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Lv S, Zhang S, Zhang M, Liu F, Cheng L. Effects of multi-plant harvesting on nitrogen removal and recovery in constructed wetlands. CHEMOSPHERE 2024; 353:141550. [PMID: 38408572 DOI: 10.1016/j.chemosphere.2024.141550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/08/2024] [Accepted: 02/23/2024] [Indexed: 02/28/2024]
Abstract
The harvesting of plants is considered an effective method for nutrient recovery in constructed wetlands (CWs). However, excessive plant harvesting can lead to a decrease in plant biomass. It remains unclear what harvesting frequency can optimize plant nutrient uptake and pollutant removal. In this study, CWs planted with Myriophyllum aquaticum were constructed, and three different frequencies of plant harvesting (high: 45 days/time; low: 90 days/time; none: CK) were set to investigate nitrogen removal and its influencing mechanism, as well as the capacity for plant nutrient recovery. The results showed that the average removal efficiencies of ammonia nitrogen (NH4+-N) at 45 days/time, 90 days/time, and CK were 90.3%, 90.8%, and 88.3% respectively, while the corresponding total nitrogen (TN) were 61.2%, 67.4%, and 67.4%. Dissolved oxygen (DO) concentration and water temperature were identified as the main environmental factors affecting nitrogen removal efficiency. Low harvest frequency (90 days/time) increased DO concentration and NH4+-N removal efficiency without impacting TN removal. Additionally, TN recovery from plants under high and low harvest was found to be approximately 9.21-9.32 times higher than that from no harvest conditions. The above studies indicated that a harvest frequency of every 90 days was one appropriate option for M. aquaticum, which not only increased NH4+-N removal efficiencies but also facilitated more efficient nitrogen recovery from the wetland system.
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Affiliation(s)
- Shuangtong Lv
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Shunan Zhang
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China.
| | - Miaomiao Zhang
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China
| | - Feng Liu
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Lihua Cheng
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China; College of Resources, Hunan Agricultural University, Hunan 410128, China
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2
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Li L, Zhang J, Shi Q, Lu S. Comparison of nitrogen removal performance and mechanism from low-polluted wastewater by constructed wetlands with two oxygen supply strategies: Tidal flow and intermittent aeration. CHEMOSPHERE 2023; 313:137364. [PMID: 36427582 DOI: 10.1016/j.chemosphere.2022.137364] [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: 08/03/2022] [Revised: 11/01/2022] [Accepted: 11/21/2022] [Indexed: 06/16/2023]
Abstract
Due to dissolved oxygen (DO) limited nitrogen removal efficiency in constructed wetlands (CWs), two representative oxygen-suppling CWs, i.e., tidal flow constructed wetlands (TFCWs) and intermittently aerated constructed wetlands (IACWs) were proposed to compare the effect of oxygen supply strategies on the nitrogen removal performance and mechanism. Results showed that the removal efficiencies of NH4+-N and COD in IACWs were as high as 90.35-97.14% and 91.14-92.44%, respectively. In terms of TN, TFCWs (83.82%) showed a significantly higher removal efficiency than IACWs, and this result was derived with the flooded/drained phase (FP/DP) ratio of 21 h:3 h in TFCWs, because rhythmic FP and DP formed a high oxygen gradient at different depths of the system, which intensified the nitrification and denitrification simultaneously. The potential nitrifying and denitrifying bacteria (e.g., Nitrospira, Azospira, Haliangium, Bradyrhizobium and Arenimonas) were enriched more significantly in TFCWs compared with IACWs, as well as Bacillus for simultaneous nitrification and denitrification, which promoted nitrogen transformation together. Also, the results of molecular ecological network analysis showed that bacterial community structure in IACWs was more complex and robust than in TFCWs, because there were obviously more nodes and links as well as a higher proportion of negative interference. However, the relationship between genera in TFCWs was closer depending on shorter path distances, and the keystone genus (Nitrosomonas) in related to nitrification was considered to play an important role in nitrogen transformation performance.
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Affiliation(s)
- Linlin Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, State Environmental Protection Key Laboratory for Lake Pollution Control, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; College of Water Science, Beijing Normal University, Beijing, 100875, PR China
| | - Jing Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, State Environmental Protection Key Laboratory for Lake Pollution Control, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China
| | - Qiuyue Shi
- State Key Laboratory of Environmental Criteria and Risk Assessment, State Environmental Protection Key Laboratory for Lake Pollution Control, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China
| | - Shaoyong Lu
- State Key Laboratory of Environmental Criteria and Risk Assessment, State Environmental Protection Key Laboratory for Lake Pollution Control, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China; College of Water Science, Beijing Normal University, Beijing, 100875, PR China.
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3
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Zou Y, Yang Y, Wu S, Chen F, Zhu R. Effect of steel slag on ammonia removal and ammonia-oxidizing microorganisms in zeolite-based tidal flow constructed wetlands. CHEMOSPHERE 2022; 309:136727. [PMID: 36209854 DOI: 10.1016/j.chemosphere.2022.136727] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 09/07/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
The ammonia removal performance of tidal flow constructed wetlands (TFCWs) requires to be improved under high hydraulic loading rates (HLRs). The pH decrease caused by nitrification may adversely affect the NH4+-N removal and ammonia-oxidizing microorganisms (AOMs) of TFCWs. Herein, TFCWs with zeolite (TFCW_Z) and a mixture of zeolite and steel slag (TFCW_S) were built to investigate the influence of steel slag on NH4+-N removal and AOMs. Both TFCWs were operated under short flooding/drying (F/D) cycles and high HLRs (3.13 and 4.69 m3/(m2 d)). The results revealed that a neutral effluent pH (6.98-7.82) was achieved in TFCW_S owing to the CaO dissolution of steel slag. The NH4+-N removal efficiencies in TFCW_S (91.2 ± 5.1%) were much higher than those in TFCW_Z (73.2 ± 7.1%). Total nitrogen (TN) removal was poor in both TFCWs mainly due to the low influent COD/TN. Phosphorus removal in TFCW_S was unsatisfactory because of the short hydraulic retention time. The addition of steel slag stimulated the flourishing AOMs, including Nitrosomonas (ammonia-oxidizing bacteria, AOB), Candidatus_Nitrocosmicus (ammonia-oxidizing archaea, AOA), and comammox Nitrospira, which may be responsible for the better ammonia removal performance in TFCW_S. PICRUSt2 showed that steel slag also enriched the relative abundance of functional genes involved in nitrification (amoCAB, hao, and nxrAB) but inhibited genes related to denitrification (nirK, norB, and nosZ). Quantitative polymerase chain reaction (qPCR) revealed that complete AOB (CAOB) and AOB contributed more to the amoA genes in TFCW_S and TFCW_Z, respectively. Therefore, this study revealed that the dominant AOMs could be significantly changed in zeolite-based TFCW by adding steel slag to regulate the pH in situ, resulting in a more efficient NH4+-N removal performance.
