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Kong Z, Wang Z, Lu X, Song Y, Yuan Z, Hu S. Significant in situ sludge yield reduction in an acidic activated sludge system. WATER RESEARCH 2024; 261:122042. [PMID: 38986284 DOI: 10.1016/j.watres.2024.122042] [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: 05/27/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/12/2024]
Abstract
Minimizing sludge generation in activated sludge systems is critical to reducing the operational cost of wastewater treatment plants (WWTPs), particularly for small plants where bioenergy is not recovered. This study introduces a novel acidic activated sludge technology for in situ sludge yield reduction, leveraging acid-tolerant ammonia-oxidizing bacteria (Candidatus Nitrosoglobus). The observed sludge yield (Yobs) was calculated based on the cumulative sludge generation and COD removal during 400 d long-term operation. The acidic process achieved a low Yobs of 0.106 ± 0.004 gMLSS/gCOD at pH 4.6 to 4.8 and in situ free nitrous acid (FNA) of 1 to 3 mg/L, reducing sludge production by 58 % compared to the conventional neutral-pH system (Yobs of 0.250 ± 0.003 gMLSS/gCOD). The acidic system also maintained effective sludge settling and organic matter removal over long-term operation. Mechanism studies revealed that the acidic sludge displayed higher endogenous respiration, sludge hydrolysis rates, and higher soluble microbial products and loosely-bounded extracellular polymer substances, compared to the neutral sludge. It also selectively enriched several hydrolytic genera (e.g., Chryseobacterium, Acidovorax, and Ottowia). Those results indicate that the acidic pH and in situ FNA enhanced sludge disintegration, hydrolysis, and cryptic growth. Besides, a lower intracellular ATP content was observed for acidic sludge than neutral sludge, suggesting potential decoupling of catabolism and anabolism in the acidic sludge. These findings collectively demonstrate that the acidic activated sludge technology could significantly reduce sludge yield, contributing to more cost- and space-effective wastewater management.
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Affiliation(s)
- Zheng Kong
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhiyao Wang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Xi Lu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Yunqian Song
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhiguo Yuan
- School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong 999077, PR China
| | - Shihu Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
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Chi Q, Wang J, Tu Y, Xu J, Pan L, Shen J. Effects of nitrate reduction on the biotransformation of 1H-1,2,4-triazole: Mechanism and community evolution. JOURNAL OF HAZARDOUS MATERIALS 2024; 471:134329. [PMID: 38640679 DOI: 10.1016/j.jhazmat.2024.134329] [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: 07/28/2023] [Revised: 04/09/2024] [Accepted: 04/15/2024] [Indexed: 04/21/2024]
Abstract
Due to the refractory of 1 H-1,2,4-triazole (TZ), conventional anaerobic biological treatment technology is usually restricted by low removal efficiency and poor system stability. In this study, TZ biodegradation and nitrate reduction was coupled to improve the removal efficiency of TZ from polluted wastewater. Batch assay was performed with pure culture strain Raoultella sp. NJUST42, which was reported to have the capability to degrade TZ in our previous study. Based on batch assay result, complete removal of TZ could be achieved in the presence of nitrate, whereas only 50% of TZ could be removed in the control system. Long-term stability experiment indicated that the relative abundance of microorganisms (Bacteroidetes_vadinHA17, Georgenia, Anaerolinea, etc) was obviously enhanced under nitrate reduction condition. During long-term period, major intermediates for TZ biodegradation such as [1,2,4]Triazolidine-3,5-diol, hydrazine dibasic carboxylic acid and carbamic acid were detected. A novel TZ biotransformation approach via hydration, TZ-ring cleavage, deamination and oxidation was speculated. PICRUSt1 and KEGG pathway analyses indicated that hydration (dch), oxidation (adhD, oah, pucG, fdhA) of TZ and nitrate reduction (Nar, napA, nrfA, nirBK, norB, nosZ) were significantly enhanced in the presence of nitrate. Moreover, the significant enrichment of TCA cycle (gab, sdh, fum, etc.) indicated that carbon and energy metabolism were facilitated with the addition of nitrate, thus improved TZ catabolism. The proposed mechanism demonstrated that TZ biodegradation coupled with nitrate reduction would be a promising approach for efficient treatment of wastewater contaminated by TZ.
