Yunmei Wei, Peng Song, Yi Wen, Qin Liao, Xiaoqi Du, Lianying Chen, Jialiang Liang, Gang Long, Takayuki Shimaoka
{"title":"深入分析硫酸根自由基和羟基自由基在金属氰化物络合物降解过程中的作用和机理","authors":"Yunmei Wei, Peng Song, Yi Wen, Qin Liao, Xiaoqi Du, Lianying Chen, Jialiang Liang, Gang Long, Takayuki Shimaoka","doi":"10.1016/j.watres.2024.122656","DOIUrl":null,"url":null,"abstract":"Persulfate-based advanced oxidation processes (PS-based AOPs), characterized by the coexistence of SO₄•⁻ and HO•, have been proven effective in treating a series of cyanide-bearing pollutants. However, the mechanisms of these reactive species in the degradation of cyanides, especially metal-cyanide complexes, remain unclear or contradictory. The degradation behavior of representative cyanides (including potassium cyanide and potassium ferricyanide) at different pH conditions (2, 7 and 12) in thermally activated persulfate system (T = 60°C) was explored, and the roles of SO₄•⁻ and HO• in cyanide degradation were explored by leveraging the distinct characteristics of reactive species under different pH conditions. The study found that both HO• and SO₄•⁻ can react with free cyanide (CN⁻ and HCN). However, the reaction barrier between CN⁻ and HO• is lower than that between HCN and SO₄•⁻, resulting in a higher removal rate of free cyanide under alkaline conditions compared to acidic and neutral conditions. For complexed cyanide, the complex bonds in ferricyanide were completely broken within 24 hours by thermally activated persulfate at pH 2, releasing free cyanide, indicating the effectiveness of SO₄•⁻ in breaking the Fe-C bonds in ferricyanide. In contrast, ferricyanide was barely decomposed at pH 12, implying the inefficacy of HO• in breaking the Fe-C bonds. This study also innovatively found that SO₄•⁻ breaks the Fe-C bonds by oxidizing Fe(Ⅲ) in ferricyanide to Fe(Ⅳ) or Fe(Ⅴ), releasing CN⁻, which is then converted to CNO⁻ by SO₄•⁻ and HO•. CNO⁻ is further mineralized to NO₃⁻, NH₄⁺, and N₂ through hydrolysis or oxidation reactions. This research clarifies, for the first time, the activity of SO₄•⁻ and HO• toward cyanide degradation in PS-based AOPs.","PeriodicalId":443,"journal":{"name":"Water Research","volume":null,"pages":null},"PeriodicalIF":11.4000,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"In-depth Analysis of the Roles and Mechanisms of Sulfate Radical and Hydroxyl Radical in the Degradation of Metal-Cyanide Complexes\",\"authors\":\"Yunmei Wei, Peng Song, Yi Wen, Qin Liao, Xiaoqi Du, Lianying Chen, Jialiang Liang, Gang Long, Takayuki Shimaoka\",\"doi\":\"10.1016/j.watres.2024.122656\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Persulfate-based advanced oxidation processes (PS-based AOPs), characterized by the coexistence of SO₄•⁻ and HO•, have been proven effective in treating a series of cyanide-bearing pollutants. However, the mechanisms of these reactive species in the degradation of cyanides, especially metal-cyanide complexes, remain unclear or contradictory. The degradation behavior of representative cyanides (including potassium cyanide and potassium ferricyanide) at different pH conditions (2, 7 and 12) in thermally activated persulfate system (T = 60°C) was explored, and the roles of SO₄•⁻ and HO• in cyanide degradation were explored by leveraging the distinct characteristics of reactive species under different pH conditions. The study found that both HO• and SO₄•⁻ can react with free cyanide (CN⁻ and HCN). However, the reaction barrier between CN⁻ and HO• is lower than that between HCN and SO₄•⁻, resulting in a higher removal rate of free cyanide under alkaline conditions compared to acidic and neutral conditions. For complexed cyanide, the complex bonds in ferricyanide were completely broken within 24 hours by thermally activated persulfate at pH 2, releasing free cyanide, indicating the effectiveness of SO₄•⁻ in breaking the Fe-C bonds in ferricyanide. In contrast, ferricyanide was barely decomposed at pH 12, implying the inefficacy of HO• in breaking the Fe-C bonds. This study also innovatively found that SO₄•⁻ breaks the Fe-C bonds by oxidizing Fe(Ⅲ) in ferricyanide to Fe(Ⅳ) or Fe(Ⅴ), releasing CN⁻, which is then converted to CNO⁻ by SO₄•⁻ and HO•. CNO⁻ is further mineralized to NO₃⁻, NH₄⁺, and N₂ through hydrolysis or oxidation reactions. This research clarifies, for the first time, the activity of SO₄•⁻ and HO• toward cyanide degradation in PS-based AOPs.\",\"PeriodicalId\":443,\"journal\":{\"name\":\"Water Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":11.4000,\"publicationDate\":\"2024-10-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Water Research\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.1016/j.watres.2024.122656\",\"RegionNum\":1,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, ENVIRONMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2024.122656","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
In-depth Analysis of the Roles and Mechanisms of Sulfate Radical and Hydroxyl Radical in the Degradation of Metal-Cyanide Complexes
Persulfate-based advanced oxidation processes (PS-based AOPs), characterized by the coexistence of SO₄•⁻ and HO•, have been proven effective in treating a series of cyanide-bearing pollutants. However, the mechanisms of these reactive species in the degradation of cyanides, especially metal-cyanide complexes, remain unclear or contradictory. The degradation behavior of representative cyanides (including potassium cyanide and potassium ferricyanide) at different pH conditions (2, 7 and 12) in thermally activated persulfate system (T = 60°C) was explored, and the roles of SO₄•⁻ and HO• in cyanide degradation were explored by leveraging the distinct characteristics of reactive species under different pH conditions. The study found that both HO• and SO₄•⁻ can react with free cyanide (CN⁻ and HCN). However, the reaction barrier between CN⁻ and HO• is lower than that between HCN and SO₄•⁻, resulting in a higher removal rate of free cyanide under alkaline conditions compared to acidic and neutral conditions. For complexed cyanide, the complex bonds in ferricyanide were completely broken within 24 hours by thermally activated persulfate at pH 2, releasing free cyanide, indicating the effectiveness of SO₄•⁻ in breaking the Fe-C bonds in ferricyanide. In contrast, ferricyanide was barely decomposed at pH 12, implying the inefficacy of HO• in breaking the Fe-C bonds. This study also innovatively found that SO₄•⁻ breaks the Fe-C bonds by oxidizing Fe(Ⅲ) in ferricyanide to Fe(Ⅳ) or Fe(Ⅴ), releasing CN⁻, which is then converted to CNO⁻ by SO₄•⁻ and HO•. CNO⁻ is further mineralized to NO₃⁻, NH₄⁺, and N₂ through hydrolysis or oxidation reactions. This research clarifies, for the first time, the activity of SO₄•⁻ and HO• toward cyanide degradation in PS-based AOPs.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.