国家自然科学基金资助项目（50872105）
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Cd2+、Cu2+、Pb2+、Ni2+和Zn2+具有较好的修复效果,最佳修复时间为3～7d;前期（1～3d）,土壤修复体中的碱度较高,通过离子交换加速形成Cu(OH)2·2H2O、Ni(OH)2·2H2O和Zn(OH)2,该阶段离子交换占主导地位;中期（3～14d）,随着钢渣微粉中的Ca2SiO4水化加速，形成含水硅酸钙（CSH）,SiO4-4开始与Ni2+、Zn2+发生反应,此时离子交换和凝胶固化同时起作用;后期（14～28d）,钢渣微粉中的Ca2SiO4继续水化,形成大量CSH,SiO4-4与Ni2+、Zn2+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Ca2SiO4与Cd2+、Ni2+、Zn2+固化生成Cd2SiO4、Ni2SiO4、Zn2SiO4.
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 Cd2+, Cu2+, Pb2+, Ni2+ and Zn2+ in the polluted soil and the best repairing time is 37d. In the early stage(13d), the mixture of steel slag powder and heavy metals contaminated soil has a relatively high alkaline environment, and the formation of Cu(OH)2·2H2O, Ni(OH)2·2H2O and Zn(OH)2 is accelerated through ion exchange. At the middle stage(314d), with the accelerated hydration of Ca2SiO4 to form a gel(C S H), SiO4-4 begins to react with Ni2+ and Zn2+, at that time ion exchange and gel solidification play a role. In the later stage(1428d), Ca2SiO4 continue to hydrate to form a large amount of C S H, and SiO4-4 reacts with Ni2+ and Zn2+ 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 Ca2SiO4 solidified with Cd2+, Ni2+ and Zn2+ to form Cd2SiO4, Ni2SiO4 and Zn2SiO4.
杨刚,李辉,陈华.钢渣微粉对重金属污染土壤的修复及机理研究[J].建筑材料学报,2021,24(2):318-322
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