微波耦合硫酸亚铁对铬渣的稳定化效果和机制研究  

The Stabilization Efficiency and Mechanism towards Chromium Residue by Microwave and FeSO_(4)Treatment

作　　者：郑敏慧 张凤姣 郭沨 李瑜玥 王琳玲[1] 盛安旭 昝飞翔 吴晓晖[1] 陈静[1] ZHENG Minhui;ZHANG Fengjiao;GUO Feng;LI Yuyue;WANG Linling;SHENG Anxu;ZAN Feixiang;WU Xiaohui;CHEN Jing(Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin,School of Environmental Science&Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Gezhouba Group Eco-environmental Protection Co.Ltd.,Wuhan 430070,China)

机构地区：[1]长江流域多介质污染协同控制湖北省重点实验室,华中科技大学环境科学与工程学院,湖北武汉430074 [2]葛洲坝集团生态环保有限公司,湖北武汉430070

出　　处：《环境科学与技术》2024年第9期74-81,共8页Environmental Science & Technology

基　　金：国家自然科学基金项目(42277014);中国能源建设股份有限公司重大科技项目(CEEC2021-ZDYF-17)。

摘　　要：安全处置的铬渣常出现“返黄”现象,这与未溶解的含六价铬(Cr(Ⅵ))矿物再次释放Cr(Ⅵ)有关,因此在修复过程中,彻底溶解不稳定的含Cr(Ⅵ)矿物,使其充分释放Cr(Ⅵ)是实现铬渣长效稳定的关键。该研究利用微波(MW)快速溶解铬渣中Cr(Ⅵ)矿物——钙钒石,再耦合硫酸亚铁(FeSO_(4))实现了铬渣的高效稳定。MW辐照显著降低了钙矾石溶解的表观活化能(35.8 k J/mol),促进钙矾石快速溶解释放Cr(Ⅵ)。而FeSO_(4)水解酸化产生的硫酸(H2SO_(4))在MW场下进一步促进了含Cr(Ⅵ)矿物水滑石的溶解,实现了铬渣中Cr(Ⅵ)矿物的完全溶解。同时,MW显著提升了FeSO_(4)对Cr(Ⅵ)的还原效率,在低功率MW(462 W)耦合低剂量FeSO_(4)(w=21.5%)处理下,Cr(Ⅵ)的还原率达到100%。更为重要的是,MW促进了生成的三价铬(Cr(Ⅲ))固定在Cr(Ⅲ)矿物(Fe O·Cr_(2)O_(3)和Cr_(2)O_(3))晶格中,1年后未出现“返黄”,实现了铬渣的长效稳定。该研究为MW耦合FeSO_(4)在铬渣稳定化处理领域的应用提供了数据支持和理论基础。The“returning to yellow”phenomenon usually occurs in treated chromium residue,which is related to the rerelease of Cr(Ⅵ)in undissolved Cr(Ⅵ)-bearing minerals.In this regard,the complete dissolution of unstable Cr(Ⅵ)-bearing minerals and the release of Cr(Ⅵ)are crucial to the long-term stability of chromium residue.In this study,the dissolution of ettringite was facilitated by microwave(MW),and then the efficient stabilization of chromium residue was achieved via MW combined with FeSO_(4)treatment.In general,the apparent activation energy of ettringite dissolution(35.8 kJ/mol)was significantly reduced by MW irradiation,and hence promoting the rapid dissolution of ettringite to release Cr(Ⅵ).Furthermore,the dissolution of hydrotalcite was promoted by H2SO_(4)from FeSO_(4)hydrolysis in MW field,leading to the complete dissolution of Cr(Ⅵ)-bearing minerals in chromium residue.Moreover,the reduction efficiency of Cr(Ⅵ)by FeSO_(4)was significantly improved by MW,which reached up to 100%with the treatment of MW(462 W)combined with low dose FeSO_(4)(w=21.5%).More importantly,the formation of crystalline Cr(Ⅲ)-bearing minerals,including FeO·Cr_(2)O_(3)and Cr_(2)O_(3)were promoted by MW irradiation.There was no“returning to yellow”phenomenon occurred after one year.The stabilization and safe disposal of chromium residue was obtained.Therefore,this study provided data support and theoretical basis for the application of MW-coupled FeSO_(4)treatment in the field of chromium residue stabilization.

关 键 词：微波 铬渣 促溶 硫酸亚铁 稳定化 

分 类 号：X131[环境科学与工程—环境科学]