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Zhou J, Zhu Y, Wen K, Pan F, Ma H, Niu J, Wang C, Zhao J. Efficient and Selective Electrochemical Nitrate Reduction to N 2 Using a Flow-Through Zero-Gap Electrochemical Reactor with a Reconstructed Cu(OH) 2 Cathode: Insights into the Importance of Inter-Electrode Distance. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4824-4836. [PMID: 38408018 DOI: 10.1021/acs.est.3c10936] [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: 02/28/2024]
Abstract
Electrochemically converting nitrate, a widely distributed nitrogen contaminant, into harmless N2 is a feasible and environmentally friendly route to close the anthropogenic nitrogen-based cycle. However, it is currently hindered by sluggish kinetics and low N2 selectivity, as well as scarce attention to reactor configuration. Here, we report a flow-through zero-gap electrochemical reactor that shows a high performance of nitrate reduction with 100% conversion and 80.36% selectivity of desired N2 in the chlorine-free system at 100 mg-N·L-1 NO3- while maintaining a rapid reduction kinetics of 0.07676 min-1. More importantly, the mass transport and current utilization efficiency are significantly improved by shortening the inter-electrode distance, especially in the zero-gap electrocatalytic system where the current efficiency reached 50.15% at 5 mA·cm-2. Detailed characterizations demonstrated that during the electroreduction process, partial Cu(OH)2 on the cathode surface was reconstructed into stable Cu/Cu2O as the active phase for efficient nitrate reduction. In situ characterizations revealed that the highly selective *NO to *N conversion and the N-N coupling step played crucial roles during the selective reduction of NO3- to N2 in the zero-gap electrochemical system. In addition, theoretical calculations demonstrated that improving the key intermediate *N coverage could effectively facilitate the N-N coupling step, thereby promoting N2 selectivity. Moreover, the environmental and economic benefits and long-term stability shown by the treatment of real nitrate-containing wastewater make our proposed electrocatalytic system more attractive for practical applications.
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Affiliation(s)
- Jianjun Zhou
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xian 710021, China
- College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023, China
| | - Yunqing Zhu
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xian 710021, China
| | - Kaiyue Wen
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xian 710021, China
| | - Fan Pan
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xian 710021, China
| | - Hongrui Ma
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xian 710021, China
| | - Junfeng Niu
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Chuanyi Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xian 710021, China
| | - Jincai Zhao
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Gül E, Kayaalp N. Modelling of hydrogenotrophic denitrification process in a venturi-integrated membrane bioreactor. ENVIRONMENTAL TECHNOLOGY 2024; 45:945-958. [PMID: 36173672 DOI: 10.1080/09593330.2022.2130827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
The aim of this study is to model a hydrogenotrophic denitrification process in a venturi-integrated submerged membrane bioreactor (MBR) system. The MBR was operated in batch mode using feed concentrations of 100 and 150 mg NO3-N/L. In contrast to most of the denitrification process models that represent the mixed culture with one composite biomass parameter, the biomass was subdivided into two main categories in this modelling study: mainly nitrate-reducing biomass and mainly nitrite-reducing biomass. The determination coefficients (r2) in the range of 0.97-0.99 indicate that the model successfully simulates the concentrations of nitrate- and nitrite-nitrogen in the bioreactor. The maximum specific growth rate of nitrite-reducing biomass (0.06 h-1) was found to be higher than that of nitrate-reducing biomass (0.0002 h-1). Similarly, the growth yield coefficient of nitrite-reducing biomass was higher than that of nitrate-reducing biomass (0.44 vs. 0.31 g biomass/g substrate). The kinetic and stoichiometric coefficients obtained from this modelling study suggest that the limiting step determining the overall conversion rate of hydrogenotrophic denitrification process is the conversion of nitrite to nitrogen gas.