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Affiliation(s)
- Yuhuan Zou
- CAS Key Laboratory of Mineralogy and Metallogeny & Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, 511 Kehua Street, Guangzhou, 510640, China; University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China
| | - Yongqiang Yang
- CAS Key Laboratory of Mineralogy and Metallogeny & Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, 511 Kehua Street, Guangzhou, 510640, China.
| | - Shijun Wu
- CAS Key Laboratory of Mineralogy and Metallogeny & Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, 511 Kehua Street, Guangzhou, 510640, China
| | - Fanrong Chen
- CAS Key Laboratory of Mineralogy and Metallogeny & Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, 511 Kehua Street, Guangzhou, 510640, China
| | - Runliang Zhu
- CAS Key Laboratory of Mineralogy and Metallogeny & Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, 511 Kehua Street, Guangzhou, 510640, China
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4
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Zhou M, Cao J, Lu Y, Zhu L, Li C, Wang Y, Hao L, Luo J, Ren H. The performance and mechanism of iron-modified aluminum sludge substrate tidal flow constructed wetlands for simultaneous nitrogen and phosphorus removal in the effluent of wastewater treatment plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157569. [PMID: 35882329 DOI: 10.1016/j.scitotenv.2022.157569] [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: 05/17/2022] [Revised: 07/17/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Aiming at the poor N and P removal performance in the effluent of wastewater treatment plants by constructed wetlands (CWs), aluminum sludge (AS) from water supply plants was used to prepare iron-modified aluminum sludge (IAS), and tidal flow constructed wetlands (TFCWs) using IAS as substrates were constructed. By means of high-throughput sequencing, X-ray diffractometer (XRD), etc., the removal mechanism of N and P in the system and fate analysis of key elements were also interpreted. Results showed that an interlayer structure beneficial to adsorbing pollutants was formed in the IAS, due to the iron scraps entering into the molecular layers of AS. The removal rates of TP and TN by IAS-TFCWs reached 95 % and 47 %, respectively, when the flooding/resting time (F/R) and C/N were 6 h/2 h and 6. During the three-year operation of the IAS-TFCWs, the effluent concentrations of CODCr, NH4+-N, and TP could comply with Class IV Standard of "Environmental Quality Standards for Surface Water" (GB3838-2002). The mechanism analysis showed that the N removal was effectuated through Fe2+ as the electron donor of Fe(II)-driven the autotrophic denitrifying bacteria to reduce nitrate, while the P removal mainly depended on the adsorption reaction between FeOOH in IAS and phosphate. In conclusion, the stable Fe-N cycle in the IAS-TFCWs achieved simultaneous and efficient N and P removal.
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Affiliation(s)
- Ming Zhou
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China; Henan Yongze Environmental Technology Co., LTD, Zhengzhou 451191, China
| | - Jiashun Cao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Yanhong Lu
- Henan Yongze Environmental Technology Co., LTD, Zhengzhou 451191, China
| | - Lisha Zhu
- Henan Yongze Environmental Technology Co., LTD, Zhengzhou 451191, China
| | - Chao Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
| | - Yantang Wang
- Henan Yongze Environmental Technology Co., LTD, Zhengzhou 451191, China
| | - Liangshan Hao
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Jingyang Luo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | - Hongqiang Ren
- College of Environment, Nanjing University, Nanjing 210093, China
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5
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Bi Z, Zhang Q, Xu X, Yuan Y, Ren N, Lee DJ, Chen C. Perspective on inorganic electron donor-mediated biological denitrification process for low C/N wastewaters. BIORESOURCE TECHNOLOGY 2022; 363:127890. [PMID: 36075347 DOI: 10.1016/j.biortech.2022.127890] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/28/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Nitrate is the most common water environmental pollutant in the world. Inorganic electron donor-mediated denitrification is a typical process with significant advantages in treating low carbon-nitrogen ratio water and wastewater and has attracted extensive research attention. This review summarizes the denitrification processes using inorganic substances, including hydrogen, reductive sulfur compounds, zero-valent iron, and iron oxides, ammonium nitrogen, and other reductive heavy metal ions as electron donors. Aspects on the functional microorganisms, critical metabolic pathways, limiting factors and mathematical modeling are outlined. Also, the typical inorganic electron donor-mediated denitrification processes and their mechanism, the available microorganisms, process enhancing approaches and the engineering potentials, are compared and discussed. Finally, the prospects of developing the next generation inorganic electron donor-mediated denitrification process is put forward.
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Affiliation(s)
- Zhihao Bi
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Quan Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Xijun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Yuan Yuan
- College of Biological Engineering, Beijing Polytechnic, Beijing 10076, China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China; Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China
| | - Duu-Jong Lee
- Department of Mechanical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong; Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-li 32003, Taiwan
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China.
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6
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Yang Y, Ma C, He X, Li J, Li M, Wang J. Calcined Aluminum Sludge as a Heterogeneous Fenton-Like Catalyst for Methylene Blue Degradation by Three-Dimensional Electrochemical System. Electrocatalysis (N Y) 2021. [DOI: 10.1007/s12678-021-00684-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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7
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Gupta RK, Poddar BJ, Nakhate SP, Chavan AR, Singh AK, Purohit HJ, Khardenavis AA. Role of heterotrophic nitrifiers and aerobic denitrifiers in simultaneous nitrification and denitrification process: A non-conventional nitrogen removal pathway in wastewater treatment. Lett Appl Microbiol 2021; 74:159-184. [PMID: 34402087 DOI: 10.1111/lam.13553] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/01/2022]
Abstract
Bacterial species capable of performing both nitrification and denitrification in a single vessel under similar conditions have gained significance in the wastewater treatment scenario considering their unique character of performing the above reactions under heterotrophic and aerobic conditions respectively. Such a novel strategy often referred to as simultaneous nitrification and denitrification (SND) has a tremendous potential in dealing with various wastewaters having low C:N content, considering that the process needs very little or no external carbon source and oxygen supply thus adding to its cost-effective and environmentally friendly nature. Though like other microorganisms, heterotrophic nitrifiers and aerobic denitrifiers convert inorganic or organic nitrogen-containing substances into harmless dinitrogen gas in the wastewater, their ecophysiological role in the global nitrogen cycle is still not yet fully understood. Attempts to highlight the role played by the heterotrophic nitrifiers and aerobic denitrifiers in dealing with nitrogen pollution under various environmental operating conditions will help in developing a mechanistic understanding of the SND process to address the issues faced by the traditional methods of aerobic autotrophic nitrification-anaerobic heterotrophic denitrification.
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Affiliation(s)
- Rakesh Kumar Gupta
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Bhagyashri Jagdishprasad Poddar
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Suraj Prabhakarrao Nakhate
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Atul Rajkumar Chavan
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Ashish Kumar Singh
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Hemant J Purohit
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India
| | - Anshuman Arun Khardenavis
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nagpur, 440020, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
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8
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Yan FL, Wang Y, Wang WH, Zhang H, Zheng YC, Kou XM, Wu SZ, Shao T. Effect of first-stage aeration on treatment of domestic sewage in different hybrid constructed wetlands. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:43402-43416. [PMID: 33834330 DOI: 10.1007/s11356-021-12449-0] [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: 09/15/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Two sets of hybrid constructed wetlands (HCWs) with the first-stage aeration were used to treat actual domestic sewage in this paper, where the effects of three important factors of aeration mode, hydraulic loading rates (HLR), and aeration volume on the removal of pollutants in both HCWs were studied in contrasts. In addition, the pollutant removal efficiency, the contribution of plants, and the characteristics of biofilm in both HCWs were explored. The results of 250-day experiment showed that the TN removal capacity of HCW combining vertical flow CW with horizontal flow CW (VF-HF) was better than HCW's converse combination (HF-VF) in treatingsewage, while the removal efficiency of COD and NH4+-N were similar, and the concentrations of TN and COD in the effluent of VF-HF could successfully meet the National discharge requirements. Compared with the continuous aeration, the intermittent aeration only had a little effect on the removal of COD and NH4+-N, but could improve TN removal performance in both HCWs. Meanwhile, increasing the aeration volume was beneficial to remove NH4+-N but not TN in HCWs. In addition, although the pollutant removal performances in both HCWs were impacted, the removal capacity of TN in VF-HF was only affected a little, when HLR was increased by 50%. The contribution of plants' uptake accounted for about 10% to nitrogen removal and 20% to phosphorus removal in both HCWs. The biomass at the filler surface near the plant rhizosphere was greater than that in the non-rhizosphere zones, and the impact of plant rhizosphere on the nitrification activity of biofilm was significantly greater than that on denitrification activity in both HCWs.
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Affiliation(s)
- Fei-Long Yan
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, China
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Yi Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, China.
