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Xu Y, Li Q, Tang Y, Huang H, Ren H. Electrocatalytic denitrification biofilter for advanced purification of chlorophenols via ceramsite-based Ti/SnO 2-Sb particle electrode: Performance, microbial community structure and mechanism. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 346:123594. [PMID: 38378077 DOI: 10.1016/j.envpol.2024.123594] [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: 12/15/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/22/2024]
Abstract
In response to the demand for advanced purification of industrial secondary effluent, a new method has been developed for treating chlorophenol wastewater using the novel ceramsite-based Ti/SnO2-Sb particle electrodes (Ti/SnO2-Sb/CB) enhanced electrocatalytic denitrification biofilter (EDNBF-P) to achieve removal of chlorophenols (CPs), denitrification, and reduction of effluent toxicity. The results showed that significantly improved CPs and TN removal efficiency at low COD/N compared to conventional denitrification biofilter, with CPs removal rates increasing by 0.33%-59.27% and TN removal rates increasing by 12.53%-38.92%. Under the conditions of HRT = 2h, 3V voltage, charging times = 12h, and 25 °C, the concentrations of the CPs in the effluent of EDNBF-P were all below 1 mg/L, the TN concentration was below 15 mg/L, while the effluent toxicity reached the low toxicity level. Additionally, the Ti/SnO2-Sb/CB particle electrodes effectively alleviated the accumulation of NO2--N caused by applied voltage. The Silanimonas, Pseudomonas and Rhodobacter was identified as the core microorganism for denitrification and toxicity reduction. This study validated that EDNBF-P could achieve synergistic treatment of CPs and TN through electrocatalysis and microbial degradation, providing a methodological support for achieving advanced purification of chlorophenol wastewater with low COD/N in industrial applications.
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Affiliation(s)
- Yujin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Qianqian Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Yingying Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
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Fang X, Yan Y, Xu Y, Huang H, Ren H. Advanced electrolysis sulfur-based biofiltration for simultaneous total nitrogen removal and estrogen toxicity reduction from low carbon-to-nitrogen ratio wastewater. BIORESOURCE TECHNOLOGY 2024; 396:130418. [PMID: 38325611 DOI: 10.1016/j.biortech.2024.130418] [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: 12/13/2023] [Revised: 01/24/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
A sulfur-based biofilter enhanced by phosphate modified activated carbon as particle electrodes was constructed to simultaneously remove total nitrogen (TN) and estrogen from low carbon-to-nitrogen ratio (C/N) wastewater containing 1 mg/L 17-alpha-ethinylestradiol (EE2). Results showed that the enhanced biofilter achieved outstanding performance in EE2 removal (93.2 %) and TN reduction (effluent < 5 mg/L), demonstrating robustness against C/N fluctuations. It was noteworthy that it successfully reduced both acute toxicity (59.5 %) and estrogenic activity (88.6 %). Comprehensive characterization investigations and microbial community structure analysis revealed that enhanced electron transfer and increased microbial abundance likely contributed to improved biofilter performance. Core microorganisms, such as Pseudomonas and Chryseobacterium were identified as key contributors to synergistic estrogen degradation and denitrification. This study presented a feasible and promising strategy of combined process with three-dimensional electrodes and sulfur-based biofilter, highlighting substantial potential for advanced purification and safe reuse of wastewater.