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Affiliation(s)
- Ertuğrul Gül
- Environmental Health Department, Hakkari University, Hakkari, Turkey
| | - Necati Kayaalp
- Civil Engineering Department, Dicle University, Diyarbakir, Turkey
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Shen Z, Fang M, Tang L, Shi J, Wang W. Pd/Cu bimetallic nano-catalyst supported on anion exchange resin (A520E) for nitrate removal from water: High property and stability. ENVIRONMENTAL RESEARCH 2024; 241:117616. [PMID: 37956750 DOI: 10.1016/j.envres.2023.117616] [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: 08/05/2023] [Revised: 10/26/2023] [Accepted: 11/06/2023] [Indexed: 11/15/2023]
Abstract
High nitrate concentration in water can lead to eutrophication and the disruption of healthy aquatic ecosystems. Additionally, in the human digestive system, it has the potential to be reduced to nitrite, which can be damaging to people's physical health. Catalytic hydrogenation of nitrate is one of the strategies for removing nitrate from water. Using A520E resin as support, we prepared Pd/Cu nano-catalyst (Pd/Cu@A520E) according to a liquid phase reduction method. A520E could improve the transfer process of nitrate in the solution to the activity sites of Pd/Cu nanoparticles, thus increase the reaction rate of nitrate reduction. Pd/Cu bimetallic nano-particles were evenly distributed on/in the resin with a size range from 2 nm to 10 nm. The External Circulating System equipped with Venturi tube (ECSV) was designed to improve the utilization efficiency of H2 in both batch tests and long-term continuous-flow tests. Nearly 100% of nitrate removal efficiency and above 90% of N2 selectivity were achieved in both batch tests and continuous-flow tests. Coexisting Cl- and SO42- at 300 mg/L showed little impact on the property of Pd/Cu@A520E. Pd/Cu@A520E also showed high nitrate removal property and stability in continuous-flow tests of more than 800 h. NO3- was adsorbed onto the active sites (functional groups and Pd/Cu particle sites), meanwhile H2 was adsorbed onto the active sites of Pd/Cu@A520E to form Pd [H]. Then the adsorbed NO3- was reduced into N2 (main product) or NH4+ by Pd [H]. In addition, Pd/Cu@A520E showed high nitrate removal property from municipal waste water.
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Affiliation(s)
- Zhanhui Shen
- Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, School of Environment, Henan Normal University, Xinxiang, 453007, China; Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, School of Geographic Sciences, Xinyang Normal University, Xinyang, 464000, China.
| | - Menghao Fang
- Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, School of Environment, Henan Normal University, Xinxiang, 453007, China
| | - Li Tang
- Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, School of Environment, Henan Normal University, Xinxiang, 453007, China
| | - Jialu Shi
- Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, School of Environment, Henan Normal University, Xinxiang, 453007, China; Henan Key Laboratory for Synergistic Prevention of Water and Soil Environmental Pollution, School of Geographic Sciences, Xinyang Normal University, Xinyang, 464000, China
| | - Wanfeng Wang
- Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, School of Environment, Henan Normal University, Xinxiang, 453007, China.
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Pan Z, Li Z, Zeng B, Shen L, Lin H. Enhanced denitrification performance of granular sludge for the treatment of waste brine from ion exchange resin process. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118473. [PMID: 37413732 DOI: 10.1016/j.jenvman.2023.118473] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 07/08/2023]
Abstract
Ion exchange resin process is a widely used process in wastewater treatment plants, but its waste brine is characterized by high salinity and nitrate concentration, leading to costly treatment. This study innovatively explored the use of an up-flow anaerobic sludge bed (USB) for the treatment of waste brine from ion exchange resin process, following a pilot-scale ion exchange resin process. Specifically, the D890 ion exchange resin was employed for nitrate removal from secondary effluent, with resin regeneration using 4% NaCl solution. The USB was inoculated with anaerobic granular sludge and acclimated under various single-factor conditions, which revealed the optimal pH range of 6.5-9, salt concentration of 2%, hydraulic retention time of 12 h, C/N ratio of 3.3, and up-flow velocity of 1.5 m/h for reactor operation. This study provides a novel approach for the cost-effective treatment of waste brine from ion exchange resin process. The study found that the denitrification efficiency was highest when the NO3--N concentration was around 200 mg/L, with NO3--N and TN removal rates exceeding 95% and 90%, respectively, under optimal operating conditions. Characterization of the granular sludge during different phases of the operation revealed a significant increase in proteobacteria and gradually became the dominant species over time. This study presents a novel, cost-effective approach to treat waste brine from ion exchange resin process, and the long-term stable operation of the reactor offers a reliable option for resin regeneration wastewater treatment.
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Affiliation(s)
- Zhenxiang Pan
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Zhongqiang Li
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China.
| | - Bizhen Zeng
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Liguo Shen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
| | - Hongjun Lin
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Watershed Earth Surface Processes and Ecological Security, Zhejiang Normal University, Jinhua, 321004, China.