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China.
| | - Wen-Huai Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, China
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Heng Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, China
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Yu-Cong Zheng
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, China
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China
| | - Xiao-Mei Kou
- Power China-Northwest Engineering Corporation Limited, Xi'an, 710065, China
| | - Shi-Zhang Wu
- Power China-Northwest Engineering Corporation Limited, Xi'an, 710065, China
| | - Tian Shao
- Power China-Northwest Engineering Corporation Limited, Xi'an, 710065, China
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9
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Zhao C, Xu J, Shang D, Zhang Y, Zhang J, Xie H, Kong Q, Wang Q. Application of constructed wetlands in the PAH remediation of surface water: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 780:146605. [PMID: 34030309 DOI: 10.1016/j.scitotenv.2021.146605] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) pose adverse risks to ecosystems and public health because of their carcinogenicity and mutagenicity. As such, the extensive occurrence of PAHs represents a worldwide concern that requires urgent solutions. Wastewater treatment plants are not, however, designed for PAH removal and often become sources of the PAHs entering surface waters. Among the technologies applied in PAH remediation, constructed wetlands (CWs) exhibit several cost-effective and eco-friendly advantages, yet a systematic examination of the application and success of CWs for PAH remediation is missing. This review discusses PAH occurrence, distribution, and seasonal patterns in surface waters during the last decade to provide baseline information for risk control and further treatment. Furthermore, based on the application of CWs in PAH remediation, progress in understanding and optimising PAH-removal mechanisms is discussed focussing on sediments, plants, and microorganisms. Wetland plant traits are key factors affecting the mechanisms of PAH removal in CWs, including adsorption, uptake, phytovolatilization, and biodegradation. The physico-chemical characteristics of PAHs, environmental conditions, wetland configuration, and operation parameters are also reviewed as important factors affecting PAH removal efficiency. Whilst significant progress has been made, several key problems need to be addressed to ensure the success of large-scale CW projects. These include improving performance in cold climates and addressing the toxic threshold effects of PAHs on wetland plants. Overall, this review provides future direction for research on PAH removal using CWs and their large-scale operation for the treatment of PAH-contaminated surface waters.
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Affiliation(s)
- Congcong Zhao
- College of Geography and Environment, Shandong Normal University, Jinan 250014, China
| | - Jingtao Xu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Dawei Shang
- College of Geography and Environment, Shandong Normal University, Jinan 250014, China
| | - Yanmeng Zhang
- College of Geography and Environment, Shandong Normal University, Jinan 250014, China
| | - Jian Zhang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Technology, Shandong University, Jinan 250100, China.
| | - Huijun Xie
- Environment Research Institute, Shandong University, Jinan 250100, China
| | - Qiang Kong
- College of Geography and Environment, Shandong Normal University, Jinan 250014, China
| | - Qian Wang
- College of Geography and Environment, Shandong Normal University, Jinan 250014, China
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10
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Ren B, Wang T, Zhao Y. Two-stage hybrid constructed wetland-microbial fuel cells for swine wastewater treatment and bioenergy generation. CHEMOSPHERE 2021; 268:128803. [PMID: 33143898 DOI: 10.1016/j.chemosphere.2020.128803] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/24/2020] [Accepted: 10/27/2020] [Indexed: 06/11/2023]
Abstract
A newly emerged alum sludge-based hybrid constructed wetland-microbial fuel cells (CW-MFCs), i.e. vertical upflow CW coupled MFC as 1st stage and horizontal subsurface flow CW coupled MFC as 2nd stage (VFCW-MFC + HSSFCW-MFC), was firstly developed for swine wastewater treatment and electricity generation. Swine wastewater and multi-set air-cathodes were applied to investigate the pollutants removal behavior and the power production. Six-month trial suggested that the overall removal efficiency of SS, COD, NH4+-N, NO3--N, TN, TP and PO43--P was 76 ± 12.4, 72 ± 7.4, 59 ± 28.3, 69 ± 25.6, 47 ± 19.7, 85 ± 9.5 and 88 ± 8.7%, respectively. The two stages hybrid system (VFCW-MFC + HSSFCW-MFC) continuously generated electrical power with average voltages of 0.44 ± 0.09 and 0.34 ± 0.09 V, and power densities of 33.3 ± 13.81 and 9.0 ± 2.5 mW/m³ in 1st and 2nd stage, respectively. The average net energy recovery (NER) of 1st stage and 2nd stage is in turn 0.91 ± 0.16 and 2.76 ± 0.70 Wh/kg·COD. It indicates that the hybrid CW-MFCs has higher removal efficiency than single stage CW-MFC, while 1st stage plays the major role both in pollutants removal and power generation.
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Affiliation(s)
- Baiming Ren
- Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an, 710054, PR China; School of Water and Environment, Chang'an University, Xi'an, 710054, PR China; Centre for Water Resources Research, School of Civil Engineering, University College Dublin, Belfield, Dublin 4, Ireland
| | - Tongyue Wang
- Centre for Water Resources Research, School of Civil Engineering, University College Dublin, Belfield, Dublin 4, Ireland; School of Science,Xi'an University of Architecture and Technology,No. 13, Middle Yanta Road, Beilin District, Xi'an, 710055, PR China
| | - Yaqian Zhao
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an, 710048, PR China.
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11
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Gonzalo OG, Ruiz I, Soto M. Effect of different bypass rates and unit area ratio in hybrid constructed wetlands. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:40355-40369. [PMID: 32666454 DOI: 10.1007/s11356-020-09982-9] [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: 03/19/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
This study presents the performance of a hybrid constructed wetland (Bp(VF + HF)2:1) system which consists of an unsaturated vertical flow (VF) unit followed by a saturated down-flow unit simulating horizontal flow (HF) with HF/VF area ratio of 0.5 and influent bypass to the HF unit. Treating synthetic wastewater simulating municipal wastewater, optimum total nitrogen (TN) removal (57%) was reached at 39% bypass and surface loading rate (SLR) of 33 g BOD5/m2 day and 9.7 g TN/m2 day (overall system). On the other hand, treating actual municipal wastewater, the system reached 63% TN removal at 30% bypass and SLR of 18 g BOD5/m2 day and 4.7 g TN/m2 day. Surface removal rates reached 5.5 and 3.0 g TN/m2 day for synthetic and municipal wastewater. Surface nitrification rate in the VF unit was in the range of 5.0-7.4 and 3.6-3.8 g N/m2 day for synthetic and municipal wastewater, respectively, indicating a large effect of wastewater characteristics on the nitrification process. Infiltration rate in the VF unit remained high and far from clogging risk. Overall greenhouse gas emissions were 0.11 (N2O) and 0.41 (CH4) g/m2 day which corresponded to emissions factors (relative to total organic carbon and TN influent) of 0.7% (N2O) and 3.6% (CH4). Compared with a similar system with a different HF/VF area ratio of 2.0, organic matter and nitrogen removal efficiency was similar, but surface removal rates were about 3 times higher.
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Affiliation(s)
- Omar Gael Gonzalo
- Department of Chemistry, University of A Coruña, Rúa da Fraga 10, 15008, A Coruña, Galiza, Spain
| | - Isabel Ruiz
- Department of Chemistry, University of A Coruña, Rúa da Fraga 10, 15008, A Coruña, Galiza, Spain
| | - Manuel Soto
- Department of Chemistry, University of A Coruña, Rúa da Fraga 10, 15008, A Coruña, Galiza, Spain.
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12
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Hu Y, Wu G, Li R, Xiao L, Zhan X. Iron sulphides mediated autotrophic denitrification: An emerging bioprocess for nitrate pollution mitigation and sustainable wastewater treatment. WATER RESEARCH 2020; 179:115914. [PMID: 32413614 DOI: 10.1016/j.watres.2020.115914] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 03/16/2020] [Accepted: 05/02/2020] [Indexed: 05/09/2023]
Abstract
Iron sulphides, mainly in the form of mackinawite (FeS), pyrrhotite (Fe1-xS, x = 0-0.125) and pyrite (FeS2), are the most abundant sulphide minerals and can be oxidized under anoxic and circumneutral pH conditions by chemoautotrophic denitrifying bacteria to reduce nitrate to N2. Iron sulphides mediated autotrophic denitrification (ISAD) represents an important natural attenuation process of nitrate pollution and plays a pivotal role in linking nitrogen, sulphur and iron cycles in a variety of anoxic environments. Recently, it has emerged as a promising bioprocess for nutrient removal from various organic-deficient water and wastewater, due to its specific advantages including high denitrification capacity, simultaneous nitrogen and phosphorus removal, self-buffering properties, and fewer by-products generation (sulphate, waste sludge, N2O, NH4+, etc.). This paper provides a critical overview of fundamental and engineering aspects of ISAD, including the theoretical knowledge (biochemistry, and microbial diversity), its natural occurrence and engineering applications. Its potential and limitations are elucidated by summarizing the key influencing factors including availability of iron sulphides, low denitrification rates, sulphate emission and leaching heavy metals. This review also put forward two key questions in the mechanism of anoxic iron sulphides oxidation, i.e. dissolution of iron sulphides and direct substrates for denitrifiers. Finally, its prospects for future sustainable wastewater treatment are highlighted. An iron sulphides-based biotechnology towards next-generation wastewater treatment (NEO-GREEN) is proposed, which can potentially harness bioenergy in wastewater, incorporate resources (P and Fe) recovery, achieve simultaneous nutrient and emerging contaminants removal, and minimize waste sludge production.
