper, five kinds of quartz sand conditioners with different particle sizes (denoted as QS1, QS2, QS3, QS4 and QS5, respectively) were used to explore the effect of particle size distribution of conditioners on sludge dewatering performance. The moisture content, capillary suction time (CST), time to filter (TTF), specific resistance of filtration (SRF), particle size distribution curve, pore distribution law, scanning electron microscopy, isothermal adsorption-desorption curve and extracellular polymeric substances distribution were employed to characterize the modified sludge and explore the improvement mechanism. The results show that the particle size distribution of the conditioner significantly affects the efficiency of sludge dewatering. The wt% of sludge regulated with QS1 (QS1-S) could be reduced to 52%, and its CST value, TTF value and SRF value is 57.93 s, 278 s and 1.84 × 108 s2 g-1, respectively. The conjecture about the effect of difference of particle size distribution on sludge dewatering performance was verified with the original Electrolytic Manganese Residue (EMR) and the grain-size modified Electrolytic Manganese Residue (EMR6). Compared with those of the EMR-conditioned sludge, the CST, TTF and SRF of EMR6-conditioned sludge was decreased by 8.7%, 22.3% and 11.2%, respectively. According to analysis of surface microstructure, the surface of the sludge cake modified with QS1 is rough and sparse with rich pore structure. Compared with those of the undisturbed sludge (A0), the pore volume and specific surface area of the sludge modified with QS1 was increased by 61.65% and 38.62%, respectively. After grain-size modification, the dehydration effect of EMR6 (D10 4.25 μm, D50 19.65 μm, D90 73.26 μm) was significantly enhanced, and the D10, D50 and D90 value was close to that of QS1. It can be concluded that the particle size of QS1 (D10 3.27 μm, D50 15.66 μm, and D90 62.23 μm) can improve the dewatering performance of sludge by shearing the sludge particles to change the original sludge particle size distribution and improving the blockage of sludge dewatering channels.
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Affiliation(s)
- Shi Ziyao
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, China
| | - Zhao Xiaorong
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, China; Hubei Province Enterprise-college Cooperation Innovation Center for Comprehensive Utilization of Phosphogypsum, Yichang, 443002, China
| | - Wang Zaiqian
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, China
| | - Huang Yihan
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, China
| | - Luo Yimin
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, China
| | - Huang Xuquan
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, Yichang, 443002, China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, 443002, China; Hubei Province Enterprise-college Cooperation Innovation Center for Comprehensive Utilization of Phosphogypsum, Yichang, 443002, China.
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3
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Lin F, Li B. Changes of network structure and water distribution in sludge with the stratified extraction of extracellular polymeric substances. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:48648-48660. [PMID: 35195865 DOI: 10.1007/s11356-022-19075-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
The water in sludge is trapped within the extracellular polymeric substance (EPS) with gelatinous structure, greatly challenging the sludge deep dewatering. In this paper, the effect of the EPS viscoelasticity and the structural characteristics of sludge flocs on water distribution was revealed to provide a highly efficient approach in research on sludge dewatering. After biological, and physical method conditioning, the change of viscoelasticity and sludge network structure before/after EPS extraction was comprehensively explored, together with the sludge dewaterability and water distribution. The results suggested the proportion of capillary water and adsorption water carried in soluble EPS (S-EPS) was 59.17% and 40.83%, and that in tightly bound EPS (TB-EPS) was 54.77% and 45.23%, respectively. By contrast, the capillary water in loosely bound EPS (LB-EPS) accounted for as high as 99.99%. In comparison with raw sludge, adsorption water proportion in TB-EPS and S-EPS was reduced after lysozyme (LZM) or freezing-thaw conditioning, which was ascribed to reduction of EPS viscosity and the weakness of water adsorption capacity. Additionally, the sludge yield stress (τy) value first reduced and then increased with the extraction of EPS. Meanwhile, the consistency coefficient (k) also decreased from 4.23 Pa·sn to 0.006 Pa·sn and then slightly increased after LZM conditioning. This observation indicated the sludge system became sensitive to shearing, and its network structural strength as well as colloid elasticity first weakened and then slightly strengthened. In addition, after LZM or freezing-thaw conditioning, the sludge particle size significantly increased after TB-EPS extraction, while the sludge particle more easily absorbed water molecules, thereby increasing adsorption water and capillary water within the sludge flocs. This phenomenon also resulted in an increasing trend of capillary suction time (CST) after TB-EPS extraction, indicating the deterioration of sludge filtration performance.