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Affiliation(s)
- Qiang Chi
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jing Wang
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Yong Tu
- Jiangsu Environmental Engineering Technology Co., Ltd., Nanjing 210094, China
| | - Jing Xu
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Ling Pan
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jinyou Shen
- Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
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Fu Y, Wu J, Wu Y, Yang B, Wang X, Xu R, Meng F. Development of a novel membrane-based quorum-quenching microbial isolator for biofouling control: Process performance and microbial mechanism. BIORESOURCE TECHNOLOGY 2024; 402:130817. [PMID: 38723725 DOI: 10.1016/j.biortech.2024.130817] [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: 03/19/2024] [Revised: 05/03/2024] [Accepted: 05/06/2024] [Indexed: 05/14/2024]
Abstract
Quorum quenching (QQ) can mitigate biofouling in membrane bioreactors (MBRs) by inhibiting cell-to-cell communication. However, it is difficult to maintain long-term QQ activity. Here, a novel microbial isolator composed of tubular microfiltration membranes was developed to separate QQ bacteria (Rhodococcus sp. BH4) from sludge. The time to reach a transmembrane pressure of 50 kPa was delayed by 69.55 % (p = 0.002, Student's t test) in MBR with QQ microbial isolator (MBR-Q), compared to that in the control MBR (MBR-C) during stable operation. The concentration of proteins in the extracellular polymeric substances of sludge was reduced by 20.61 % in MBR-Q relative to MBR-C. The results of the bacterial community analyses indicated less enrichment of fouling-associated bacteria (e.g., Acinetobacter) but a higher abundance of QQ enzymes in MBR-Q than in MBR-C. This environmentally friendly technique can decrease the cleaning frequency and increase the membrane lifespan, thus improving the sustainability of MBR technology.
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Affiliation(s)
- Yue Fu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Jiajie Wu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Yingxin Wu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Boyi Yang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Xiaolong Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
| | - Ronghua Xu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China.
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (Sun Yat-sen University), Guangzhou 510275, PR China
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Ren W, Zhang S, Liu Y, Ju W, Liu G, Xie K. Study on efficiency and mechanism of ultrasonic controlling membrane fouling in ceramic membrane bioreactors. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e11032. [PMID: 38698675 DOI: 10.1002/wer.11032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 05/05/2024]
Abstract
In recent years, ceramic membranes have been increasingly used in membrane bioreactors (MBRs). However, membrane fouling was still the core issue restricting the large-scale engineering application of ceramic MBRs. As a novel and alternative technology, ultrasonic could be used to control membrane fouling. This research focused on the efficiency and mechanism of ultrasonic controlling membrane fouling in ceramic MBRs. The results showed that ultrasonic reduced the sludge concentration in MBR, and the average particle size of sludge was always in a high range. The sludge activity of the system was stable at 6-9 (mg O2·(g MLSS·h)-1), indicating that ultrasonic did not destroy the activity of microorganisms in the system. The extracellular polymer substance (EPS) of the ultrasonic group was slightly higher than that of the control group, while the soluble microbial product (SMP) content was relatively stable. The ceramic membrane of the ultrasonic group has a partial retention effect on the organic components. The application of ultrasonic slowed down the decrease of the hydrophilicity of the ceramic membrane. The main pollutants on the membrane surface exist in the form of aromatic and heteroaromatic rings, alkynes, and so forth. Ultrasonic removes the amide substances from the membrane surface. Membrane fouling resistance is mainly due to membrane pore blockage, accounting for 75.53%. PRACTITIONER POINTS: Enrich the research on the mechanism of ultrasonic technology in membrane fouling control. The MBR can still operate normally with ultrasonic applied. The time for the ceramic membrane to reach the fouling end point is 2.4 times that without ultrasonic. The main cause of membrane fouling was pore blocking, accounting for 75.53%.