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Affiliation(s)
- Xiaoya Fang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yujie Yan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yujin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
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Yan Y, Jin K, Huang H, Wang Y, Li T, Wang L, Wang Q, Ren H. Estrogen toxicity reduction of industrial biochemical tailwater by electrolysis biofilters with ceramsite‑sulfur-siderite fillers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 864:161103. [PMID: 36581296 DOI: 10.1016/j.scitotenv.2022.161103] [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: 10/02/2022] [Revised: 12/17/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Biochemical tailwater of the industrial park wastewater treatment plant is facing the growing demand of advanced treatment and toxicity reduction. However, existing information on toxicity reduction of real industrial biochemical tailwater is still limited so far. Herein, the water quality of biochemical tailwater from an integrated industrial park in Taihu Lake Basin, China, was systematically investigated, and typical endocrine disrupting chemicals (EDCs) and estrogen toxicity were detected. Estrogen toxicity reduction by previously proposed electrolysis biofilters with ceramsite‑sulfur-siderite fillers was further verified. Results showed that total nitrogen (TN) and estrogen toxicity removal increased by 41.0 % and 30.3 % respectively under the optimal voltage of 4 V and electric loading of 24 h/d, and significantly positive correlation between estrogen toxicity reduction and TN removal (p < 0.05) was observed. The lowest effluent estrogen toxicity was 0.79-0.95 ngE2/L (in estradiol equivalent concentration) by the biofilter with ceramsite‑sulfur-siderite fillers, which was lower than the estrogen disruption effects mass concentration threshold of 1 ng/L. Electrical stimulation promoted the increase of the abundance of denitrifying bacteria Thauera and electroactive bacteria Hydrogenophaga, thus enhancing the removal of TN, furthermore, the abundance of Thiobacillus and Sulfuritalea were significantly correlated with the reduction of estrogen toxicity. The study highlights the potential of electrolysis biofilter in realizing the synergy of estrogen toxicity reduction and autotrophic denitrification of industrial biochemical tailwater, and paves the way for the application of electrolysis biofilter in the advanced purification of industrial biochemical tailwater.
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Affiliation(s)
- Yujie Yan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Kai Jin
- Yixing Environmental Research Institute of Nanjing University, Yixing 214200, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China; Yixing Environmental Research Institute of Nanjing University, Yixing 214200, Jiangsu, PR China.
| | - Yanru Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China; Yixing Environmental Research Institute of Nanjing University, Yixing 214200, Jiangsu, PR China
| | - Tong Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Laichun Wang
- Yixing Environmental Research Institute of Nanjing University, Yixing 214200, Jiangsu, PR China
| | - Qing Wang
- Yixing Environmental Research Institute of Nanjing University, Yixing 214200, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China; Yixing Environmental Research Institute of Nanjing University, Yixing 214200, Jiangsu, PR China
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Tang Y, Li T, Xu Y, Ren H, Huang H. Effects of electrical stimulation on purification of secondary effluent containing chlorophenols by denitrification biofilter. ENVIRONMENTAL RESEARCH 2023; 216:114535. [PMID: 36223835 DOI: 10.1016/j.envres.2022.114535] [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: 08/24/2022] [Revised: 09/30/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
The coexistence of chlorophenols (CPs) and total nitrogen (TN) is common in advanced purification of industrial secondary effluent, which brings challenges to conventional denitrification biofilters (DNBFs). Electrical stimulation is an effective method for the degradation of CPs, However, the application of electrical stimulation in DNBFs to enhance the treatment of secondary effluent containing CPs remains largely unknown. Herein, this study conducted a systematic investigation towards the effects of electrical stimulation on DNBF through eight lab-scale reactors at room and low temperatures and different hydraulic retention times (HRTs). Results showed that the electrical stimulation effect was not greatly affected by temperature and the optimal applied voltage was 3 V. Overall, the removal rates of TN and CPs were increased by 114%-334% and 2.68%-34.79% respectively after electrical stimulation. When the influent concentration of NO3--N, COD and each CP of 25 mg/L, 50 mg/L and 5 mg/L, about 15 mg/L of effluent TN could be achieved and the removals of p-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol were increased by 10.58%, 5.78% and 34.79% respectively, under the voltage of 3 V and HRT of 4 h. However, the reduction rate of biotoxicity was decreased and could not achieve low toxicity grade in general. Electrical stimulation promoted the elevation of Hydrogenophaga and thus enhanced the removal of TN, and the increase of Microbacterium and Ahniella was significantly associated with the improvement of CPs removal rate. In addition, the obvious accumulation of nitrite was found to be significantly negatively correlated with the abundance of Nitrospira. This study highlighted a further need for the optimization of electrical stimulation in DNBFs treating industrial secondary effluent containing CPs to achieve the goal of pollutant removal and toxicity reduction simultaneously.
