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Wei J, Li Y, Lin H, Lu X, Zhou C, Li YY. Copper-based electro-catalytic nitrate reduction to ammonia from water: Mechanism, preparation, and research directions. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 20:100383. [PMID: 38304117 PMCID: PMC10830547 DOI: 10.1016/j.ese.2023.100383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 02/03/2024]
Abstract
Global water bodies are increasingly imperiled by nitrate pollution, primarily originating from industrial waste, agricultural runoffs, and urban sewage. This escalating environmental crisis challenges traditional water treatment paradigms and necessitates innovative solutions. Electro-catalysis, especially utilizing copper-based catalysts, known for their efficiency, cost-effectiveness, and eco-friendliness, offer a promising avenue for the electro-catalytic reduction of nitrate to ammonia. In this review, we systematically consolidate current research on diverse copper-based catalysts, including pure Cu, Cu alloys, oxides, single-atom entities, and composites. Furthermore, we assess their catalytic performance, operational mechanisms, and future research directions to find effective, long-term solutions to water purification and ammonia synthesis. Electro-catalysis technology shows the potential in mitigating nitrate pollution and has strategic importance in sustainable environmental management. As to the application, challenges regarding complexity of the real water, the scale-up of the commerical catalysts, and the efficient collection of produced NH3 are still exist. Following reseraches of catalyst specially on long term stability and in situ mechanisms are proposed.
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Affiliation(s)
| | | | | | | | - Chucheng Zhou
- Shenzhen Key Laboratory of Special Functional Materials & Shenzhen Engineering Laboratory for Advance Technology of Ceramics, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, PR China
| | - Ya-yun Li
- Shenzhen Key Laboratory of Special Functional Materials & Shenzhen Engineering Laboratory for Advance Technology of Ceramics, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, PR China
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2
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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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3
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Zhang Q, Chen XQ, Lan XY, Hong JM. Modulating Cu valence state in Cu and graphene oxide composites for electrocatalytic tetracycline hydrochloride degradation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:112252-112266. [PMID: 37831265 DOI: 10.1007/s11356-023-30269-2] [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: 04/17/2023] [Accepted: 10/01/2023] [Indexed: 10/14/2023]
Abstract
Cu and graphene oxide composites (Cu-GO) were designed by anchoring Cu+ via oxygen groups in GO based on the heavy co-relationships of copper (Cu) anode electrocatalytic activity with Cu valence state. With the consumption of oxygen groups under various pyrolysis temperatures, the Cu valence state changed from Cu ions (as CuCl2 and CuCl) to Cu oxide (CuO and Cu2O) and the final metallic Cu. In which the Cu+ in CuCl was more favorable for electrocatalytic oxidation than other Cu valence states. Due to the dramatic contribution of 1O2 and active chlorine, 100% degradation efficiency was achieved using tetracycline hydrochloride (TCH) as the target pollutant. Cu+ showed a selective preference for 1O2 and active chlorine triggering, rather than metallic Cu. Under the attack of 1O2 and active chlorine, the degradation intermediates of TCH were then provided by LC-MS results. The final results not only prove the feasibility of the Cu-GO/electrocatalysis system for pollution control but also shed light on the anode design via Cu valence state modulation.
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Affiliation(s)
- Qian Zhang
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
- Xiamen Engineering Research Center of Industrial Wastewater Biochemical Treatment, Xiamen, 361021, China
- Fujian Provincial Research Center of Industrial Wastewater Biochemical Treatment, Huaqiao University, Xiamen, 361021, China
| | - Xiao-Qi Chen
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
- Xiamen Engineering Research Center of Industrial Wastewater Biochemical Treatment, Xiamen, 361021, China
- Fujian Provincial Research Center of Industrial Wastewater Biochemical Treatment, Huaqiao University, Xiamen, 361021, China
| | - Xin-Yue Lan
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
- Xiamen Engineering Research Center of Industrial Wastewater Biochemical Treatment, Xiamen, 361021, China
- Fujian Provincial Research Center of Industrial Wastewater Biochemical Treatment, Huaqiao University, Xiamen, 361021, China
| | - Jun-Ming Hong
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China.