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Affiliation(s)
- Yuansheng Hu
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland; Ryan Institute, National University of Ireland, Galway, Ireland
| | - Guangxue Wu
- Institute of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China
| | - Ruihua Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163# Xianlin Avenue, Nanjing, 210023, China
| | - Liwen Xiao
- Department of Civil, Structural and Environmental Engineering, Trinity College Dublin, Dublin 2, Ireland
| | - Xinmin Zhan
- Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland; Ryan Institute, National University of Ireland, Galway, Ireland; MaREI Centre for Marine and Renewable Energy, Ireland.
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13
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Wang Y, Shen L, Wu J, Zhong F, Cheng S. Step-feeding ratios affect nitrogen removal and related microbial communities in multi-stage vertical flow constructed wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137689. [PMID: 32169643 DOI: 10.1016/j.scitotenv.2020.137689] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 02/25/2020] [Accepted: 03/01/2020] [Indexed: 06/10/2023]
Abstract
Step-feeding (SF) strategies have been adopted in several types of constructed wetlands (CWs) to enhance nitrogen (N) removal. However, it is unclear how SF affects the N-transforming bacterial communities in CWs. Herein, four multi-stage vertical flow constructed wetlands (MS-VFCWs), each including three vertical flow stages (stage 1-3), were operated under different SF ratios (0%, 10%, 20% and 30%) in the stage 2. The physicochemical influent and effluent parameters, i.e., redox potential (ORP), pH value, chemical oxygen demand (COD), total nitrogen (TN), ammonia (NH4+-N), nitrate (NO3--N), and nitrite (NO2--N), free-ammonia (FA) concentration, COD/TN ratio, as well as the abundance, structure, and activity of N-transforming bacteria were investigated. Results showed that N removal in a multi-stage vertical flow constructed wetland in the absence of SF was 45.0 ± 7.74%. Alternatively, a combined SF ratio of 20% increased N removal to 61.7% ± 4.50%, accounting for a 37.1% increase compared to the SF ratio of 0%. In the microbial community, FA was determined to be the primary physicochemical parameter governing nitrification processes in MS-VFCWs. Further, partial nitrification processes played an important role in ammonium removal during stage 1, while ammonia-oxidizing archaea were major contributors to ammonium removal in stage 3. Furthermore, abundance of nitrite reductase genes (nirS, nirK) and relative abundance of denitrifying bacteria increased with increasing SF ratio; while the nirS/nirK ratio and the alpha diversity of nirK denitrifiers were significantly affected by SF ratios, and the influent NO3--N concentration was related to a shift in denitrifier composition toward strains containing the nirS gene. Autotrophic (e.g., Thiobacillus, Sulfurimonas, Arenimonas, Gallionella and Methyloparacoccus) and facultative chemolithoautotrophic (e.g., Pseudomonas and Denitratisoma) denitrifying bacteria were enriched in stage 2. Hence, the synergy between heterotrophic and autotrophic denitrifying bacteria promoted excellent N removal efficiency with a low COD/TN ratio.
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Affiliation(s)
- Ying Wang
- Tongji University, College of Environmental Science and Engineering, Key Laboratory of Yangtze River Water Environment, Ministry of Education, 200092, PR China
| | - Linya Shen
- Tongji University, College of Environmental Science and Engineering, Key Laboratory of Yangtze River Water Environment, Ministry of Education, 200092, PR China
| | - Juan Wu
- Tongji University, College of Environmental Science and Engineering, Key Laboratory of Yangtze River Water Environment, Ministry of Education, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; Shanghai Engineering Research Center of Landscape Water Environment, Shanghai 200031, PR China.
| | - Fei Zhong
- Nantong University, School of Life Science, Nantong 226019, PR China
| | - Shuiping Cheng
- Tongji University, College of Environmental Science and Engineering, Key Laboratory of Yangtze River Water Environment, Ministry of Education, 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; Shanghai Engineering Research Center of Landscape Water Environment, Shanghai 200031, PR China.
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14
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Liu C, Li X, Yang Y, Fan X, Tan X, Yin W, Liu Y, Zhou Z. Double-layer substrate of shale ceramsite and active alumina tidal flow constructed wetland enhanced nitrogen removal from decentralized domestic sewage. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:135629. [PMID: 31761355 DOI: 10.1016/j.scitotenv.2019.135629] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/16/2019] [Accepted: 11/17/2019] [Indexed: 06/10/2023]
Abstract
This study explored the application of shale ceramsite (SC) overlaid onto active alumina (AA) to function as a double-layer substrate in tidal flow constructed wetland (TFCW, SC-AA-TFCW) for decentralized domestic sewage treatment. This was compared to AA or SC substrate alone (AA-TFCW or SC-TFCW) for nitrogen removal, variation of dissolved oxygen and porosity in TFCWs, as well as structure of bacterial communities at varied hydraulic load (HL) of 0.204-2.448 m3/m2 d with time ratio of the wet and dry phase of 3:1. The results demonstrate that SC-AA-TFCW removed 86% NH4+-N and 79% total nitrogen at HL of 0.612 m3/m2 d, which was better than AA-TFCW(76%) or SC-TFCW(49%). The higher nitrogen removal performance in SC-AA-TFCW was mainly attributed to enhanced oxygen transportation due to non-uniform flow field and irregular gap distribution in layered structure, as well as less pore blockage during long-term operation. Denitrifying bacteria including Dechloromonas, Acidovorax, Chryseobacterium and Thermomonas species took up 32% of the microbiome in SC-AA-TFCW, which was higher than in AA-TFCW (17%) and SC-TFCW (7.7%). This study highlighted the importance of layered structures and determined an optimal HL of TFCW to achieve an efficient and stable nitrogen removal for domestic sewage treatment.
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Affiliation(s)
- Changjian Liu
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xing Li
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
| | - Yanling Yang
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
| | - Xiaoyan Fan
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xu Tan
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Wenchao Yin
- China Architecture Design Group, Beijing 100044, China.
| | - Yongwang Liu
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China; China Architecture Design Group, Beijing 100044, China
| | - Zhiwei Zhou
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, PR China.
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15
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Zheng X, Zhuang LL, Zhang J, Li X, Zhao Q, Song X, Dong C, Liao J. Advanced oxygenation efficiency and purification of wastewater using a constant partially unsaturated scheme in column experiments simulating vertical subsurface flow constructed wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:135480. [PMID: 31740061 DOI: 10.1016/j.scitotenv.2019.135480] [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: 07/27/2019] [Revised: 11/08/2019] [Accepted: 11/09/2019] [Indexed: 06/10/2023]
Abstract
The presence of sufficient dissolved oxygen (DO) in a constructed wetland (CW) is vital to the process of removing ammonia nitrogen and organics from wastewater. To achieve total nitrogen removal, which is characterised by enhanced ammonia nitrogen removal, this study offers an efficient strategy to increase the oxygen supply by establishing constant unsaturated zones and baffles in simulating constructed wetlands (SCWs). Henceforth, this strategy is addressed as a partially unsaturated SCW. A centrally located high tube was set up inside the wetland to create an unsaturated zone at a higher level. The effectiveness of the unsaturated zone to supplement the oxygen content was evaluated by comparing with controls (an unaerated SCW and an aerated SCW). The results show the chemical oxygen demand removal rate (85 ± 6%) in the partially unsaturated SCW was equivalent to that in the aerated SCW (83 ± 6%), while the ammonia nitrogen removal rate was 11 times higher compared to that of the unaerated SCW. The removal potential of the partially unsaturated SCW under different HRT (hydraulic retention time)s (12, 24, and 36 h) was examined, and the 36 h-SCW performed the best in the removal of organics and nitrogen. The mechanisms behind the unsaturated zone strategy were studied by analysing water and microbe samples along the pathway. The results from the water quality indicators and the quantitative polymerase chain reactions along the pathway showed the unsaturated zone contributed to the removal of primary organics and ammonia nitrogen. The superior performance of unsaturated zone strategy was discussed further using the enrichment of ammonia-oxidising bacteria, mass of oxygen uptake, and baffle design. The results indicate that the amoA gene/16s rRNA gene abundance ratio and the oxygen uptake (336 ± 44 g m-3 d-1) in the partially unsaturated SCW was higher than that observed in the two controls.