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Affiliation(s)
- Feng Lin
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Bingyun Li
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China.
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4
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Chen R, Sheng Q, Chen S, Dai X, Dong B. The three-stage effect of hydrothermal treatment on sludge physical-chemical properties: Evolution of polymeric substances and their interaction with physicochemical properties. WATER RESEARCH 2022; 211:118043. [PMID: 35026549 DOI: 10.1016/j.watres.2022.118043] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 01/02/2022] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Hydrothermal treatment (HT) is effective for the deep dewatering of sewage sludge (SS); however, the effective temperature generally exceeds 180 ℃, resulting in the production of refractory compounds in the sludge filtrates. To explore a new process based on HT, achieving ideal dehydration efficiency at lower temperatures, it is essential to identify the key sludge dewatering mechanism under different HT stages. In this study, the relationship between the properties of sludge polymeric substances (components and molecular structures) and the physical-chemical properties of sludge flocs during HT (120-260 ℃) was investigated. The results indicated that the SS surface hydrophilicity/hydrophobicity was mainly responsible for sludge dewaterability in the solubilization (120 ℃) and hydrolyzation stages (140-180 ℃), while the mechanically bound water and capillary force were the main limiting factors of sludge dewaterability during the carbonization stage (200-260 ℃). Moreover, in the solubilization stage (120 ℃), a plenty of high-Mw (Mw > 70 kDa) polymeric substances with numerous hydrophilic functional groups and a compact structure were released from the intracellular region to the outer layer, which improved the hydrophilicity of sludge floc surface and deteriorated the sludge dewaterability. With the hydrolysis of the polymeric substances (140-180 ℃, hydrolyzation stage), the destruction of proteins secondary structures and peptide chains exposed more hydrophobic groups, resulting in the release of bound water and improvement of sludge dewaterability. At HT temperatures of 200-260 ℃ (carbonization stage), dehydration and amine aldehyde condensation occurred, benefiting the formation of fixed carbon and smooth morphology structure of SS, reducing the capillary force-induced water-holding capacity of sludge flocs. The establishment of the three-stage influencing theory and the identification of key influencing factors are conducive to the further regulation and upgrading of HT.
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Affiliation(s)
- Renjie Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Qian Sheng
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Sisi Chen
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Bin Dong
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; YANGTZE Eco-Environment Engineering Research Center, China Three Gorges, Corporation, Beijing 100038, PR China.
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5
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Ning Z, Xu B, Zhong W, Liu C, Qin X, Feng W, Zhu L. Preparation of phosphoric acid modified antibiotic mycelial residues biochar: Loading of nano zero-valent iron and promotion on biogas production. BIORESOURCE TECHNOLOGY 2022; 348:126801. [PMID: 35124216 DOI: 10.1016/j.biortech.2022.126801] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Antibiotic mycelial residues (AMRs), as recyclable hazardous waste, can realize efficient utilization by reasonable treatment. To solve the problems of undeveloped pore structure and low specific surface area existed in AMR biochar, this study first modified biochar by phosphoric acid (H3PO4) to prepare PBC (H3PO4-modified biochar). Then, PBC was used as carrier to load nano zero-valent iron (nZVI) for preparation of nZVI/PBC. Finally, the biochar materials were used to promote anaerobic digestion (AD) of corn straw. The results showed that H3PO4-modification can effectively improve the specific surface area, pore structure, and electron donating capacity of AMRs biochar. The using of PBC as carrier to load nZVI attenuated the agglomeration of nZVI particles. Both PBC and nZVI/PBC improved the AD process, with biogas yield enhanced by 29.63% and 29.26%, respectively. The nZVI/PBC exhibited higher ability in maintaining the stability of AD system and promotion of fiber degradation than PBC.
