MICP技术联合多孔硅吸附材料对锌铅复合污染土固化/稳定化修复的试验研究  

Experimental study on zinc-lead composite contaminated soil solidified/stabilized by MICP technology combined with porous silicon adsorption materials

作　　者：李驰[1] 田蕾 董彩环 张永锋[2] 王燕星[1,3] LI Chi;TIAN Lei;DONG Cai-huan;ZHANG Yong-feng;WANG Yan-xing(College of Civil Engineering,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010051,China;College of Chemical Engineering,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010051,China;College of Science,Inner Mongolia University of Technology,Hohhot,Inner Mongolia 010051,China)

机构地区：[1]内蒙古工业大学土木工程学院,内蒙古呼和浩特010051 [2]内蒙古工业大学化工学院,呼和浩特010051 [3]内蒙古工业大学理学院,内蒙古呼和浩特010051

出　　处：《岩土力学》2022年第2期307-316,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51968057);内蒙古自治区科技计划关键技术攻关项目(No.2021GG0344);内蒙古自治区科技重大专项(No.2020ZD0021)。

摘　　要：近年来,工业和科技的快速发展使得重金属污染土固化/稳定化的修复研究成为热点。运用微生物诱导碳酸钙沉淀(MICP)技术联合吸附材料对锌铅复合重金属污染土进行固化/稳定化的修复,通过无侧限抗压强度试验、毒性浸出试验,评价处理前后污染土的固化效果与重金属的稳定化效果,结合扫描电镜(SEM)和X射线衍射(XRD)等检测手段,揭示MICP技术处理锌铅重金属污染土的修复机制。研究结果表明,采用MICP技术对锌铅重金属污染土进行固化/稳定化之后,可以有效降低污染土中有害重金属的浸出性。当矿化时间为10d时,试样无侧限抗压强度为942.5k Pa;铅的浸出浓度为4.20mg/L,比未处理时降低了44.81%;锌的浸出浓度为4.31mg/L,比未处理时降低了46.19%,效果显著。在此基础上,添加10%的多孔硅吸附材料后,试样无侧限抗压强度可达到1 021 kPa,强度提高了8.3%;铅的浸出浓度为2.45mg/L,与未经处理时相比,降幅达到了67.81%,与单纯MICP方法处理时相比,铅浸出浓度被二次降低了41.67%;锌的浸出浓度仅为2.93 mg/L,与未经处理时相比,降幅达到了63.4%,与单纯MICP方法处理时相比,浸出浓度被二次降低了31.9%。多孔硅吸附材料的添加明显提升了MICP技术对锌铅复合重金属污染土的修复效果,由于多孔硅吸附材料对重金属离子的固定与吸附,污染土中重金属的浸出浓度减小,同时,吸附材料还可以作为碳酸钙晶体沉积的核位点,加速矿化反应。该研究提出了处理重金属污染土的新技术并揭示了其修复机制,为MICP技术联合多孔硅吸附材料对现场锌铅复合重金属污染土的修复与应用提供了理论与试验依据。In recent years, the remediation of heavy metal contaminated soil has become a hot topic, due to the rapid development of industry and technology. In this study, MICP technology combined with adsorption materials was used to repair the zinc-lead composite heavy metal contaminated soil. Through unconfined compressive strength test and toxicity leaching test, the solidification effect of contaminated soil and the stabilization effect of heavy metals before and after treatment were evaluated. Combined with scanning electron microscope(SEM) and X ray diffraction(XRD) detection methods, the repairing mechanism of zinc-lead heavy metal contaminated soil treated by MICP technology was revealed. The results showed that the solidification/stabilization of Zn-Pb heavy metal contaminated soil by MICP technology effectively reduced the leaching of harmful heavy metals from contaminated soil.When the mineralization time was 10 d, the unconfined compressive strength of the sample was 942.5 kPa. The leaching concentration of lead was 4.20 mg/L, which was 44.81% lower than that of the untreated sample. The leaching concentration of zinc was 4.31 mg/L, which was 46.19% lower than that without treatment. On this basis, by adding 10% porous silicon adsorption material, the unconfined compressive strength of the sample could reach 1 021 kPa, and the strength was increased by 8.3%. The leaching concentration of lead was 2.45 mg/L, which was 67.81% lower than that without treatment. Compared with the MICP method alone, the leaching concentration of lead was reduced by 41.67%. The leaching concentration of zinc was only 2.93 mg/L,which decreased by 63.4% compared with that without treatment. Compared with the MICP method alone, the leaching concentration of zinc was reduced by 31.9%. The addition of porous silicon adsorption material significantly improved the remediation effect of MICP technology on zinc-lead composite heavy metal contaminated soil. Due to the immobilization and adsorption of heavy metal ions by porous silicon adsorpt

关 键 词：微生物诱导碳酸钙沉淀(MICP) 锌铅复合污染土 多孔硅吸附材料 固化/稳定化 修复机制 

分 类 号：X53[环境科学与工程—环境工程]