- Xiamen Engineering Research Center of Industrial Wastewater Biochemical Treatment, Xiamen, 361021, China.
- Fujian Provincial Research Center of Industrial Wastewater Biochemical Treatment, Huaqiao University, Xiamen, 361021, China.
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4
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Coupling nitrate capture with ammonia production through bifunctional redox-electrodes. Nat Commun 2023; 14:823. [PMID: 36788213 PMCID: PMC9929237 DOI: 10.1038/s41467-023-36318-1] [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: 09/14/2022] [Accepted: 01/24/2023] [Indexed: 02/16/2023] Open
Abstract
Nitrate is a ubiquitous aqueous pollutant from agricultural and industrial activities. At the same time, conversion of nitrate to ammonia provides an attractive solution for the coupled environmental and energy challenge underlying the nitrogen cycle, by valorizing a pollutant to a carbon-free energy carrier and essential chemical feedstock. Mass transport limitations are a key obstacle to the efficient conversion of nitrate to ammonia from water streams, due to the dilute concentration of nitrate. Here, we develop bifunctional electrodes that couple a nitrate-selective redox-electrosorbent (polyaniline) with an electrocatalyst (cobalt oxide) for nitrate to ammonium conversion. We demonstrate the synergistic reactive separation of nitrate through solely electrochemical control. Electrochemically-reversible nitrate uptake greater than 70 mg/g can be achieved, with electronic structure calculations and spectroscopic measurements providing insight into the underlying role of hydrogen bonding for nitrate selectivity. Using agricultural tile drainage water containing dilute nitrate (0.27 mM), we demonstrate that the bifunctional electrode can achieve a 8-fold up-concentration of nitrate, a 24-fold enhancement of ammonium production rate (108.1 ug h-1 cm-2), and a >10-fold enhancement in energy efficiency when compared to direct electrocatalysis in the dilute stream. Our study provides a generalized strategy for a fully electrified reaction-separation pathway for modular nitrate remediation and ammonia production.
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Ashoori R, Samaei MR, Yousefinejad S, Azhdarpoor A, Emadi Z, Mohammadpour A, Lari AR, Mousavi Khaneghah A. Simultaneous removal of fluoride and nitrate from synthetic aqueous solution and groundwater by the electrochemical process using non-coated and coated anode electrodes: A human health risk study. ENVIRONMENTAL RESEARCH 2022; 214:113938. [PMID: 35977584 DOI: 10.1016/j.envres.2022.113938] [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: 03/21/2022] [Revised: 07/10/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Co-presence of fluoride (F-) and nitrate (NO3-) in water causes numerous health complications. Thus, they should be eliminated by an appropriate method like the EC process. In this research, simultaneous removal of F- and NO3- from synthetic aqueous solution and groundwater has been considered by the EC technique under operational parameters like anode materials (un-coated (Al and Fe) and synthesized coated (Ti/TiRuSnO2 and Ti/PbO2)), cathode materials (Cu, St, and Gr), current density (12, 24, and 36 mA/cm2), inter-electrode distance (0.5, 1, and 2 cm), pH (5.5, 7, and 8.5), NaCl concentrations (0.5, 1, and 1.5 g/L), electrolysis time (15, 30, 45, 60, 90, and 120 min), NO3- concentrations (75, 150, and 225 mg/L), and F- concentrations (2, 4, 6, and 8 mg/L) for the first time in this research. The results proved that Al as non-coated anode and Cu as cathode electrodes were more effective in the co-removal of F- and NO3-. The maximum removal efficiencies of 94.19 and 95% were observed at the current density of 36 mA/cm2, 1 cm of inter-electrode distance, pH 7, 1 g/L of NaCl, and 90 min electrolysis time by Al-Cu electrode for F- (2 mg/L) and NO3- (75 mg/L), respectively. The higher efficiency of Al-Cu electrodes was due to the simultaneous occurrence of electrocoagulation, electroreduction, and electrooxidation processes. Al-Cu electrode application considerably diminished f- and NO3- concentrations in the groundwater. Health risk assessment proved that HQ of F- was significantly decreased after treatment by the Al-Cu electrode. Thus, the EC process using an appropriate and effective electrode is a promising technique for treating aqueous solutions containing F- and NO3-.