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Affiliation(s)
- Zhifang Ning
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China
| | - Bin Xu
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China
| | - Weizhang Zhong
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China.
| | - Chun Liu
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China
| | - Xue Qin
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China
| | - Weibo Feng
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China
| | - Lin Zhu
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China
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6
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Cai C, Hua Y, Liu H, Dai X. A new approach to recycling cephalosporin fermentation residue into plant biostimulants. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125393. [PMID: 33609861 DOI: 10.1016/j.jhazmat.2021.125393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/11/2021] [Accepted: 02/09/2021] [Indexed: 06/12/2023]
Abstract
Cephalosporin fermentation residue (CFR), a byproduct of the pharmaceutical industry, mainly contains the mycelial biomass and unutilized culture medium, which can be reused as a high-quality protein source. This study first reports the recycling CFR into plant biostimulants using partial acid hydrolysis. Temperature, reaction time and ratio of hydrochloric acid/dry matter (H/S) were optimized for yielding both free amino acid and low molecular weight fraction based on response surface methodology. The crude protein concentration of CFR is 55%, with glutamic acid being the dominant amino acid (12.5%). Two favorable hydrolysis conditions were obtained: (1) 140 °C, 10.7 h, 17 H/S for maximizing the amino acid yield of 45.5 g/100 g CFR dw and (2) 100 °C, 10.7 h, 19 H/S for maximizing the low molecular weight fraction of 28.2%. The CFR-derived biostimulants obtained from two optimum conditions possessed two biostimulant modes of action: plant growth promotors/inhibitors and stress alleviators. However, they showed the differences in aminograms and profiles of low molecular weight compounds. Neither residual cephalosporin C nor its byproduct was detected in the CFR-derived biostimulants, suggesting that partial acid hydrolysis appears capable of recycling CFR into plant biostimulant safely.
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Affiliation(s)
- Chen Cai
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yu Hua
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Huiling Liu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
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7
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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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Chen Y, Du L, Li S, Song W, Jensen PA, Lin W. Pyrolysis of antibiotic mycelial dreg and characterization of obtained gas, liquid and biochar. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123826. [PMID: 33254808 DOI: 10.1016/j.jhazmat.2020.123826] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/12/2020] [Accepted: 08/22/2020] [Indexed: 06/12/2023]
Abstract
The disposal and utilization of antibiotic mycelial dreg (AMD), which has been identified as a hazardous waste in China, are a serious concern because of the residual antibiotic and huge annual output. Pyrolysis is a promising technology to treat AMD. However, the pyrolysis of AMD is not studied in an adequate degree, particularly no attention has been paid to the release and distribution of the phosphorus in AMD during pyrolysis. Therefore, the present work studied the pyrolysis of AMD more comprehensively. The influence of pyrolysis temperature on product yields and characteristics, together with the release and distribution of nitrogen and phosphorus, and the antibiotic residue in products, were investigated. The results suggested that residual antibiotic was eliminated after pyrolysis. Nitrogen was mainly contained in the biochar and liquid products, while phosphorus was mainly retained in the biochar. Liquid products were characterized by abundant oxygen and nitrogen-containing compounds, while biochar was featured of both abundant nitrogen and inorganic phosphate groups. Pyrolysis temperature showed a significant effect on product yields and characteristics, and a low pyrolysis temperature is recommended considering the recycling of nitrogen and phosphorus. The disposal of AMD through pyrolysis conforms to the principles of AMD disposal.