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Affiliation(s)
- Yingying Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Tong Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Yujin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
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Li T, Gao Y, Tang Y, Xu Y, Ren H, Huang H. A new LDH based sustained-release carbon source filter media to achieve advanced denitrogenation of low C/N wastewater at low temperature. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156488. [PMID: 35671857 DOI: 10.1016/j.scitotenv.2022.156488] [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: 02/13/2022] [Revised: 05/23/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Advanced denitrogenation of wastewater is now facing major challenges brought by low C/N ratio and low temperature. The development of sustained-release materials with good and stable carbon release properties was an effective countermeasure. FeNi-Layered double-metal hydroxides (LDH)- sodium carboxymethyl cellulose (CMC) filter media and its potential use in heterotrophic and sulfur-based mixotrophic denitrification biological filter (DNBF), was firstly reported. It demonstrated stable structure and good carbon release performance with a mass transfer coefficient (K) of 4.40 mg·L-1·s-1. When the influent NO3--N of 50 mg/L with the C/N ratio of 3 at 10 °C, the maximum nitrogen loading rate of 0.22 kg·N/(m3·d) and effluent TN close to 5 mg/L (nitrogen removal of almost 90 %) could be achieved. The slowly released carbon source and the leached iron increased the abundance of denitrifying bacteria and functional genes, and the augmentation of Sulfuritalea and the secretion of biofilm protein stimulated by sulfur also played a synergistic role. This study provided a new potentially effective strategy to enhance advanced denitrification of wastewater of low C/N wastewater at low temperature.
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Affiliation(s)
- Tong Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yilin Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yingying Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Yujin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
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Xu F, Sun R, Wang H, Wang Y, Liu Y, Jin X, Zhao Z, Zhang Y, Cai W, Wang C, Kong Q. Improving the outcomes from electroactive constructed wetlands by mixing wastewaters from different beverage-processing industries. CHEMOSPHERE 2021; 283:131203. [PMID: 34147984 DOI: 10.1016/j.chemosphere.2021.131203] [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: 04/28/2021] [Revised: 06/05/2021] [Accepted: 06/09/2021] [Indexed: 06/12/2023]
Abstract
Denitrification in electroactive constructed wetland (EW) systems is constrained by the carbon source and the carbon/nitrogen (C/N) ratio (the COD/TN ratio). In this study, wastewater with a high C/N from a brewery was added to wastewater with a low C/N (dairy wastewater) in an EW system, and the pollutant removal, bioelectricity generation, transformations of dissolved organic matter, and microbial community structures were evaluated. The results showed that the average removal rates of ammonium nitrogen, total nitrogen, and chemical oxygen demand from the wastewater mixture were 6.40%, 46.44%, and 23.85% higher than those from the wastewater with a low C/N, respectively. Dissimilatory nitrate reduction to ammonium was effectively inhibited, and the NH4+-N removal was 25.52% higher, when the wastewater mixture was used instead of the high C/N wastewater. Similarly, the output voltage was significantly increased, and the internal resistance of the device was reduced, for the wastewater mixture. The structure of the microbial community improved, the relative abundance of electrochemically active bacteria was higher, and the protein-like and humic-like components were lower, in the mixture treatment than in the individual treatment. The results show that the nitrogen removal and biopower generation improved in an EW system when high C/N wastewater was used as the carbon source.
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Affiliation(s)
- Fei Xu
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China
| | - Ruipeng Sun
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China
| | - Hao Wang
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China
| | - Yuting Wang
- College of Arts, Shandong Management University, Jinan, 250357, PR China
| | - Yongming Liu
- Shandong Provincial Geo-Mineral Engineering Co., Ltd., Jinan, 250013, PR China
| | - Xing Jin
- Shandong Provincial Geo-Mineral Engineering Co., Ltd., Jinan, 250013, PR China
| | - Zheng Zhao
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China
| | - Yujia Zhang
- College of Life Science, Shandong Normal University, Jinan, 250014, PR China
| | - Wenjun Cai
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China
| | - Chunxiao Wang
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China
| | - Qiang Kong
- College of Geography and Environment, Shandong Normal University, Jinan, 250014, PR China.