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Wu M, Lai CY, Wang Y, Yuan Z, Guo J. Microbial nitrate reduction in propane- or butane-based membrane biofilm reactors under oxygen-limiting conditions. WATER RESEARCH 2023; 235:119887. [PMID: 36947926 DOI: 10.1016/j.watres.2023.119887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 03/02/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Nitrate contamination has been commonly detected in water environments and poses serious hazards to human health. Previously methane was proposed as a promising electron donor to remove nitrate from contaminated water. Compared with pure methane, natural gas, which not only contains methane but also other short chain gaseous alkanes (SCGAs), is less expensive and more widely available, representing a more attractive electron source for removing oxidized contaminants. However, it remains unknown if these SCGAs can be utilized as electron donors for nitrate reduction. Here, two lab-scale membrane biofilm reactors (MBfRs) separately supplied with propane and butane were operated under oxygen-limiting conditions to test its feasibility of microbial nitrate reduction. Long-term performance suggested nitrate could be continuously removed at a rate of ∼40-50 mg N/L/d using propane/butane as electron donors. In the absence of propane/butane, nitrate removal rates significantly decreased both in the long-term operation (∼2-10 and ∼4-9 mg N/L/d for propane- and butane-based MBfRs, respectively) and batch tests, indicating nitrate bio-reduction was driven by propane/butane. The consumption rates of nitrate and propane/butane dramatically decreased under anaerobic conditions, but recovered after resupplying limited oxygen, suggesting oxygen was an essential triggering factor for propane/butane-based nitrate reduction. High-throughput sequencing targeting 16S rRNA, bmoX and narG genes indicated Mycobacterium/Rhodococcus/Thauera were the potential microorganisms oxidizing propane/butane, while various denitrifiers (e.g. Dechloromonas, Denitratisoma, Zoogloea, Acidovorax, Variovorax, Pseudogulbenkiania and Rhodanobacter) might perform nitrate reduction in the biofilms. Our findings provide evidence to link SCGA oxidation with nitrate reduction under oxygen-limiting conditions and may ultimately facilitate the design of cost-effective techniques for ex-situ groundwater remediation using natural gas.
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Affiliation(s)
- Mengxiong Wu
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Queensland, Australia
| | - Chun-Yu Lai
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Queensland, Australia
| | - Yulu Wang
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Queensland, Australia
| | - Zhiguo Yuan
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Queensland, Australia
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology, Faculty of Engineering, Architecture and Information Technology, The University of Queensland, St Lucia, Queensland, Australia.
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Synthesis, Adsorption Isotherm and Kinetic Study of Alkaline- Treated Zeolite/Chitosan/Fe 3+ Composites for Nitrate Removal from Aqueous Solution-Anion and Dye Effects. Gels 2022; 8:gels8120782. [PMID: 36547306 PMCID: PMC9777915 DOI: 10.3390/gels8120782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/25/2022] [Accepted: 11/26/2022] [Indexed: 12/02/2022] Open
Abstract
In the present study, alkaline-treated zeolite/chitosan/Fe3+ (ZLCH-Fe) composites were prepared and analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and pH of zero point of charge (pHzpc) to remove nitrates from water. The process was carried out using an adsorption method with a varied initial pH, adsorbent dosage, initial nitrate concentration and contact time. The pHzpc demonstrated that the ZLCH-Fe surface had a positive charge between 2 and 10, making it easier to capture the negative charge of nitrate. However, the optimal pH value is 7. After 270 min, the maximum adsorption capacity and percent removal reached 498 mg/g and 99.64%, respectively. Freundlich and pseudo-second-order were fitted to the adsorption isotherm and kinetic models, respectively. An evaluation was conducted on the effects of anions-SO42- and PO43--and dyes-methylene blue (MB) and acid red 88 (AR88)-upon nitrate removal. The results indicated that the effect of the anion could be inhibited, in contrast to dye effects. However, the optimal pH values were changed to 10 for MB and 2 for AR88, resulting in a hydrogel formation. This might be indicated by the protonation of hydroxyl and amino groups resulting from a chitosan nitrate reaction in the AR88 solution.