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Affiliation(s)
- Xinhui Zheng
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
| | - Lin-Lan Zhuang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China.
| | - Jian Zhang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
| | - Xiangzheng Li
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
| | - Qian Zhao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
| | - Xiran Song
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
| | - Cheng Dong
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
| | - Jiayi Liao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
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16
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Zhuang LL, Yang T, Zhang J, Li X. The configuration, purification effect and mechanism of intensified constructed wetland for wastewater treatment from the aspect of nitrogen removal: A review. BIORESOURCE TECHNOLOGY 2019; 293:122086. [PMID: 31495460 DOI: 10.1016/j.biortech.2019.122086] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 05/10/2023]
Abstract
Constructed wetland (CW) for wastewater treatment has attracted increasing attention. In this review, the system configuration optimization, purification effect and general mechanisms of nitrogen removal in CW are systematically summarized and discussed. Ammonia oxidation is a crucial and primary process for total nitrogen (TN) removal in domestic or livestock wastewater treatment. Aeration, waterdrop influent and tidal operation are three main methods to strengthen the oxygen supplement and nitrification process in CW. Aeration significantly increases the ammonia removal rate (almost 100%), followed by the removal of chemical oxygen demand (COD) and TN. Solid carbon source, iron and anode material can be filled as electron donor for the denitrification process. The co-adjustment of oxygen and carbon/electron donor can form different conditions for different nitrogen removal pathways (e.g. the simultaneous nitrification-denitrification, the partial nitrification-denitrification and the anammox process), and achieve the optimal removal of nitrogen.
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Affiliation(s)
- Lin-Lan Zhuang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
| | - Ting Yang
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Jian Zhang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China.
| | - Xiangzheng Li
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, China
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17
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Wei CJ, Wu WZ. Performance of single-pass and by-pass multi-step multi-soil-layering systems for low-(C/N)-ratio polluted river water treatment. CHEMOSPHERE 2018; 206:579-586. [PMID: 29778083 DOI: 10.1016/j.chemosphere.2018.05.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 04/03/2018] [Accepted: 05/06/2018] [Indexed: 06/08/2023]
Abstract
Two kinds of hybrid two-step multi-soil-layering (MSL) systems loaded with different filter medias (zeolite-ceramsite MSL-1 and ceramsite-red clay MSL-2) were set-up for the low-(C/N)-ratio polluted river water treatment. A long-term pollutant removal performance of these two kinds of MSL systems was evaluated for 214 days. By-pass was employed in MSL systems to evaluate its effect on nitrogen removal enhancement. Zeolite-ceramsite single-pass MSL-1 system owns outstanding ammonia removal capability (24 g NH4+-Nm-2d-1), 3 times higher than MSL-2 without zeolite under low aeration rate condition (0.8 × 104 L m-2.h-1). Aeration rate up to 1.6 × 104 L m-2.h-1 well satisfied the requirement of complete nitrification in first unit of both two MSLs. However, weak denitrification in second unit was commonly observed. By-pass of 50% influent into second unit can improve about 20% TN removal rate for both MSL-1 and MSL-2. Complete nitrification and denitrification was achieved in by-pass MSL systems after addition of carbon source with the resulting C/N ratio up to 2.5. The characters of biofilms distributed in different sections inside MSL-1 system well illustrated the nitrogen removal mechanism inside MSL systems. Two kinds of MSLs are both promising as an appealing nitrifying biofilm reactor. Recirculation can be considered further for by-pass MSL-2 system to ensure a complete ammonia removal.
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Affiliation(s)
- Cai-Jie Wei
- Department of Environmental Science, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Wei-Zhong Wu
- Department of Environmental Science, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
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18
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Liu X, Zhang Y, Li X, Fu C, Shi T, Yan P. Effects of influent nitrogen loads on nitrogen and COD removal in horizontal subsurface flow constructed wetlands during different growth periods of Phragmites australis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 635:1360-1366. [PMID: 29710589 DOI: 10.1016/j.scitotenv.2018.03.260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 06/08/2023]
Abstract
Horizontal subsurface constructed wetlands (HSSF-CWs) planted with Phragmites australis were established to examine the effect of influent nitrogen loads on the removal efficiencies of nitrogen and chemical oxygen demand (COD) during different plant growth periods of plants. Under low influent nitrogen loads, most of the dissolved oxygen was consumed during the oxidation of organic matter in the wetland systems, and a dissimilatory nitrate reduction to ammonium (DNRA) may have occurred in HSSF-CWs when excessive amounts of organic matter were present, which limited the nitrification of ammonium nitrogen (NH4-N) and hindered the NH4-N removal. An increase in the influent nitrogen loads resulted in an enhancement of the removal efficiencies of NH4-N, nitrate nitrogen (NO3-N) and total nitrogen (TN) during the same growth period, except for NO3-N under the highest influent nitrogen loads, whereas fluctuations occurred for the COD removal efficiency. Compared with the rapid growth period, the removal efficiency of NH4-N, NO3-N and TN increased during the mature period; however, the COD removal efficiency decreased. The change of COD: N (COD:TN in wastewater) ratios with retention times indicated the sufficiency or deficiency of organic matter as an electron donor in the wetland systems. The changes in the pH value and oxidation-reduction potential (ORP) indirectly demonstrated that many factors affected the effluent pH value and ORP, such as retention time, influent loads, plants and wetland substrate, and microorganisms. In this study, the changes of ORP also illustrated that the dissolved oxygen concentrations decreased with increasing retention time in the HSSF-CWs; however, no significant increase in the ORP was observed during the two growth periods.
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Affiliation(s)
- Xuelan Liu
- Poultry Institute, Shangdong Academy of Agricultural Science, Jinan 250023, PR China
| | - Yan Zhang
- Poultry Institute, Shangdong Academy of Agricultural Science, Jinan 250023, PR China.
| | - Xinhua Li
- Shandong Institute of Agricultural Sustainable Development, Jinan 250100, PR China
| | - Chunyan Fu
- Poultry Institute, Shangdong Academy of Agricultural Science, Jinan 250023, PR China
| | - Tianhong Shi
- Poultry Institute, Shangdong Academy of Agricultural Science, Jinan 250023, PR China
| | - Peipei Yan
- Poultry Institute, Shangdong Academy of Agricultural Science, Jinan 250023, PR China
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19
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Zhao X, Hu Y, Zhao Y, Kumar L. Achieving an extraordinary high organic and hydraulic loadings with good performance via an alternative operation strategy in a multi-stage constructed wetland system. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:11841-11853. [PMID: 29446020 DOI: 10.1007/s11356-018-1464-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/01/2018] [Indexed: 06/08/2023]
Abstract
In this study, a high organic loading rate of 58-146 g BOD5/m2 day with a hydraulic loading rate (HLR) of 1.63 m3/m2 day and retention time (RT) of 16 h was achieved to maximize the treatment capacity of a four-stage alum sludge-based constructed wetland (CW) system. An alternative operation strategy, i.e., the first stage anaerobic up-flow and the remaining stage tidal flow with effluent recirculation, was investigated to achieve the goal with good treatment performance of 82% COD, 91% BOD5, 92% SS, 94% NH4-N, and 82% TN removal. Two kinetic models, i.e., first-order model and Monod plus continuous stirred-tank reactor (CSTR) flow model, were employed for predicting the removal dynamics. The results showed that the tidal flow strategy enhances oxygen transport and diffusion, thus improving reduction of organics and NH4-N. Effluent recirculation could further increase elimination of organics by extending the interaction time and also benefit the denitrification process. In addition, denitrification could be further enhanced by anaerobic up-flow in the first stage.