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Affiliation(s)
- Wenyi Ren
- School of Civil Engineering and Architecture, University of Jinan, Jinan, China
| | - Shoubin Zhang
- School of Civil Engineering and Architecture, University of Jinan, Jinan, China
| | - Yutian Liu
- Jinan Municipal Engineering Design &Research Institute (Group) CO., LTD., Jinan, China
| | - Weipeng Ju
- Jinan Municipal Engineering Design &Research Institute (Group) CO., LTD., Jinan, China
| | - Guicai Liu
- School of Civil Engineering and Architecture, University of Jinan, Jinan, China
| | - Kang Xie
- School of Civil Engineering and Architecture, University of Jinan, Jinan, China
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Kim J, Bae E, Park H, Park HJ, Shah SSA, Lee K, Lee J, Oh HS, Park PK, Shin YC, Moon H, Naddeo V, Choo KH. Membrane reciprocation and quorum quenching: An innovative combination for fouling control and energy saving in membrane bioreactors. WATER RESEARCH 2024; 250:121035. [PMID: 38154339 DOI: 10.1016/j.watres.2023.121035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/27/2023] [Accepted: 12/18/2023] [Indexed: 12/30/2023]
Abstract
Membrane bioreactors (MBRs) play a crucial role in wastewater treatment, but they face considerable challenges due to fouling. To tackle this issue, innovative strategies are needed. This study investigated the effectiveness of membrane reciprocation and quorum quenching (QQ) to control fouling in MBRs. The study compared MBRs using membrane reciprocation (30 rpm) and QQ (injecting media containing 100 or 200 mg/L BH4) with conventional MBRs employing different air-scouring intensities. The results demonstrated that combining membrane reciprocation (30 rpm) with QQ (200 mg/L BH4) significantly extended the service time of MBRs, making it approximately six times longer than conventional methods. Moreover, this approach reduced physically reversible resistance. The reduction in signal molecules related to biofouling due to QQ showcased its critical role in controlling biofouling, even under high shear caused by membrane reciprocation. However, the impact of QQ on microbial community structure appeared relatively insignificant when compared to factors such as operation time, aeration intensity, and membrane reciprocation. By combining membrane reciprocation and QQ, the study achieved a remarkable 81 % energy saving compared to extensive aeration (103 s-1 in velocity gradient), in addition to the extended service time. Importantly, this combined antifouling approach did not negatively affect microbial characteristics and wastewater treatment, emphasizing its effectiveness in MBRs. Overall, the findings of this study offer valuable insights for developing synergistic fouling control strategies in MBRs, significantly improving the energy efficiency of the wastewater treatment process.
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Affiliation(s)
- Jinwoo Kim
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Eunjin Bae
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; Daegu Metropolitan City Waterworks Headquarters (Water Quality Research Institute), 176 Dangsan-ro, Dalseo-gu, Daegu 42650, Republic of Korea
| | - Hyeona Park
- Advanced Institute of Water Industry, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Hyung-June Park
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea
| | - Syed Salman Ali Shah
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Guangdong 519087, China
| | - Kibaek Lee
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jaewoo Lee
- Department of Polymer-Nano Science and Technology, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 54896, Republic of Korea
| | - Hyun-Suk Oh
- Department of Environmental Engineering, Seoul National University of Science & Technology, Seoul 01811, Republic of Korea
| | - Pyung-Kyu Park
- Department of Environmental and Energy Engineering, Yonsei University, Wonju, Gangwon-do 26439, Republic of Korea
| | - Yong Cheol Shin
- HifilM, 24 Deokseongsandan 2-ro, Idong-eup, Cheoin-gu, Yongin, Gyeonggi-do 17130, Republic of Korea
| | - HeeWan Moon
- HifilM, 24 Deokseongsandan 2-ro, Idong-eup, Cheoin-gu, Yongin, Gyeonggi-do 17130, Republic of Korea
| | - Vincenzo Naddeo
- Sanitary Environmental Engineering Division, Department of Civil Engineering, University of Salerno, via Giovanni Paolo II, Fisciano, SA 84084, Italy
| | - Kwang-Ho Choo
- School of Architectural, Civil, Environmental, and Energy Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; Advanced Institute of Water Industry, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea; Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Republic of Korea.