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Silveira JE, Garcia-Costa AL, Carbajo J, Ribeiro AR, Pliego G, Paz WS, Zazo JA, Casas JA. Nitrate removal in saline water by photo-reduction using natural FeTiO3 as catalyst. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Zhou C, Li J, Zhang Y, Bai J, Li L, Mei X, Guan X, Zhou B. Novel Denitrification Fuel Cell for Energy Recovery of Nitrate-N and TN Removal Based on NH 4+ Generation on a CNW@CF Cathode. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:2562-2571. [PMID: 35112834 DOI: 10.1021/acs.est.1c04363] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
NO3- is an undesirable environmental pollutant that causes eutrophication in aquatic ecosystems, and its pollution is difficult to eliminate because it is easily converted into NH4+ instead of N2. Additionally, it is a high-energy substance. Herein, we propose a novel denitrification fuel cell to realize the chemical energy recovery of NO3- and simultaneous conversion of total nitrogen (TN) into N2 based on the outstanding ability of NH4+ generation on a three-dimensional copper nanowire (CNW)-modified copper foam (CF) cathode (CNW@CF). The basic steps are as follows: direct and highly selective reduction of NO3- to NH4+ rather than to N2 on the CNW@CF cathode, on which negative NO3- ions can be easily adsorbed due to their double-electron layer structure and active hydrogen ([H]) can be generated due to a large number of catalytic active sites exposed on CNWs. Then, NH4+ is selectively oxidized to N2 by the strong oxidation of chlorine free radicals (Cl•), which originate from the reaction of chlorine ions (Cl-) by photogenerated holes (h+) and hydroxyl radicals (OH•) under irradiation. Then, the electrons from the oxidation on the photoanode is transferred to the cathode to form a closed loop for external power generation. Owing to the continuous redox loop, NO3- completely reduces to N2, and the released chemical energy is converted into electrical energy. The results indicate that 99.9% of NO3- can be removed in 90 min, and the highest yield of electrical power density reaches 0.973 mW cm-2, of which the nitrate reduction rates on the CNW@CF cathode is 79 and 71 times higher than those on the Pt and CF cathodes, respectively. This study presents a novel and robust energy recycling concept for treating nitrate-rich wastewater.
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Affiliation(s)
- Changhui Zhou
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jinhua Li
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Yan Zhang
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jing Bai
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China
| | - Lei Li
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Xiaojie Mei
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Xiaohong Guan
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China
| | - Baoxue Zhou
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, P. R. China
- Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming, Yunnan 650034, P. R. China
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Liu Z, Haddad M, Sauvé S, Barbeau B. Alleviating the burden of ion exchange brine in water treatment: From operational strategies to brine management. WATER RESEARCH 2021; 205:117728. [PMID: 34619606 DOI: 10.1016/j.watres.2021.117728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/21/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Ion exchange (IX) using synthetic resins is a cost-efficient technology to cope with a wide range of contaminants in water treatment. However, implementing IX processes is constrained by the regeneration of IX resins that generates a highly concentrated brine (i.e., IX brine), the disposal of which is costly and detrimental to ecosystems. In an effort to make the application of IX resins more sustainable in water treatment, substantial research has been conducted on the optimization of IX resins operation and the management of IX brine. The present review critically evaluates the literature surrounding IX operational strategies and IX brine management which can be used to limit the negative impacts arising from IX brine. To this end, we first analyzed the physicochemical characteristics of brines from the regeneration of IX resins. Then, we critically evaluated IX operational strategies that facilitate brine management, including resin selection, contactor selection, operational modes, and regeneration strategies. Furthermore, we analyzed IX brine management strategies, including brine reuse and brine disposal (without or with treatment). Finally, a novel workflow for the IX water treatment plant design that integrates IX operational strategies and IX brine management is proposed, thereby highlighting the areas that make IX technology more sustainable for water treatment.
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Affiliation(s)
- Zhen Liu
- Department of Chemistry, Université de Montréal, Montréal, QC H2V 0B3, Canada; NSERC-Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada.
| | - Maryam Haddad
- Department of Chemical Engineering, California State University, Long Beach, CA 90840, United States.
| | - Sébastien Sauvé
- Department of Chemistry, Université de Montréal, Montréal, QC H2V 0B3, Canada.
| | - Benoit Barbeau
- NSERC-Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada.
