电厂脱硫产物中痕量元素形态及毒性浸出特性  

The Occurrence Forms and Toxic Leaching Characteristics of Trace Elements in Desulfurization by Products of Coal-fired Power Plants

作　　者：王润芳 朱文荪 水玉蝶 姚为方 邢琛 马大卫 孔明 王若民 杨娴 孙梅[3] WANG Runfang;ZHU Wensun;SHUI Yudie;YAO Weifang;XING Chen;MA Dawei;KONG Ming;WANG Ruomin;YANG Xian;SUN Mei(Anhui Xinli Power Technology Consulting Limited Liability Company,Hefei 230601,China;School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China;Anhui Province Key Laboratory of Polar Environment and Global Change,University of Science and Technology of China,Hefei 230026,China;State Grid Anhui Electric Power Corporation Research Institute,Hefei 230601,China)

机构地区：[1]安徽新力电业科技咨询有限责任公司,合肥230601 [2]广东工业大学材料与能源学院,广州510006 [3]中国科学技术大学极地环境与全球变化重点实验室,合肥230026 [4]国网安徽省电力有限公司电力科学研究院,合肥230601

出　　处：《科技和产业》2024年第7期123-129,共7页Science Technology and Industry

基　　金：安徽新力电业基金(2020咨-KJ-03);国家自然科学基金(41976220);中国科学院战略性先导科技专项(XDB40010200)。

摘　　要：燃煤电厂副产物脱硫石膏和污泥在雨水中或作为固体废弃物加工过程中,吸附的痕量元素会再次进入环境中,造成二次污染。选取安徽省3个典型燃煤电厂超低排放机组,通过欧洲共同体标准物质局(BCR)逐级提取法测定脱硫污泥和石膏中Cr、As、Cd和Pb的赋存形态,应用标准毒性浸出程序法(TCLP)对脱硫石膏的浸出毒性进行测定,分析脱硫副产物中Cr、As、Cd和Pb的潜在环境影响。结果表明:脱硫污泥中4种元素的质量浓度明显高于脱硫石膏;脱硫石膏中Cr和As稳定性高,Cd和Pb元素有效态占比大于50%,迁移能力强,对生态环境具有潜在的风险;脱硫污泥中Cr、Cd和As的迁移能力较强,环境风险较高,其中Cr在氧化环境中不稳定,Cd在酸性环境中更易浸出,As在氧化和还原环境中均不稳定;pH和固液比对石膏中重金属浸出有重要影响,不同元素之间存在较大差异;Pb、Cr和As浸出率随着pH的降低而增大,随液固比的增大而增大,并逐渐达到平衡;Cd的最大浸出率低于其他3种元素,浸出率与pH和固液比的相关性较弱,在pH为4.47时,浸出率较高。研究结果可为燃煤电厂脱硫副产物处置及再利用提供参考。The by-products of coal-fired power plants,such as desulfurization gypsum and sludge,can adsorb trace elements into the environment again during rainwater or solid waste processing,causing secondary pollution.Three typical coal-fired power plants with ultra-low emissions were selected in Anhui Province,and the occurrence forms of Cr,As,Cd,and Pb in desulfurization sludge and gypsum were determined using the European Community Bureau of Referenee(BCR)stepwise extraction method.The leaching toxicity of desulfurization gypsum was determined using the toxicity characteristic leaching procedure(TCLP)standard toxicity leaching method,and the potential environmental impact of Cr,As,Cd,and Pb in desulfurization by-products was analyzed.The results show that the mass concentration of elements in desulfurization sludge was significantly higher than that in desulfurization gypsum.The stability of Cr and As in desulfurization gypsum is higher,and the effective states of Cd and Pb elements account for more than 50%with stronger migration ability and potential risks to the ecological environment.The migration ability of Cr,Cd,and As is stronger in desulfurization sludge,and their environmental risk is higher.Cr is unstable in oxidizing environments,Cd is more easily leached in acidic environments,and As is unstable in both oxidizing and reducing environments.pH and solid-liquid ratio have important effects on the leaching of heavy metals in gypsum,and there are significant differences between different elements.The leaching rates of Pb,Cr,and As increase with the decrease of pH,increase with the liquid-solid ratio,and gradually reach equilibrium.The maximum leaching rate of Cd is lower than the other three elements,and the correlation between leaching rate and pH and solid-liquid ratio is weak.When pH is 4.47,the leaching rate is higher.The results can provide the reference for disposal and reuse of desulphurization byproducts in coal-fired power plants.

关 键 词：湿法脱硫 脱硫副产物 痕量元素 欧洲共同体标准物质局(BCR) 标准毒性浸出程序法(TCLP) 

分 类 号：X351[环境科学与工程—环境工程]