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Affiliation(s)
- Razieh Ashoori
- Department of Environmental Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Reza Samaei
- Department of Environmental Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Saeed Yousefinejad
- Research Center for Health Sciences, Institute of Health, Department of Occupational Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abooalfazl Azhdarpoor
- Department of Environmental Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Emadi
- Department of Environmental Health Engineering, School of Health, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Amin Mohammadpour
- Department of Chemical Engineering, School of Chemical and Petroleum Engineering, Shiraz University, 71946-84636 Shiraz, Iran
| | - Ali Rasti Lari
- School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia
| | - Amin Mousavi Khaneghah
- Department of Fruit and Vegetable Product Technology, Prof. Wacław Dąbrowski Institute of Agricultural and Food Biotechnology - State Research Institute, 36 Rakowiecka St., 02-532, Warsaw, Poland.
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6
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Hong M, Wang Q, Sun J, Wu C. A highly active copper-nanoparticle-based nitrate reduction electrocatalyst prepared by in situ electrodeposition and annealing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154349. [PMID: 35257778 DOI: 10.1016/j.scitotenv.2022.154349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/18/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
In recent years, copper-based electrodes have attracted intense attention for the electrochemical reduction of nitrate (NO3-), the so-called ECRN. However, these electrodes suffer from low activity and selectivity. Herein, we report a novel Cu-based electrode (IE-Cu-400) for the ECRN fabricated by loading Cu-based nanoparticles onto graphite felt using in situ electrodeposition followed by annealing. Compared with traditional Cu-based electrodes, the IE-Cu-400 is comprised of smaller particles and the copper is present in a high oxidation state (Cu2+ in CuO). During operation, the CuO is converted to Cu, which is the active ECRN species. In addition, an increased surface area and high density of grain boundaries resulting from the reduction of CuO were observed for IE-Cu-400. This resulted in a 3.38-fold increase in the NO3- removal rate and a 1.36-fold increase in NH4+ selectivity. Further analyses revealed that the enhanced ECRN performance of IE-Cu-400 is linked to its increased number of active sites, as well as its improved adsorption and reduction ability for NO2-. Moreover, IE-Cu-400 displays high stability for the ECRN. Finally, the produced NH4+ was effectively oxidised to N2 with approximately 100% selectivity via chlorination. Hence, the two-stage treatment strategy (i.e. ECRN by IE-Cu-400 + chlorination treatment) presented here shows great potential for the complete electrocatalytic denitrification of water. Further, this work highlights the beneficial effect of decreasing the particle size and controlling the surface oxidation of Cu-based catalysts simultaneously for enhancing the ECRN and offers new suggestions for the design of high-performance electrode materials for the ECRN.
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Affiliation(s)
- Min Hong
- School of Resources and Environmental Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Qinian Wang
- School of Resources and Environmental Engineering, Anhui University, Hefei, Anhui 230601, China; Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Hefei, Anhui 230601, China.
| | - Jun Sun
- School of Resources and Environmental Engineering, Anhui University, Hefei, Anhui 230601, China
| | - Chao Wu
- School of Resources and Environmental Engineering, Anhui University, Hefei, Anhui 230601, China
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7
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Tan X, Wang X, Zhou T, Chen T, Liu Y, Ma C, Guo H, Li B. Preparation of three dimensional bimetallic Cu-Ni/NiF electrodes for efficient electrochemical removal of nitrate nitrogen. CHEMOSPHERE 2022; 295:133929. [PMID: 35149017 DOI: 10.1016/j.chemosphere.2022.133929] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
It still remains a hotspot and great challenge to efficiently remove the nitrate nitrogen from high salt wastewater. Herein, a novel three dimensional porous bimetallic copper-nickel alloy electrode was fabricated with Ni foam (NiF) as substrate. The physicochemical and electrochemical characterization results showed Cu-Ni/NiF electrode possessed the smaller particle size (0.3-1.0 μm) and electrode film resistance comparing with Ni/NiF and Cu/NiF electrodes. Besides, higher double layer capacitance (Cdl) for Cu-Ni/NiF electrode indicated more electrochemical active sites could be used in the electrochemical nitrate nitrogen (NO3--N) removal. The electrochemical experiments showed the Cu-Ni/NiF electrode had the optimal NO3--N reduction ability and almost 100% NO3--N removal could be achieved with 30 min. All NO3--N removal processes were in accord with the pseudo-first-order reaction kinetics completely. The gaseous nitrogen selectivity for Cu-Ni/NiF electrode could reach 80.9% within 300 min. Stability assessment experiments indicated the Cu-Ni/NiF electrode all kept an excellent stability with Na2SO4 or NaCl electrolyte and the Cl- addition could significantly improve the gaseous nitrogen selectivity. Finally, a possible removal mechanism of NO3--N was proposed. This work offered a direction for designing non-noble bimetallic electrodes for nitrate removal.