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Affiliation(s)
- Xiaohong Zhao
- Key Laboratory of Water Supply and Drainage, Ministry of Housing and Urban-Rural Development, Chang'an University, Xi'an, 710061, People's Republic of China
| | - Yuansheng Hu
- Key Laboratory of Urban Stormwater System and Water Environment/R&D Centre for Sustainable Wastewater Treatment, Beijing University of Civil Engineering and Architecture, Ministry of Education, Beijing, 100044, People's Republic of China
| | - Yaqian Zhao
- Key Laboratory of Water Supply and Drainage, Ministry of Housing and Urban-Rural Development, Chang'an University, Xi'an, 710061, People's Republic of China.
- UCD Dooge Centre for Water Resources Research, School of Civil Engineering, University College Dublin, Newstead, Belfield, Dublin 4, Ireland.
| | - Lordwin Kumar
- UCD Dooge Centre for Water Resources Research, School of Civil Engineering, University College Dublin, Newstead, Belfield, Dublin 4, Ireland
- Department of Soil Water Land Engineering and Management, Vaugh School of Agricultural Engineering and Technology, Sam Higginbottom Institute of Agriculture, Technology & Sciences, Allahabad, India
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20
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Zhang X, Hu Z, Zhang J, Fan J, Ngo HH, Guo W, Zeng C, Wu Y, Wang S. A novel aerated surface flow constructed wetland using exhaust gas from biological wastewater treatment: Performance and mechanisms. BIORESOURCE TECHNOLOGY 2018; 250:94-101. [PMID: 29156370 DOI: 10.1016/j.biortech.2017.08.172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 08/26/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
In this study, a novel aerated surface flow constructed wetland (SFCW) using exhaust gas from biological wastewater treatment was investigated. Compared with un-aerated SFCW, the introduction of exhaust gas into SFCW significantly improved NH4+-N, TN and COD removal efficiencies by 68.30 ± 2.06%, 24.92 ± 1.13% and 73.92 ± 2.36%, respectively. The pollutants removal mechanism was related to the microbial abundance and the highest microbial abundance was observed in the SFCW with exhaust gas because of the introduction of exhaust gas from sequencing batch reactor (SBR), and thereby optimizing nitrogen transformation processes. Moreover, SFCW would significantly mitigate the risk of exhaust gas pollution. SFCW removed 20.00 ± 1.23%, 34.78 ± 1.39%, and 59.50 ± 2.33% of H2S, NH3 and N2O in the exhaust gas, respectively. And 31.32 ± 2.23% and 32.02 ± 2.86% of bacterial and fungal aerosols in exhaust gas were also removed through passing SFCW, respectively.
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Affiliation(s)
- Xinwen Zhang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, Shandong, PR China
| | - Zhen Hu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, Shandong, PR China
| | - Jian Zhang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, Shandong, PR China.
| | - Jinlin Fan
- National Engineering Laboratory of Coal-Fired Pollutants Emission Reduction, Shandong University, Jinan 250061, PR China
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Wenshan Guo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Chujun Zeng
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, Shandong, PR China
| | - Yiwen Wu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, Shandong, PR China
| | - Siyuan Wang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, Shandong, PR China
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21
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Using a Backpropagation Artificial Neural Network to Predict Nutrient Removal in Tidal Flow Constructed Wetlands. WATER 2018. [DOI: 10.3390/w10010083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Torrijos V, Ruiz I, Soto M. Effect of step-feeding on the performance of lab-scale columns simulating vertical flow-horizontal flow constructed wetlands. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:22649-22662. [PMID: 28812288 DOI: 10.1007/s11356-017-9925-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
The effect of step-feeding (untreated wastewater by-pass) on the performance of lab-scale columns simulating a hybrid vertical flow (VF)-horizontal flow (HF) constructed wetland (CW) system was studied. Step-feeding strategies have been adopted in several kinds of CW, but this is the first report about the use of step-feeding in VF + HF hybrid systems treating domestic wastewater. Applied loading rates were 7-11 g BOD5/m2 day and 2.1-3.4 g TN/m2 day (overall system). Removal efficiency reached 98% TSS and COD and 99% BOD5 on average, whilst a 50% by-pass improved TN removal from 31 to 50%. Maximum surface nitrification rate (5.5 g N/m2 day) was obtained in VF unit, whilst maximum denitrification rate (1.8 g N/m2 day) was observed in HF unit. Referred to the overall system, maximum surface nitrification and denitrification rates were 2.2 and 1.6 g N/m2 day, respectively. However, potential nitrifying and denitrifying activities (batch assays) were 15.0 and 58.9 g N/m2 day, respectively. Even at 50% by-pass, operational conditions in HF unit (dissolved oxygen, redox, COD/TN ratio) were not suitable enough for denitrification. However, methane emissions were not observed and nitrous oxide emissions were relatively low.
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Affiliation(s)
- Verónica Torrijos
- Department of Chemistry, University of A Coruña, Rúa da Fraga 10, 15008, A Coruña, Galiza, Spain
| | - Isabel Ruiz
- Department of Chemistry, University of A Coruña, Rúa da Fraga 10, 15008, A Coruña, Galiza, Spain
| | - Manuel Soto
- Department of Chemistry, University of A Coruña, Rúa da Fraga 10, 15008, A Coruña, Galiza, Spain.
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Hou J, Xia L, Ma T, Zhang Y, Zhou Y, He X. Achieving short-cut nitrification and denitrification in modified intermittently aerated constructed wetland. BIORESOURCE TECHNOLOGY 2017; 232:10-17. [PMID: 28214440 DOI: 10.1016/j.biortech.2017.02.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 02/04/2017] [Accepted: 02/08/2017] [Indexed: 06/06/2023]
Abstract
This study aim to enhance nitrogen removal performance via shifting nitrogen removal pathway from nitrate to nitrite pathway. It was demonstrated that nitrite pathway was successfully and stably achieved in CWs by using modified intermittent aeration control with aeration 20min/non-aeration 100min and reducing DO concentration during aeration, nitrite in the effluent could accumulate to over 70% of the total oxidized nitrogen. Q-PCR analysis showed that nitrifying microbial communities were optimized under the alternating anoxic and aerobic conditions, ammonia oxidizing bacteria increased from 7.15×106 to 8.99×106copies/g, while nitrite oxidizing bacteria decreased approximately threefold after 234days operation. Most importantly, high nitrogen removal efficiency with ammonium removal efficiency of 94.6%, and total nitrogen removal efficiency of 82.6% could be achieved via nitrite pathway even under carbon limiting conditions. In comparison to the nitrate pathway, the nitrite pathway could improve the TN removal by about 55%.
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Affiliation(s)
- Jie Hou
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China
| | - Ling Xia
- School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Tao Ma
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Yiqing Zhang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Yiyong Zhou
- The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Xugang He
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
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24
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Gonzalo OG, Ruiz I, Soto M. Integrating pretreatment and denitrification in constructed wetland systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 584-585:1300-1309. [PMID: 28189310 DOI: 10.1016/j.scitotenv.2017.01.217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/30/2017] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
The aim of this work was to study the operational characteristics and the efficiency of a compact constructed wetland system for municipal wastewater treatment that integrates denitrification in the pre-treatment unit. The proposed system was simulated by two units in series with effluent recirculation, the first one being an anoxic digester, conceived as a hydrolytic up flow sludge bed for solids hydrolysis and denitrification, and the second one a sand column that simulated the operation of a vertical flow constructed wetland. The hybrid system consisted of two small columns of 4 and 10.2cm in diameter (anoxic digester and vertical flow unit, respectively). The unplanted system was operated successively with synthetic and real municipal wastewater over a period of 136days. Hydraulic loading rate ranged from 212 to 318mm/day and surface loading rate from 122 to 145g/m2·day of chemical oxygen demand and 10-15g/m2·day of total nitrogen for the overall system. The overall system reached removals of 91% to 99% for total suspended solids, chemical oxygen demand and biochemical oxygen demand whilst total nitrogen removal ranged from 43% to 61%. In addition to suspended solids removal (up to 78%), the anoxic digester provided high denitrification rates (3-12gN/m2·day) whilst the vertical flow unit provided high nitrification rates (8-15gN/m2·day). Organic matter was mainly removed in the anoxic digester (63-82% chemical oxygen demand) and used for denitrification. Final effluent concentration was lower for ammonia (7.4±2.4mgN/L on average) than for nitrate (19.8±4.4mgN/L), denitrification appearing as the limiting step in nitrogen removal in the system. CH4 or N2O emissions were not detected in any of the units of the system indicating very low greenhouse gas emissions.
