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Li S, Yang Y, Zheng H, Zheng Y, Jing T, Ma J, Nan J, Leong YK, Chang JS. Advanced oxidation process based on hydroxyl and sulfate radicals to degrade refractory organic pollutants in landfill leachate. CHEMOSPHERE 2022; 297:134214. [PMID: 35257707 DOI: 10.1016/j.chemosphere.2022.134214] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/19/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
As a special type of wastewater produced in the landfill, leachate is mainly composed of organic pollutants, inorganic salts, ammonia nitrogen and heavy metals, and featured by high pollutants concentration, complex composition and large fluctuations in water quality and volume. Biological, chemical and physical methods have been proposed to treat landfill leachate, but much attention has been paid to the advanced oxidation processes (AOPs), due to their high adaptability and organic degradation efficiency. This paper summarizes the recent findings on the AOPs based on hydroxyl radical (OH) (e.g., ozonation and catalyzed ozone oxidations, Fenton and Fenton-like oxidations) and sulfate radical (SO4-) (e.g., activated and catalyzed persulfate oxidations), especially the production routes of free radicals and mechanisms of action. When dealing with some special landfill leachates, it is difficult for a single advanced oxidation technology to achieve the expected results, but the synergistic combination with biological or physical methods can produce satisfactory outcomes. Therefore, this paper has summarized the application of these combined treatment technologies on landfill leachate.
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Affiliation(s)
- Shuo Li
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China; Urban Water Resources Development and Northern National Engineering Research Center, Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Yalun Yang
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Heshan Zheng
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China.
| | - Yongjie Zheng
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Tao Jing
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Jun Ma
- Urban Water Resources Development and Northern National Engineering Research Center, Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jun Nan
- Urban Water Resources Development and Northern National Engineering Research Center, Harbin, 150090, China; School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Yoong Kit Leong
- Department of Chemical and Materials Engineering, Tunghai University, Taichung, 407, Taiwan
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taichung, 407, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan, 701, Taiwan; Research Center for Energy Technology and Strategy Center, National Cheng Kung University, Tainan, 701, Taiwan.
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Assessment of Pretreatments for Highly Concentrated Leachate Waters to Enhance the Performance of Catalytic Wet Peroxide Oxidation with Sustainable Low-Cost Catalysts. Catalysts 2022. [DOI: 10.3390/catal12020238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Matured compost, derived from a mechanical and biological treatment (MBT) plant, was used as a precursor to produce catalysts through hydrothermal and thermal carbonization, HC and PC, respectively. HC and PC displayed suitable properties to act as catalysts in the catalytic wet peroxide oxidation (CWPO) treatment of the highly polluted leachate waters generated in the same MBT plant (TOC0 = 27 g L−1; COD0 = 60 g L−1; BOD5,0 = 23 g L−1). The influence of catalyst loading and pH were studied, considering multiple additions of H2O2. The best experimental conditions found were T = 80 °C, pH0 = 3.0, 7.2 g L−1 of HC catalyst, 85.7 g L−1 of H2O2, added in five batches in one-hour intervals between each addition. Under these experimental conditions, removals of 43%, 52%, 93%, 82%, 35%, 95% and 93% for the COD, TOC, BOD5, aromaticity, chlorides, turbidity and color number (CN) were, respectively, observed. Ion exchange resins and coagulation–flocculation were studied as pretreatment options to reduce the complexity of the leachate waters and enhance the CWPO results. Both strategies resulted in higher mineralization and enhanced the consumption efficiency of H2O2 (ηH2O2). The sequential treatment using coagulation–flocculation and CWPO with PC catalyst showed the best results, achieving abatement of 94%, 70%, 98%, 93%, 31%, 96% and 95% for COD, TOC, BOD5, aromaticity, chlorides, turbidity and CN, respectively.
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Qin H, Chen H. Pretreatment of concentrated leachate by the combination of coagulation and catalytic ozonation with Ce/AC catalyst. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2016; 73:511-519. [PMID: 26877032 DOI: 10.2166/wst.2015.508] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A raw concentrated leachate produced from membrane bioreactor-nanofiltration (MBR-NF) was taken from Chengdu Chang'an Waste Landfill Site, China. The major fraction of this concentrated leachate was large refractory humic substances. A coagulation-ozonation process was applied to treat this leachate, aiming at enhancing chemical oxygen demand (COD) removal efficiency and increasing its biodegradability. Meanwhile the molecular size distribution of the leachate, before and after coagulation and ozonation treatment, was analyzed by using ultrafiltration membrane separation. Coagulation pretreatment effectively removed varieties of large molecules in the raw concentrated leachate. The addition of Ce/AC greatly improved the oxidative ability of O3 in COD removal in the ozonation of coagulated leachate. The biochemical oxygen demand (BOD5)/COD ratio increased from 0.011 for the untreated concentrated leachate to 0.30 for the effluent of the coagulation-catalytic ozonation process, which indicated that a subsequent biological treatment could be readily conducted. The stability test demonstrated that the Ce/AC catalyst was effective and stable in the catalytic ozonation process. According to the results of molecular size distribution analysis, a direct correlation was observed between the increase of BOD5/COD and the decrease of apparent molecular weight.
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Affiliation(s)
- Hangdao Qin
- College of Material and Chemical Engineering, Tongren University, Tongren 554300, China E-mail:
| | - Honglin Chen
- Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China
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