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Affiliation(s)
- Xiangdong Tan
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China.
| | - Xueqing Wang
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
| | - Tong Zhou
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
| | - Tianzuo Chen
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
| | - Ya Liu
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
| | - Chuanjun Ma
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
| | - Hongshan Guo
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
| | - Baozhong Li
- Dalian (Fushun) Research Institute of Petroleum and Petrochemical, Sinopec Corp, National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Dalian, 116045, China
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8
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Li F, Zhang P, Gong A, Zhang X, Zhang W, Li K. Cu particles confined in three-dimensional open porous carbon foam monolith as highly efficient electrode for electroreduction of nitrate with significant alleviation of nitrite. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Zou X, Chen C, Wang C, Zhang Q, Yu Z, Wu H, Zhuo C, Zhang TC. Combining electrochemical nitrate reduction and anammox for treatment of nitrate-rich wastewater: A short review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 800:149645. [PMID: 34399327 DOI: 10.1016/j.scitotenv.2021.149645] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/14/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Treatment of nitrate-rich wastewater is important but challenging for the conventional biological denitrification process. Here, we propose combining the electrochemical reduction and anaerobic ammonium oxidation (anammox) processes together for treatment of nitrate-rich wastewater. This article reviews the mechanism and current research status of electrochemical reduction of nitrate to ammonium as well as the mechanism and applicability of the anammox process. This article discusses the principles, superiorities and challenges of this combined process. The feasibility of the combined process depends on the efficiency of electrochemical nitrate reduction to ammonium and the conditions in the anammox process to use the reduced ammonium as the substrate to achieve deep nitrogen removal. The article provides a feasible strategy for using the electrochemical reduction and anammox combined process to treat nitrate-rich wastewater.
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Affiliation(s)
- Xinyi Zou
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China
| | - Chongjun Chen
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China; Tianping College of Suzhou University of Science and Technology, Suzhou 215009, PR China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215009, PR China.
| | - Changhong Wang
- Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215009, PR China; School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215011, PR China
| | - Qun Zhang
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China
| | - Zhuowei Yu
- Ecolord (Suzhou) Environment Protect Technology Co., Ltd, Suzhou 215011, PR China
| | - Haiping Wu
- Ecolord (Suzhou) Environment Protect Technology Co., Ltd, Suzhou 215011, PR China
| | - Chao Zhuo
- Ecolord (Suzhou) Environment Protect Technology Co., Ltd, Suzhou 215011, PR China
| | - Tian C Zhang
- Civil & Environmental Engineering Dept., University of Nebraska-Lincoln, Omaha, NE 68182-0178, USA
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10
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Benekos AK, Tziora FE, Tekerlekopoulou AG, Pavlou S, Qun Y, Katsaounis A, Vayenas DV. Nitrate removal from groundwater using a batch and continuous flow hybrid Fe-electrocoagulation and electrooxidation system. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 297:113387. [PMID: 34332344 DOI: 10.1016/j.jenvman.2021.113387] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/15/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
During the last two decades nitrate contaminated groundwater has become an extensive worldwide problem with wide-reaching negative effects on human health and the environment. In this study, a combination of electrocoagulation (EC) and electrooxidation (EO) was studied as a denitrification process to efficiently remove nitrates and ammonium (a by-product produced during EC) from real polluted groundwater. Initially, EC experiments under batch operating mode were performed using iron electrodes at different applied current density values (20-40 mA cm-2). Nitrate percentage removal of 100 % was recorded, however high ammonium concentrations were performed (4.5-6.5 mg NH4+-Ν L-1). Therefore, a continuous flow system was examined for the complete removal of both nitrates and EC-generated ammonium cations. The system comprised an EC reactor, a settling tank and an EO reactor. The applied current densities to the EC process were the same as those in the batch experiments, while the volumetric flow rates were 4, 6 and 8 mL min-1. Regarding the current density of the EO process was kept constant at the value of 75 mA cm-2. The percentage nitrate removal recorded during the EC process ranged between 52.0 and 100 %, while the NH4+-N concentration at the outlet of the EO reduced significantly (53-100 %) depending on the applied current density and the volumetric flow rate. Also, the dissolved iron concentration in the treated water was always below the legislated limit of 0.2 mg L-1 (up to 0.027 mg L-1). These results indicate that the proposed hybrid system is capable of denitrifying real nitrate contaminated groundwater without generating toxic by-products, therefore making the water suitable for human consumption.