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Affiliation(s)
- O G Gonzalo
- Department of Physical Chemistry and Chemical Engineering l, University of A Coruña, Rúa da Fraga 10, 15008 A Coruña, Spain.
| | - I Ruiz
- Department of Physical Chemistry and Chemical Engineering l, University of A Coruña, Rúa da Fraga 10, 15008 A Coruña, Spain.
| | - M Soto
- Department of Physical Chemistry and Chemical Engineering l, University of A Coruña, Rúa da Fraga 10, 15008 A Coruña, Spain.
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25
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Patil S, Chakraborty S. Effects of step-feeding and intermittent aeration on organics and nitrogen removal in a horizontal subsurface flow constructed wetland. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2017; 52:403-412. [PMID: 27973979 DOI: 10.1080/10934529.2016.1262608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effect of step feed strategy and intermittent aeration on removal of chemical oxygen demand (COD) and nitrogen was investigated in a laboratory scale horizontal subsurface flow constructed wetland (HSSFCW). Wetland was divided into four zones along the length (zone I to IV), and influent was introduced into first and third zones by step feeding. Continuous study was carried out in four phases. In phases I to III, 30% of influent was bypassed to zone III for denitrification along with organics removal. Intermittent aeration was provided only in zone II at 2.5 L/min for 4 h/day, during phases II, III and IV. In phase I, 87% COD and 43% NH4+-N (ammonia-nitrogen) removal were obtained from influents of 331 and 30 mg/L, respectively. In phase II study, external aeration resulted in 97% COD and 71% NH4+-N removal in the wetland. In phase IV, 40% of feed was delivered to zone III. Higher supply of organic in zone III resulted in higher denitrification, and total nitrogen removal rate increased to 70% from 56%. In the final effluent, concentration of NO3--N was 9-11 mg/L in phase I to III and decreased to 4 mg/L in phase IV. Batch study showed that COD and NH4+-N removal followed first order kinetics in different zones of wetland.
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Affiliation(s)
- Sagar Patil
- a Department of Civil Engineering , Indian Institute of Technology Guwahati , Assam , India
| | - Saswati Chakraborty
- a Department of Civil Engineering , Indian Institute of Technology Guwahati , Assam , India
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26
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Torrijos V, Gonzalo OG, Trueba-Santiso A, Ruiz I, Soto M. Effect of by-pass and effluent recirculation on nitrogen removal in hybrid constructed wetlands for domestic and industrial wastewater treatment. WATER RESEARCH 2016; 103:92-100. [PMID: 27441816 DOI: 10.1016/j.watres.2016.07.028] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 07/09/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
Hybrid constructed wetlands (CWs) including subsurface horizontal flow (HF) and vertical flow (VF) steps look for effective nitrification and denitrification through the combination of anaerobic/anoxic and aerobic conditions. Several CW configurations including several configurations of single pass systems (HF + HF, VF + VF, VF + HF), the Bp(VF + HF) arrangement (with feeding by-pass) and the R(HF + VF) system (with effluent recirculation) were tested treating synthetic domestic wastewater. Two HF/VF area ratios (AR) were tested for the VF + HF and Bp(VF + HF) systems. In addition, a R(VF + VF) system was tested for the treatment of a high strength industrial wastewater. The percentage removal of TSS, COD and BOD5 was usually higher than 95% in all systems. The single pass systems showed TN removal below the threshold of 50% and low removal rates (0.6-1.2 g TN/m(2) d), except the VF + VF system which reached 63% and 3.5 g TN/m(2) d removal but only at high loading rates. Bp(VF + HF) systems required by-pass ratios of 40-50% and increased TN removal rates to approximately 50-60% in a sustainable manner. Removal rates depended on the AR value, increasing from 1.6 (AR 2.0) to 5.2 g TN/m(2) d (AR 0.5), both working with synthetic domestic wastewater. On real domestic wastewater the Bp (VF + HF) (AR 0.5 and 30% by-pass) reached 2.5 g TN/m(2) d removal rate. Effluent recirculation significantly improved the TN removal efficiency and rate. The R(HF + VF) system showed stable TN removals of approximately 80% at loading rates ranging from 2 to 8 g TN/m(2) d. High TN removal rates (up to 73% TN and 8.4 g TN/m(2) d) were also obtained for the R(VF + VF) system treating industrial wastewater.
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Affiliation(s)
- V Torrijos
- Department of Physical Chemistry and Chemical Engineering I, University of A Coruña, Rúa da Fraga 10, A Coruña 15008, Galiza, Spain
| | - O G Gonzalo
- Department of Physical Chemistry and Chemical Engineering I, University of A Coruña, Rúa da Fraga 10, A Coruña 15008, Galiza, Spain
| | - A Trueba-Santiso
- Department of Physical Chemistry and Chemical Engineering I, University of A Coruña, Rúa da Fraga 10, A Coruña 15008, Galiza, Spain
| | - I Ruiz
- Department of Physical Chemistry and Chemical Engineering I, University of A Coruña, Rúa da Fraga 10, A Coruña 15008, Galiza, Spain
| | - M Soto
- Department of Physical Chemistry and Chemical Engineering I, University of A Coruña, Rúa da Fraga 10, A Coruña 15008, Galiza, Spain.
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27
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Wu H, Fan J, Zhang J, Ngo HH, Guo W, Liang S, Hu Z, Liu H. Strategies and techniques to enhance constructed wetland performance for sustainable wastewater treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:14637-14650. [PMID: 26268626 DOI: 10.1007/s11356-015-5151-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/03/2015] [Indexed: 06/04/2023]
Abstract
Constructed wetlands (CWs) have been used as an alternative to conventional technologies for wastewater treatment for more than five decades. Recently, the use of various modified CWs to improve treatment performance has also been reported in the literature. However, the available knowledge on various CW technologies considering the intensified and reliable removal of pollutants is still limited. Hence, this paper aims to provide an overview of the current development of CW strategies and techniques for enhanced wastewater treatment. Basic information on configurations and characteristics of different innovations was summarized. Then, overall treatment performance of those systems and their shortcomings were further discussed. Lastly, future perspectives were also identified for specialists to design more effective and sustainable CWs. This information is used to inspire some novel intensifying methodologies, and benefit the successful applications of potential CW technologies.