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Chen M, Bi J, Huang X, Wang T, Wang Z, Hao H. Bi 2O 3 nanosheets arrays in-situ decorated on carbon cloth for efficient electrochemical reduction of nitrate. CHEMOSPHERE 2021; 278:130386. [PMID: 33823352 DOI: 10.1016/j.chemosphere.2021.130386] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/21/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Excessive nitrate in industrial wastewater is still an important environmental protection issue for human beings. As nitrate promoter metal, Sn has been extensively studied in nitrate reduction reaction (NITRR). However, it suffers from high selectivity of nitrite as the final product at times. As the same main group as Sn, bismuth-based materials have exhibited excellent performance in the field of electrochemical reduction reactions but were rarely investigated for NITRR. In this study, Bi2O3 nanosheets in-situ decorated on carbon cloth (Bi2O3-CC) was synthesized and it showed larger surface area and higher electrical conductivity than those of dropped Bi2O3 nanosheets onto carbon cloth (Bi2O3/CC). Experimental results show that the nitrate removal efficiency of Bi2O3-CC increased by 12.7% than that of Bi2O3/CC at the same condition. Besides, the presence of Cl- benefits the NITRR process since the reaction of Bi2O3 and Cl- in acidic conditions can accelerate the conversion of Bi3+ to Bi0. The mechanism of the NITRR process was proposed based on the electrochemical and scavenging experiments. It was found that both the direct electron transfer and atomic H∗ contribute to the electrochemical reduction of nitrate to ammonia. More importantly, when Bi2O3-CC was applied to actual garbage fly ash wastewater, most nitrates were converted to ammonia. The designed Bi2O3-CC is a high-potential material for converting nitrate in industrial wastewater to valuable feedstock chemical ammonia with high efficiency.
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Affiliation(s)
- Miao Chen
- National Engineering Research Center for Industry Crystallization Technology,School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Jingtao Bi
- National Engineering Research Center for Industry Crystallization Technology,School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Xin Huang
- National Engineering Research Center for Industry Crystallization Technology,School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China; Co-Innovation Center of Chemical Science and Engineering, Tianjin, 300072, China.
| | - Ting Wang
- National Engineering Research Center for Industry Crystallization Technology,School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Zhao Wang
- National Engineering Research Center for Industry Crystallization Technology,School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Hongxun Hao
- National Engineering Research Center for Industry Crystallization Technology,School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China; Co-Innovation Center of Chemical Science and Engineering, Tianjin, 300072, China; School of Chemical Engineering and Technology, Hainan University, Haikou, 570228, China.
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11
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Mosleh I, Abbaspourrad A. Peptide-directed Pd-decorated Au and PdAu nanocatalysts for degradation of nitrite in water. RSC Adv 2021; 11:32615-32621. [PMID: 35493599 PMCID: PMC9042164 DOI: 10.1039/d1ra05304c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/29/2021] [Indexed: 01/18/2023] Open
Abstract
In this work, a palladium binding peptide, Pd4, has been used for the synthesis of catalytically active palladium-decorated gold (Pd-on-Au) nanoparticles (NPs) and palladium–gold (PdxAu100−x) alloy NPs exhibiting high nitrite degradation efficiency. Pd-on-Au NPs with 20% to 300% surface coverage (sc%) of Au showed catalytic activity commensurate with sc%. Additionally, the catalytic activity of PdxAu100−x alloy NPs varied based on palladium composition (x = 6–59). The maximum nitrite removal efficiency of Pd-on-Au and PdxAu100−x alloy NPs was obtained at sc 100% and x = 59, respectively. The synthesized peptide-directed Pd-on-Au catalysts showed an increase in nitrite reduction three and a half times better than monometallic Pd and two and a half times better than PdxAu100−x NPs under comparable conditions. Furthermore, peptide-directed NPs showed high activity after five reuse cycles. Pd-on-Au NPs with more available activated palladium atoms showed high selectivity (98%) toward nitrogen gas production over ammonia. In this work, a palladium binding peptide, Pd4, has been used for the synthesis of catalytically active palladium-decorated gold (Pd-on-Au) nanoparticles (NPs) and palladium–gold (PdxAu100−x) alloy NPs exhibiting high nitrite degradation efficiency.![]()
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Affiliation(s)
- Imann Mosleh
- Department of Food Science, College of Agricultural and Life Sciences, Cornell University, Stocking Hall, Ithaca, NY, 14853, USA
| | - Alireza Abbaspourrad
- Department of Food Science, College of Agricultural and Life Sciences, Cornell University, Stocking Hall, Ithaca, NY, 14853, USA
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12
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Quality and Health Risk Assessment Associated with Water Consumption—A Case Study on Karstic Springs. WATER 2020. [DOI: 10.3390/w12123510] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In rural areas without centralized water supply systems, inhabitants often use groundwater of unknown quality as drinking water, without understanding the possible negative consequences on their health. Karstic spring waters from Dobrogea region in Romania were assessed for their potential to be used as drinking water source, according to their quality and seasonal variation. The physico-chemical parameters of waters were compared with the guideline values for drinking water established by the World Health Organization and the Directive 98/83/EC. The nitrate and Cr concentrations exceeded the guideline value in the springs from Southern Dobrogea, but met the quality criteria in those from Northern Dobrogea, thus, to be used as drinking water, the karstic springs located in Southern Dobrogea require treatment for nitrates removal. Heavy metals pollution indices showed low to medium cumulative heavy metal pollution in all springs, while the human health risk assessment by oral exposure indicated possible noncarcinogenic risks of nitrates, both for adults and children in springs from South Dobrogea. A rigorous monitoring of the water quality before human consumption is recommended for all four studied water sources.