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Liu H, Kong T, Qiu L, Xu R, Li F, Kolton M, Lin H, Zhang L, Lin L, Chen J, Sun X, Gao P, Sun W. Solar-driven, self-sustainable electrolysis for treating eutrophic river water: Intensified nutrient removal and reshaped microbial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:144293. [PMID: 33385655 DOI: 10.1016/j.scitotenv.2020.144293] [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: 09/13/2020] [Revised: 11/15/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
River ecosystems are the most important resource of surface freshwater, but they have frequently been contaminated by excessive nutrient input of nitrogen (N) and phosphorus (P) in particular. An efficient and economic river water treatment technology that possesses the capacity of simultaneous N and P removal is urgently required. In this study, a solar-driven, self-sustainable electrolytic treatment was conducted in situ to intensify N and P removal from eutrophic river water. Solar panel was applied to provide the electrolysis setups with energy (voltage 10 ± 0.5 V), and the current density was controlled to be 0.06 ± 0.02 mA cm-2. Results indicated that the average removal efficiencies of total N (TN) and total P (TP) under electrolysis conditions reached 72.4 ± 11.7 and 13.8 ± 5.3 mg m-2 d-1, which were 3.7- and 4.7-fold higher compared to untreated conditions. Enhanced TN removal mainly reflected the abatement of nitrate N (NO3--N) (80.6 ± 4.1%). The formation of ferric ions through the electro-dissolution of the sacrificial iron anode improved TP removal by coprecipitation with SPS. Combined high-throughput sequencing and statistical analyses revealed that electrolysis significantly reshaped the microbial communities in both the sediment-water interface and suspended sediment (SPS), and hydrogenotrophic denitrifiers (e.g., Hydrogenophaga) were highly enriched under electrolysis conditions. These findings indicated that in situ electrolysis is a feasible and effective technology for intensified nutrient removal from river water.
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Affiliation(s)
- Huaqing Liu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Tianle Kong
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Lang Qiu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Rui Xu
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Fangbai Li
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Max Kolton
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Hanzhi Lin
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Lei Zhang
- Research Institute of Petrochemical and Fine Chemical Engineering, Guangzhou 510665, PR China
| | - Lan Lin
- Research Institute of Petrochemical and Fine Chemical Engineering, Guangzhou 510665, PR China
| | - Jiazhi Chen
- Research Institute of Petrochemical and Fine Chemical Engineering, Guangzhou 510665, PR China
| | - Xiaoxu Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Pin Gao
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Weimin Sun
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-environmental Science & Technology, Guangdong Academy of Sciences, Guangzhou 510650, China.
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Gao Y, Huang H, Peng C, Fan X, Hu J, Ren H. Simultaneous nitrogen removal and toxicity reduction of synthetic municipal wastewater by micro-electrolysis and sulfur-based denitrification biofilter. BIORESOURCE TECHNOLOGY 2020; 316:123924. [PMID: 32745998 DOI: 10.1016/j.biortech.2020.123924] [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: 06/14/2020] [Revised: 07/21/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Simultaneous nitrogen removal and toxicity reduction are critical for safe reuse of wastewater, but research in this area is limited. In this study, micro-electrolysis and sulfur-based denitrification biofilters (DNBFs) were applied for simultaneous nitrogen removal and toxicity reduction for municipal wastewater. When COD was 250 ± 1 mg/L, NO3--N was 50 ± 1 mg/L, total nitrogen (TN) of effluent was below 5 mg/L with the nitrogen load of 0.149 kg N/(m3·d) in all the reactors, while the effect of electrolysis on TN removal was not obvious. Micro-electrolysis promoted toxicity reduction by 8.7-17.4% only in sulfur-based DNBFs, and it also increased biofilm PN/PS by 7.56-43.46% and enhanced Cloacibacterium's abundance responsible for toxicity reduction (p < 0.05). Introduction of sulfur resulted in the contribution of sulfur-based autotrophic denitrification up to 21.48% and Sulfurimonas mainly contributed to toxicity reduction (p < 0.05).
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Affiliation(s)
- Yilin Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China.
| | - Chong Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Xuan Fan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jun Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
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