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Zhou Z, Sun Y, Fu L, Zuo Y, Shao Y, Wang L, Zhou C, An Y. Unravelling roles of the intermediate settler in a microaerobic hydrolysis sludge in situ reduction process. BIORESOURCE TECHNOLOGY 2023:129228. [PMID: 37244312 DOI: 10.1016/j.biortech.2023.129228] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/13/2023] [Accepted: 05/21/2023] [Indexed: 05/29/2023]
Abstract
The roles of the intermediate settler in the sludge process reduction activated sludge process (SPRAS), and the influences of its hydraulic retention time (HRTST) on pollutant removal and sludge reduction were investigated. Prolonging HRTST from 3.0 to 4.5 and 6.0 h resulted in sludge reduction efficiencies increased from 46.8% to 61.5% and 62.7%. The sludge accumulation in the intermediate settler formed an anaerobic zone but inhibited methane production, and the alternating microaerobic and anaerobic environment in the sludge process reduction (SPR) module increased the microbial diversity and enriched the hydrolytic and fermentative bacteria. Prolonging HRTST accelerated dissolved organic matter release and elevated the degradation of refractory fraction, and improved the sludge properties of the SPRAS. Metagenomic analysis showed that the SPR module enhanced the glycolysis pathway and decoupling metabolism for sludge reduction. The results revealed that the intermediate settler plays dual roles in solid-liquid separation and sludge reduction metabolism.
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Affiliation(s)
- Zhen Zhou
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Yiyue Sun
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Li Fu
- Powerchina Zhongnan Engineering Corporation Limited, Changsha 410014, China
| | - Yi Zuo
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Yanjun Shao
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Lihua Wang
- Shanghai Chengtou Wastewater Treatment Co., Ltd, Shanghai 201203, China
| | - Chuanting Zhou
- Shanghai Urban Construction Design and Research Institute, Shanghai 200125, China
| | - Ying An
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China.
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Jiang LM, Zhang Z, Li Y, Xu J, Wang K, Ding X, He J, Qiu Z, Zhou H, Zhou Z. Under-loaded operation of an anaerobic-anoxic-aerobic system in dry and wet weather dynamics to prevent overflow pollution: Impacts on process performance and microbial community. BIORESOURCE TECHNOLOGY 2023; 376:128837. [PMID: 36898557 DOI: 10.1016/j.biortech.2023.128837] [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: 01/29/2023] [Revised: 02/28/2023] [Accepted: 03/04/2023] [Indexed: 06/18/2023]
Abstract
Effects of low hydraulic loading rate (HLR) in dry weather and high HLR in wet weather on pollutant removal, microbial community, and sludge properties of a full-scale wastewater treatment plant (WWTP) were extensively studied to explore the risk of under-loaded operation for overflow pollution control. Long-term low HLR operation had an insignificant effect on the pollutant removal performance of the full-scale WWTP, and the system could withstand high-load shocks in wet weather. Low HLR resulted in higher oxygen and nitrate uptake rate due to the storage mechanism under the alternating feast/famine condition, and lower nitrifying rate. Low HLR operation enlarged particle size, deteriorated floc aggregation and sludge settleability, and reduced sludge viscosity due to the overgrowth of filamentous bacteria and inhibition of floc-forming bacteria. The remarkable increase in Thuricola and the contract morphology of Vorticella in microfauna observation confirmed the risk of flocs disintegration in low HLR operation.
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Affiliation(s)
- Lu-Man Jiang
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Zhenjian Zhang
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Yunhui Li
- Shanghai Chengtou Water (Group) Co., Ltd, Shanghai 200002, China
| | - Jialei Xu
- Shanghai Chengtou Water (Group) Co., Ltd, Shanghai 200002, China
| | - Kun Wang
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Xinya Ding
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Junli He
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China
| | - Zhan Qiu
- Shanghai Chengtou Water (Group) Co., Ltd, Shanghai 200002, China
| | - Hua Zhou
- Shanghai Chengtou Water (Group) Co., Ltd, Shanghai 200002, China
| | - Zhen Zhou
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, China.
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