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Affiliation(s)
- Andreas K Benekos
- Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece
| | - Foteini E Tziora
- Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece
| | | | - Stavros Pavlou
- Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece; Institute of Chemical Engineering Sciences (ICE-HT), Stadiou Str., Platani, GR-26504, Patras, Greece
| | - Yan Qun
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou, 215011, China
| | - Alexandros Katsaounis
- Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece
| | - Dimitris V Vayenas
- Department of Chemical Engineering, University of Patras, Rio, GR-26504, Patras, Greece; Institute of Chemical Engineering Sciences (ICE-HT), Stadiou Str., Platani, GR-26504, Patras, Greece
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11
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Zhang S, Chen X, Du S, Wang J, Dong J, Wu D. Facile synthesis of highly active Ti/Sb-SnO 2 electrode by sol-gel spinning technique for landfill leachate treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:1366-1378. [PMID: 34559072 DOI: 10.2166/wst.2021.336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Highly active Ti/Sb-SnO2 electrodes were fabricated using sol-gel spin coating procedure, which exhibited a rough, uniform and multilayer coating structure. The effects of different Sb-SnO2 film layers on the physiochemical, electrochemical properties and pollutant degradability of electrodes and the mechanism were evaluated on a systematic basis. The electrodes with more active layers exhibited higher electro-catalytic performance. Upon exceeding 8 layers, the promotion effect of the coating was reduced. Considering various factors, this paper recommends preparing Ti/Sb-SnO2 electrodes coated with 8 layers to obtain higher electro-catalytic ability in landfill leachate treatment. The specific number of coating layers should be determined according to the electrode requirements. This work provided a theoretical basis and technical support for the preparation of Ti-SnO2 electrodes with high electro-catalytic activity and stability, while it still remains a great challenge to achieve an excellent balance between performance and stability before Ti/Sb-SnO2 electrodes can be implemented on a large scale in wastewater treatment.
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Affiliation(s)
- Shuchi Zhang
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China E-mail:
| | - Xu Chen
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China E-mail:
| | - Shuwen Du
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China E-mail:
| | - Jingli Wang
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China E-mail:
| | - Jiayu Dong
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China E-mail:
| | - Donglei Wu
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058, China E-mail:
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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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13
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Cheng W, Guo C, Ke Q, Guo Y. Heavy Metal Ions in Wastewater Affect the Photodegradation of Phenol‐4‐sulfonic Acid over Biphasic TiO
2
/Activated Carbon Fiber Composites. ChemistrySelect 2021. [DOI: 10.1002/slct.202100296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Wu‐Kui Cheng
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai 200234 PR China
| | - Cui‐Xiang Guo
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai 200234 PR China
| | - Qin‐Fei Ke
- School of Materials Science and Engineering Shanghai Institute of Technology Shanghai 201418 China
| | - Ya‐Ping Guo
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai 200234 PR China
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