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Affiliation(s)
- Yuan Chen
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190, Beijing, China; Sino-Danish College, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Lin Du
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190, Beijing, China
| | - Songgeng Li
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190, Beijing, China; Sino-Danish College, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Wenli Song
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190, Beijing, China; Sino-Danish College, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Peter Arendt Jensen
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Weigang Lin
- State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190, Beijing, China; Sino-Danish College, University of Chinese Academy of Sciences, 100049, Beijing, China; Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
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9
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Song S, Jiang M, Yao J, Liu H, Dai X, Wang G. Alkaline-thermal pretreatment of spectinomycin mycelial residues: Insights on anaerobic biodegradability and the fate of antibiotic resistance genes. CHEMOSPHERE 2020; 261:127821. [PMID: 32750621 DOI: 10.1016/j.chemosphere.2020.127821] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Alkaline-thermal (AT) pretreatment is an economical and efficient pretreatment method to improve anaerobic biodegradability of biowaste. This study investigated the effect of AT pretreatment of spectinomycin mycelial residues (SMRs) for promoting anaerobic biodegradability along with the reduction of antibiotic resistance genes (ARGs), and thus obtained the optimal conditions of AT pretreatment. Biomethane potential (BMP) test was conducted to evaluate the anaerobic biodegradability of untreated and pretreated SMRs, and the fate of ARGs was tracked by quantitative polymerase chain reaction. Results showed that the modified Gompertz model fitted the results of BMP tests satisfactorily. Furthermore, AT pretreatment promoted BMP (B0) and reduced lag phase (λ) effectively. These were attributed to the solubilization of SMRs. The analyses of the changes in dissolved organic matter indicated that AT pretreatment could facilitate the solubilization of both biodegradable (e.g. protein) and recalcitrant matter (e.g. humic-like, analyzing by EEMs-PARAFAC), which had a significant corresponding positive (Person correlation, p < 0.01) and negative (Partial correlation, p < 0.01) influences on anaerobic biodegradability. However, the positive effects surpassed the negative effects, promoting the overall anaerobic biodegradability of SMRs. In addition, a considerable reduction of ARGs (by 0.62-1.36 log units) was observed at pH ≥ 12, attributed to the hydrolysis of phosphodiester bond of DNA in strong alkaline solution. Considering both anaerobic biodegradability and ARGs, the optimal AT condition was concluded as pH 12, temperature 90 °C and time 120 min.
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Affiliation(s)
- Siqi Song
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Mingye Jiang
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jie Yao
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China; National Engineering Center of Urban Water Resources, 202 Haihe Road, Harbin, 150090, China.
| | - Huiling Liu
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Xiaohu Dai
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Gang Wang
- School of Environment, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin, 150090, China
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10
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Guo Z, Ma L, Dai Q, Ao R, Liu H, Yang J. Combined application of modified corn-core powder and sludge-based biochar for sewage sludge pretreatment: Dewatering performance and dissipative particle dynamics simulation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:115095. [PMID: 32806410 DOI: 10.1016/j.envpol.2020.115095] [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: 04/01/2020] [Revised: 06/22/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Sludge is an inevitable by-product of municipal wastewater treatment processes, and its high moisture content poses a major challenge for its subsequent treatment and disposal. Previous studies have explored the effects of applying modified corn-core powder (MCCP) on dewatering sludge. Here, we characterized the effects of applying both MCCP and sludge-based biochar (SBB) on dewatering sludge. Analysis of the anti-shear ability of SBB revealed that SBB was a skeleton builder with high compressive strength, demonstrating that SBB could maintain the permeability of sludge under high-pressure filtration processes and facilitate the flow of bound water. Dissipative particle dynamics (DPD) was used to simulated the sludge flocculating process and verify the feasibility of the experiment. As the simulation progressed, the reaction in the sludge network reached equilibrium and the simulated structure of the sludge became loose. The dewatering performance and physicochemical properties of the treated sludge were studied to further characterize the effect of this combined technology. Compared with MCCP-sludge, MCCP&SBB-sludge, which was treated by 20% DS (mass of dry solids in sludge) of SBB and 20% DS of MCCP, achieved superior dewaterability. This combined method reduced the specific resistance of filtration by 76% and enlarged the net sludge solids yield by 138%. Further study of the properties of MCCP&SBB-sludge revealed a loose structure that resembled the structure recovered by the simulation, suggesting that the DPD simulation method simulated the sludge flocculating process successfully. Therefore, the combined application of MCCP and SBB was superior for sludge dewatering because of the synergistic effects of MCCP and SBB.