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Affiliation(s)
- Haiming Wu
- College of Natural Resources and Environment, Northwest A & F University, Yangling, Shaanxi, 712100, People's Republic of China
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan, 250100, People's Republic of China
| | - Jinlin Fan
- National Engineering Laboratory of Coal-Fired Pollutants Emission Reduction, Shandong University, Jinan, 250061, People's Republic of China
| | - Jian Zhang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, Sydney, NSW, 2007, Australia
| | - Wenshan Guo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, Sydney, NSW, 2007, Australia
| | - Shuang Liang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan, 250100, People's Republic of China
| | - Zhen Hu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan, 250100, People's Republic of China
| | - Hai Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan, 250100, People's Republic of China
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
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28
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Li F, Lu L, Zheng X, Ngo HH, Liang S, Guo W, Zhang X. Enhanced nitrogen removal in constructed wetlands: effects of dissolved oxygen and step-feeding. BIORESOURCE TECHNOLOGY 2014; 169:395-402. [PMID: 25069093 DOI: 10.1016/j.biortech.2014.07.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 06/03/2023]
Abstract
Four horizontal subsurface flow constructed wetlands (HSFCWs), named HSFCW1 (three-stage, without step-feeding), HSFCW2 (three-stage, with step-feeding), HSFCW3 (five-stage, without step-feeding) and HSFCW4 (five-stage, with step-feeding) were designed to investigate the effects of dissolved oxygen (DO) and step-feeding on nitrogen removal. High removal of 90.9% COD, 99.1% ammonium nitrogen and 88.1% total nitrogen (TN) were obtained simultaneously in HSFCW4 compared with HSFCW1-3. The excellent TN removal of HSFCW4 was due to artificial aeration provided sufficient DO for nitrification and the favorable anoxic environment created for denitrification. Step-feeding was a crucial factor because it provided sufficient carbon source (high COD: nitrate ratio of 14.3) for the denitrification process. Microbial activities and microbial abundance in HSFCW4 was found to be influenced by DO distribution and step-feeding, and thus improve TN removal. These results suggest that artificial aeration combined with step-feeding could achieve high nitrogen removal in HSFCWs.
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Affiliation(s)
- Fengmin Li
- Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
| | - Lun Lu
- Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Xiang Zheng
- School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China
| | - Huu Hao Ngo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Shuang Liang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan 250100, China
| | - Wenshan Guo
- School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Xiuwen Zhang
- Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China
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29
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Ju X, Wu S, Zhang Y, Dong R. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system. WATER RESEARCH 2014; 59:37-45. [PMID: 24784452 DOI: 10.1016/j.watres.2014.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 02/19/2014] [Accepted: 04/04/2014] [Indexed: 06/03/2023]
Abstract
A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions.
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Affiliation(s)
- Xinxin Ju
- College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, PR China
| | - Shubiao Wu
- Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Yansheng Zhang
- College of Water Resources & Civil Engineering, China Agricultural University, Beijing 100083, PR China
| | - Renjie Dong
- Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, Beijing 100083, PR China
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30
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Chang Y, Wu S, Zhang T, Mazur R, Pang C, Dong R. Dynamics of nitrogen transformation depending on different operational strategies in laboratory-scale tidal flow constructed wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 487:49-56. [PMID: 24768911 DOI: 10.1016/j.scitotenv.2014.03.114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/21/2014] [Accepted: 03/23/2014] [Indexed: 06/03/2023]
Abstract
The influence of different flooded/drained (F/D) time ratios and different effluent flow rates on the dynamics of nitrogen transformations in three laboratory-scale tidal flow constructed wetland systems (TFCWs-A, B, and C) under varying NH4(+)-N and COD influent loadings was investigated in this study. Good organic matter removal performance up to 90% was achieved for all experimental TFCWs under inflow concentrations of 300 and 150 mg/L regardless of F/D and effluent flow rate. The ammonium removal efficiency of wetland with F/D=3h:3h (55%) was higher than that of the wetland with F/D=5h:1h (47%) under an ammonium inflow concentration of 60 mg/L, indicating the positive effect of longer drained and shorter flooded time on tidal-operated wetlands under nitrification. In addition, more uniform oxygen distribution and better nitrification capacity within the wetland might be achieved with a relatively slow effluent flow rate of 0.025 L/s. TFCWs were shown to be a robust and reliable option to achieve high TN removal of 70% due to its repeated cycle of "wet" and "dry" periods, particularly for the treatment of wastewater with high organic content. Moreover, F/D and effluent flow rates of tidal flow constructed wetlands exhibited no significant effect on phosphorus removal in this study. Other techniques, such as pretreatment or post treatment, require further investigation.
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Affiliation(s)
- Yongjiang Chang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, PR China
| | - Shubiao Wu
- Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, 100083 Beijing, PR China.
| | - Tao Zhang
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, PR China
| | - Robert Mazur
- Department of Hydraulic and Sanitary Engineering, Faculty of Land Reclamation and Environmental Engineering, Poznan University of Life Sciences, Poland
| | - Changle Pang
- Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, 100083 Beijing, PR China
| | - Renjie Dong
- Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, 100083 Beijing, PR China
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31
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Wu S, Kuschk P, Brix H, Vymazal J, Dong R. Development of constructed wetlands in performance intensifications for wastewater treatment: a nitrogen and organic matter targeted review. WATER RESEARCH 2014; 57:40-55. [PMID: 24704903 DOI: 10.1016/j.watres.2014.03.020] [Citation(s) in RCA: 238] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/19/2014] [Accepted: 03/09/2014] [Indexed: 05/03/2023]
Abstract
The knowledge on the performance enhancement of nitrogen and organic matter in the expanded constructed wetlands (CWs) with various new designs, configurations, and technology combinations are still not sufficiently summarized. A comprehensive review is accordingly necessary for better understanding of this state-of-the-art-technology for optimum design and new ideas. Considering that the prevailing redox conditions in CWs have a strong effect on removal mechanisms and highly depend on wetland designs and operations, this paper reviews different operation strategies (recirculation, aeration, tidal operation, flow direction reciprocation, and earthworm integration), innovative designs, and configurations (circular-flow corridor wetlands, towery hybrid CWs, baffled subsurface CWs) for the intensifications of the performance. Some new combinations of CWs with technologies in other field for wastewater treatment, such as microbial fuel cell, are also discussed. To improve biofilm development, the selection and utilization of some specific substrates are summarized. Finally, we review the advances in electron donor supply to enhance low C/N wastewater treatment and in thermal insulation against low temperature to maintain CWs running in the cold areas. This paper aims to provide and inspire some new ideas in the development of intensified CWs mainly for the removal of nitrogen and organic matter. The stability and sustainability of these technologies should be further qualified.
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Affiliation(s)
- Shubiao Wu
- College of Engineering, China Agricultural University, Qinghua Donglu 17, Haidian District, 100083 Beijing, PR China.
| | - Peter Kuschk
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig D-04318, Germany
| | - Hans Brix
- Department of Bioscience, Aarhus University, Ole Worms Allé 1, 8000 Aarhus C., Denmark
| | - Jan Vymazal
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kymýcká 129, 165 21 Praha 6, Czech Republic
| | - Renjie Dong
- College of Engineering, China Agricultural University, Qinghua Donglu 17, Haidian District, 100083 Beijing, PR China
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32
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Hu Y, Zhao Y, Rymszewicz A. Robust biological nitrogen removal by creating multiple tides in a single bed tidal flow constructed wetland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 470-471:1197-204. [PMID: 24246943 DOI: 10.1016/j.scitotenv.2013.10.100] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/24/2013] [Accepted: 10/27/2013] [Indexed: 05/03/2023]
Abstract
Achieving effective total nitrogen (TN) removal is one of the major challenges faced by constructed wetlands (CWs). To address this issue, multiple "tides" were proposed in a single stage tidal flow constructed wetland (TFCW). With this adoption, exceptional TN removal (85% on average) was achieved under a high nitrogen loading rate (NLR) of around 28 g Nm(-2)day(-1), which makes the proposed system an adequate option to provide advanced wastewater treatment for peri-urban communities and rural area. It was revealed that the multiple "tides" not only promoted TN removal performance, but also brought more flexibility to TFCWs. Adsorption of NH4(+)-N onto the wetland medium (during contact period) and regeneration of the adsorption capacity via nitrification (during bed resting) were validated as the key processes for NH4(+)-N conversion in TFCWs. Moreover, simultaneous nitrification denitrification (SND) was found to be significant during the bed resting period. These findings will provide a new foundation for the design and modeling of nitrogen conversion and oxygen transfer in TFCWs.
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Affiliation(s)
- Yuansheng Hu
- UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland; Key Laboratory of Urban Stormwater System and Water Environment/R&D Centre for Sustainable Wastewater Treatment (Beijing University of Civil Engineering and Architecture), Ministry of Education, Beijing 100044, China.
| | - Yaqian Zhao
- UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland
| | - Anna Rymszewicz
- UCD Dooge Centre for Water Resources Research, School of Civil, Structural and Environmental Engineering, Newstead Building, University College Dublin, Belfield, Dublin 4, Ireland
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