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Guo XF, Li D, Liu JL, Wang ZR, Wang J, Zhao YY, Yuan JS. Separation of sodium and potassium using adsorption – elution/crystallization scheme from bittern. Chem Eng Res Des 2020. [DOI: 10.1016/j.cherd.2020.06.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Su JF, Li GQ, Huang TL, Xue L. The mixotrophic denitrification characteristics of Zoogloea sp. L2 accelerated by the redox mediator of 2-hydroxy-1,4-naphthoquinone. BIORESOURCE TECHNOLOGY 2020; 311:123533. [PMID: 32460131 DOI: 10.1016/j.biortech.2020.123533] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Denitrification in mixed culture system has been extensively researched to date, but few studies have focused on accelerating the process using redox mediators to promote electron transfer. Strain L2, an iron-reducing bacteria, can remove 75.44% of nitrate under temperature of 30.60 °C, pH of 6.75 and Fe2+ concentration of 27.86 mg·L-1. Additionally, the removal rate of nitrate reached 1.516 mg·L-1·h-1 in 8 h with the addition of 0.030 mmol·L-1 2-hydroxy-1,4-naphthoquinone (HNQ), which increased by 1.38 times than control group. Furthermore, analysis by fluorescence spectroscopy, flow cytometer and gas chromatography demonstrated that HNQ positively stimulated denitrification. This study provides a reference for enhancing denitrification in mixed culture and lays the foundation for the practical application of redox mediators in groundwater treatment.
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Affiliation(s)
- Jun Feng Su
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Guo Qing Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Ting Lin Huang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Lei Xue
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
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Sulphate Removal from Flotation Process Water Using Ion-Exchange Resin Column System. MINERALS 2020. [DOI: 10.3390/min10080655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Water chemistry is one of the most important parameters affecting flotation performance. Various types of ions can dissolve and accumulate in process water depending on ore mineralogy, reagent scheme, grinding medium and chemistry of mine site water. Sulfur-based ions (sulfate, thiosulfate, polythionate) are generally observed in flotation of sulfide ores. High concentrations of these ions may reduce efficiency of the flotation process, causing scale problems. Removal of these ions from process water often requires complex water treatment plants with high capital and operating costs. In this study, partial cleaning of water was investigated as an alternative approach for decreasing high sulphate concentrations of 3000–3800 mg/L down to 1000–1500 mg/L, an acceptable concentration for most sulfide ore flotation plants, by using an ion-exchange resin. For this purpose, detailed adsorption tests were performed using a laboratory-scale column system to determine the most suitable type of resin for adsorption of sulfate and thiosalts, kinetics of adsorption and regeneration of the resins. A strong base anion ion exchange resin (Selion SBA2000) was used in the experiments. The findings from the laboratory scale studies were validated in a Cu-Pb-Zn Flotation Plant in an Iberian mine using a larger scale of column set-up. The results showed that 60–70% of sulphates could be successfully removed from process water. Adsorption capacity of the resin was determined as 80.3 mg SO4/g resin. Concentrations of thiosalts and polythionates were also reduced to nearly zero value from 500 mg/L and 1000 mg/L, respectively. Flowrate of water had a significant effect on adsorption performance. The resin could be regenerated successfully using 2% (w/v) NaOH solution and used multiple times for water treatment.
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