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Affiliation(s)
- Zhiying Guo
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China
| | - Liping Ma
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China.
| | - Quxiu Dai
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China
| | - Ran Ao
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, Yunnan, China
| | - Hongpan Liu
- College of Chemistry and Environmental Engineering, Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, Chongqing University of Arts and Sciences, Chongqing, 402160, China
| | - Jie Yang
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, 610225, Sichuan, China
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11
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Lin F, Zhu X, Li J, Yu P, Luo Y, Liu M. Effect of extracellular polymeric substances (EPS) conditioned by combined lysozyme and cationic polyacrylamide on the dewatering performance of activated sludge. CHEMOSPHERE 2019; 235:679-689. [PMID: 31279118 DOI: 10.1016/j.chemosphere.2019.06.220] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/28/2019] [Accepted: 06/28/2019] [Indexed: 06/09/2023]
Abstract
Extracellular polymeric substance (EPS) and the water within it account for about 80% of the total sludge mass, significantly correlated with sludge charge properties, particle size, and dewaterability, while their relation is still ambiguous. To clarify the effect of EPS characteristics on the activated sludge dewaterability, the sludge conditioned by cationic polyacrylamide (CPAM) and lysozyme alone or in combination was comparatively investigated by the means of the SPSS17 software incorporation with chemical analysis. According to the results, the combined conditioning increased both dewatering extent and dewatering rate with the water content as low as 57.79%. It was mainly attributed to the destruction of microbial cell wall and EPS structure by enzymatic conditioning, beneficial for the release of protein (PN) and polysaccharide (PS), as well as the conversion of intracellular water and some bound water into free water. Additionally, Pearson's correlation and factor analysis confirmed the significant influence of EPS properties on sludge dewaterability and explored their detailed relationship. It was indicated the most crucial factors consisted of PNS (PN in S-EPS), PNL (PN in LB-EPS), PNT (PN in TB-EPS), and PST (PS in TB-EPS) accounted for 72.83% in all of the total variance for the contribution to the dewatered water content. Moreover, the high concentration of PNS and PNL led to the zeta potential rising to -9.74 mV, and the destruction of EPS structure was favorable for sludge to form smaller particle size and compact floc structure. All the results were confirmed by the microstructure changes of the sludge flocs.
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Affiliation(s)
- Feng Lin
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Xiaolin Zhu
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Jigeng Li
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Peiran Yu
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Yong Luo
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Mengru Liu
- State Key Laboratory of Pulp and Paper Engineering, School of Light Industry and Engineering, South China University of Technology, Guangzhou, 510640, China.
