钢渣微粉对重金属污染土壤的修复及机理研究  

Remediation of Heavy Metals Contaminated Soil by Steel Slag Powder and Its Mechanism

作　　者：杨刚 李辉[1] 陈华[1,2] YANG Gang;LI Hui;CHEN Hua(College of Materials Science and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;MCC Baosteel Technology Services Co.,Ltd.,Shanghai 201999,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,陕西西安710055 [2]中冶宝钢技术服务有限公司,上海201999

出　　处：《建筑材料学报》2021年第2期318-322,共5页Journal of Building Materials

基　　金：国家自然科学基金资助项目(50872105)。

摘　　要：将转炉滚筒钢渣微粉(简称钢渣微粉)与重金属污染土壤混合,制备得到土壤修复体.利用X射线衍射(XRD)和傅里叶红外光谱(FTIR)对土壤修复体样品进行分析测试,以探讨钢渣微粉对重金属污染土壤的修复机理.结果表明:钢渣微粉对重金属污染土壤中的Cd^(2+)、Cu^(2+)、Pb^(2+)、Ni^(2+)和Zn^(2+)具有较好的修复效果,最佳修复时间为3~7 d;前期(1~3 d),土壤修复体中的碱度较高,通过离子交换加速形成Cu(OH)2·2H 2 O、Ni(OH)2·2H 2 O和Zn(OH)2,该阶段离子交换占主导地位;中期(3~14 d),随着钢渣微粉中的Ca 2 SiO_(4)水化加速,形成含水硅酸钙(C-S-H),SiO_(4)-4开始与Ni^(2+)、Zn^(2+)发生反应,此时离子交换和凝胶固化同时起作用;后期(14~28 d),钢渣微粉中的Ca 2 SiO_(4)继续水化,形成大量C-S-H,SiO_(4)-4与Ni^(2+)、Zn^(2+)反应成为主导,该阶段凝胶固化占主导地位,土壤修复体中OH-浓度下降,水化较多的Ca 2 SiO_(4)与Cd^(2+)、Ni^(2+)、Zn^(2+)固化生成Cd 2 SiO_(4)、Ni_(2)SiO_(4)、Zn_(2)SiO_(4).To mix the converter roller steel slag powder with heavy metals contaminated soil,the remediation effect of steel slag powder on heavy metals contaminated soil were tested by X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR)to elucidate the mechanism of remediation.The results show that the steel slag powder has a good repairing effect on Cd^(2+),Cu^(2+),Pb^(2+),Ni^(2+)and Zn^(2+)in the polluted soil and the best repairing time is 37 d.In the early stage(13 d),the mixture of steel slag powder and heavy metals contaminated soil has a relatively high alkaline environment,and the formation of Cu(OH)2·2H_(2)O,Ni(OH)2·2H_(2)O and Zn(OH)2 is accelerated through ion exchange.At the middle stage(314 d),with the accelerated hydration of Ca 2 SiO_(4)to form a gel(C-S-H),SiO_(4)-4 begins to react with Ni^(2+)and Zn^(2+),at that time ion exchange and gel solidification play a role.In the later stage(1428 d),Ca 2 SiO_(4)continue to hydrate to form a large amount of C-S-H,and SiO_(4)-4 reacts with Ni^(2+)and Zn^(2+)to become the dominant reaction.In the later stage,the concentration of OH-in the mixture of steel slag powder and heavy metals contaminated soil decreases in the gel solidification,and the more hydrated Ca 2 SiO_(4)solidified with Cd^(2+),Ni^(2+)and Zn^(2+)to form Cd 2 SiO_(4),Ni_(2)SiO_(4)and Zn_(2)SiO_(4).

关 键 词：钢渣微粉 重金属污染土壤 X射线衍射 傅里叶红外光谱 修复机理 

分 类 号：TU528.041[建筑科学—建筑技术科学]