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12
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Wei H, Tang Y, Shoeib T, Li A, Yang H. Evaluating the effects of the preoxidation of H 2O 2, NaClO, and KMnO 4 and reflocculation on the dewaterability of sewage sludge. CHEMOSPHERE 2019; 234:942-952. [PMID: 31519103 DOI: 10.1016/j.chemosphere.2019.06.131] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/26/2019] [Accepted: 06/17/2019] [Indexed: 06/10/2023]
Abstract
The preoxidation effects of H2O2, NaClO, and KMnO4 on the dewaterability of sewage sludge were compared by analyzing the changes in specific resistance to filtration (SRF), filter cake moisture content (FCMC), extracellular polymeric substance (EPS) fractions and components, and floc properties. The three oxidants varied in oxidation efficiency and exhibited distinctive mechanisms. NaClO not only destroyed sludge flocs and EPSs but also effectively caused cell lysis, resulting in release of a considerable amount of organic matters and subsequently significant deterioration of dewatering performance. The oxidation of H2O2 and KMnO4 was relatively mild and occurred mainly on the outer layers of the sludge flocs and cell-bound EPSs. By contrast, the SRF and FCMC of the sludge conditioned with a low dose of KMnO4 were slightly improved, and a fraction of soluble EPS was compressed because of the coagulation effect of the oxidation product MnO2. The pH of the sludge conditioned with H2O2 and KMnO4 showed no considerable change. Meanwhile, NaClO evidently increased the alkalinity of the sludge because of the hydrolysis effect. After the pH of the NaClO-treated sludge was readjusted to 7.0, the partial protonation efficiency slightly alleviated the deterioration of sludge dewatering performance. The preoxidized sludge was then subjected to reflocculation treatment using FeCl3, polyacrylamide, and a cationic starch-based flocculant, respectively. The combined treatment of preoxidation and reflocculation showed a high dewatering efficiency owing to their synergistic effect.
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Affiliation(s)
- Hua Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Yunong Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Tamer Shoeib
- Department of Chemistry, The American University in Cairo, New Cairo 11835, Egypt
| | - Aimin Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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13
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Zhang Y, Liu H, Dai X, Cai C, Wang J, Shen Y, Wang P. Variations of physical and chemical properties in relation to erythromycin mycelial dreg dewaterability under heat-activated persulfate oxidation conditioning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:2-9. [PMID: 31202009 DOI: 10.1016/j.scitotenv.2019.05.464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/21/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
Erythromycin mycelial dreg (EMD) resulting from erythromycin (ERY) production process may be used as a nutrient resource. However, it has a high moisture content, which makes handling operations complicated. In this study, the EMD dewaterability under heat-activated persulfate (PS) oxidation conditioning was investigated. The variations of physical and chemical properties of EMD were further investigated to uncover the underlying mechanism of EMD dewaterability. Results indicated that EMD dewaterability was worse under single heat process, but significantly improved under heat-activated PS oxidation process. Heat-activated PS oxidation conditioning was capable to increase zeta potential, reduce median particle size, alter EMD flocs morphology, and disrupt mycelial cells. Concurrently, heat-activated PS oxidation conditioning resulted in the decrease of protein in tightly bound (TB) extracellular polymeric substances (EPS) and total EPS, and the decrease of fluorescing constituents (tryptophan protein, tyrosine protein and tryptophan amino acid) in EPS. Furthermore, a possible mechanism was proposed for heat-activated PS oxidation conditioning.
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Affiliation(s)
- Yanxiang Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Huiling Liu
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Xiaohu Dai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Chen Cai
- School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Jing Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yunpeng Shen
- State Environmental Protection Antibiotic Mycelial Dreg Harmless Treatment And Resource Utilization Engineering Technology Center, Kelun Pharmaceutical Co., Ltd., Yili 835007, China
| | - Peng Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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14
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Bai H, Zhu R, An H, Zhou G, Huang H, Ren H, Zhang Y. Influence of wastewater sludge properties on the performance of electro-osmosis dewatering. ENVIRONMENTAL TECHNOLOGY 2019; 40:2853-2863. [PMID: 29557729 DOI: 10.1080/09593330.2018.1455744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/14/2018] [Indexed: 06/08/2023]
Abstract
Although the properties of municipal wastewater sludge play key roles in the electro-osmosis dewatering process, it is still controversial which properties have the greatest effect on the dewatering performance. In this study, multiple regression models with the Group Lasso method were used to investigate the relationship between the final moisture content and the sludge properties, including pH, electrical conductivity (EC), volatile solids content, zeta potential (ζ), initial moisture content, extracellular polymeric substances (EPS), proteins of EPS (EPSPr), polysaccharides of EPS (EPSPo) and the ratio of EPSPr and EPSPo (EPSR). Under the optimal conditions (pressure = 100 kPa, voltage = 50 V and cake thickness = 15 mm), EPS, EC and ζ were significantly related to sludge dewaterability and EPS was the most important factor. Furthermore, the coefficient estimate of EPSPo was greater than that of EPSPr and the coefficient of EPSR was negative, indicating that EPSPo plays more important roles in electro-osmosis dewatering than EPSPr. Thus, reducing the EPS content of sludge, especially the EPSPo content, is necessary to improve the performance of electro-osmosis dewatering.
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Affiliation(s)
- Hao Bai
- a State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing , People's Republic of China
| | - Rong Zhu
- b Academy of Mathematics and Systems Science, Chinese Academy of Sciences , Beijing , People's Republic of China
| | - Hao An
- a State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing , People's Republic of China
| | - Guoya Zhou
- c Peng Yao Environmental Protection Institute , Yixing , People's Republic of China
| | - Hui Huang
- a State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing , People's Republic of China
| | - Hongqiang Ren
- a State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing , People's Republic of China
| | - Yan Zhang
- a State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing , People's Republic of China
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15
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Xie S, Yu G, Li C, You F, Li J, Tian R, Wang G, Wang Y. Dewaterability enhancement and heavy metals immobilization by pig manure biochar addition during hydrothermal treatment of sewage sludge. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:16537-16547. [PMID: 30980370 DOI: 10.1007/s11356-019-04961-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Hydrothermal treatment (HTT) of sewage sludge (SS) with pig manure biochar (PMB) addition at 160-200 °C was conducted in this study. The effects of PMB addition on the dewaterability of SS and the speciation evolution, leaching toxicity, and potential ecological risk of heavy metals were investigated. The results showed that the solid contents of the filter cakes after adding PMB increased from 20.24%, 24.03%, and 28.69% to 21.57%, 27.69%, and 32.91% at 160, 180, and 200 °C, respectively, compared with traditional HTT of SS. Furthermore, PMB could reduce the bioavailable fractions of Cr, Ni, As, and Cd in the filter cakes obtained at 160 and 180 °C compared with the theoretical value. The leaching toxicity of heavy metals in the filter cakes after adding PMB decreased significantly at 160 and 180 °C and the potential ecological risk index (RI) declined from 62.13 and 44.83 to 55.93 and 42.11, respectively. The obtained filter cake had low potential ecological risk when used in the environment. The mechanisms on the improvement of the dewaterability and heavy metals immobilization were related that PMB acted as the skeleton builder providing the outflow path for free water and implanting heavy metals into SS structure. And the optimal results were obtained at 180 °C during HTT of SS with PMB addition. This work provides a novel and effective method for the treatment of SS.
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Affiliation(s)
- Shengyu Xie
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guangwei Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
| | - Chunxing Li
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Futian You
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Jie Li
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Renqiang Tian
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gang Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yin Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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16
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Wei H, Hu P, Li A, Yang H. Evaluation of acidification and oxidation of sludge to improve the effect of a starch-based flocculant on the dewaterability of sewage sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 231:405-412. [PMID: 30368150 DOI: 10.1016/j.jenvman.2018.10.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 08/27/2018] [Accepted: 10/17/2018] [Indexed: 06/08/2023]
Abstract
Conditioning is essential for achieving effective sludge dewatering and easier disposal. In this study, a combined pretreatment of acidification and oxidation using potassium permanganate (KMnO4) as oxidant was conducted to improve the effect of a cationic starch-based flocculant (St-WH) on the dewaterability of sewage sludge. Synergetic dewatering mechanisms by acidification, oxidation, and flocculation are discussed in detail according to the analysis of the changes in bound water content, extracellular polymeric substances (EPS) fractions and components, zeta potentials, floc size, and surface microstructures of sludge cakes in the dewatering process. Acidification and oxidation could destroy the sludge flocs, thereby causing the degradation of EPS and formation of fine particles. Original loosely and tightly bound EPS partially converted to soluble EPS, resulting in release of trapped water, which can be reflected by the significant correlation between loosely bound EPS and filter cake moisture content (FCMC) (Rs = 0.83, P < 0.05). Those fine particles, simultaneously produced, were adverse to filtration efficiency. In addition to enhancing the oxidation effect of KMnO4, acidification treatment could still compress the protein-like materials in soluble EPS due to protonation effect, which was positively related to specific resistance to filtration (SRF) (Rs = 0.74, P < 0.05). The following flocculation using St-WH efficiently aggregated those fine particles and restrained the released EPS to bind with free water through charge neutralization and bridging effects, thereby resulting in improved filtration performance and enhanced removal of bound water (Rs = 0.88, P < 0.01). Response surface methodology was also applied to achieve an optimal condition and evaluate the effects of various environmental factors.
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Affiliation(s)
- Hua Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Pan Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Aimin Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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17
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Wei H, Gao B, Ren J, Li A, Yang H. Coagulation/flocculation in dewatering of sludge: A review. WATER RESEARCH 2018; 143:608-631. [PMID: 30031298 DOI: 10.1016/j.watres.2018.07.029] [Citation(s) in RCA: 247] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 05/03/2023]
Abstract
Sludge disposal is an integral part of wastewater treatment systems, and its cost usually accounts for more than half of the total operation cost. Sludge disposal technology is facing challenges and opportunities simultaneously and can still be improved. Sludge dewatering is an essential process in sludge disposal, and it is important for the effective reduction of the final processing cost. Coagulation/flocculation is a relatively mature, cost-effective, user-friendly sludge dewatering technology. In this work, coagulation/flocculation and their combinations with other pretreatments, including dewatering mechanisms, are reviewed. Various coagulants/flocculants used in sludge dewatering, including inorganic coagulants, organic synthetic and natural polymeric flocculants, and bioflocculants, are introduced in detail because coagulants/flocculants are the key in coagulation/flocculation. The different factors that influence the dewatering performance of these coagulants/flocculants are also presented briefly. Moreover, aiming at the complicated composition of sludge and its treatment difficulty, the prospects and technical developments of coagulation/flocculation in sludge dewatering are discussed.
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Affiliation(s)
- Hua Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Boqiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Jie Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Aimin Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
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18
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Cai C, Gong P, Wang Y, Wang M, Zhang B, Wang B, Liu H. Investigating the environmental risks from the use of spray-dried cephalosporin mycelial dreg (CMD) as a soil amendment. JOURNAL OF HAZARDOUS MATERIALS 2018; 359:300-306. [PMID: 30045001 DOI: 10.1016/j.jhazmat.2018.07.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/17/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
Cephalosporin mycelial dreg (CMD) is a by-product of the pharmaceutical industry. Spray-drying is widely used for the dewatering process prior to the application of CMD as a soil amendment. However, the potential environmental behaviors and risks of spray-dried CMD amendment remain unclear. Here, a lab-scale incubation experiment was conducted to investigate the salinity, phytotoxicity, introduced antibiotics, heavy metals and the potential impacts of resistance genes in CMD-amended soil. Spray-dried CMD amendment generally increased soil salinity and only high dosed soils showed phytotoxic effects at the end of the incubation period, implying the physiological damage to plant growth. The introduced antibiotics quickly degraded over time, indicating a relatively low environmental persistence. Heavy metal slightly increased in soil receiving spray-dried CMD, and regulations should be developed to avoid metal accumulation. A decreased diversity and distinct patterns of β-lactam resistance genes as well as a dose-effect of their enrichment were observed in CMD-amended soil, which might be partially explained by the specific metals and introduced antibiotics. Antibiotic resistance genes in soil may be a valuable tool for evaluating the environmental risk associated with use of CMD as a soil amendment.
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Affiliation(s)
- Chen Cai
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Picheng Gong
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Yue Wang
- School of Geographical Sciences, Harbin Normal University, Harbin, 150025, China
| | - Mengmeng Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Bo Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Bing Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Huiling Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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