造粒堆浸在粉质黏土重金属污染修复中的应用  

Application of granulated heap leaching in remediation of heavy metal contaminated silty clay

作　　者：郭丹花 刘泽峰 初亚飞 何苏祺 GUO Danhua;LIU Zefeng;CHU Yafei;HE Suqi(Fujian Longking Co.,Ltd.,Longyan 364000,China)

机构地区：[1]福建龙净环保股份有限公司,福建龙岩364000

出　　处：《化工环保》2023年第3期409-415,共7页Environmental Protection of Chemical Industry

基　　金：龙岩市科技计划项目(2020LYF17003)。

摘　　要：针对粉质黏土对重金属的强吸附性导致淋洗修复难度大的问题,以某Pb污染场地的粉质黏土为研究对象,开展了造粒堆浸实验。加入0.06%(w)的无患子皂苷作为黏结剂造粒制得的球团,抗压碎力为65.87 N,堆浸240 h未发生崩解,满足堆浸要求。造粒可改善堆体的渗透性,240 h时堆体的渗透速率由5.50 L/(m^(2)·h)大幅提升至22.66 L/(m^(2)·h)。以4.00%(w)FeCl_(3)-5.00%(w)一水柠檬酸混合液作为堆浸液,水土比控制在1.5∶1,当土壤球团粒径1~4 mm、筑堆高度1.5~2.0 m、注液速率20 L/(m^(2)·h)时对Pb的去除效果最优,去除率可达71.65%。对Pb污染土壤造粒堆浸的动力学过程较符合双常数方程,表明该过程具有土壤吸附特征。Aiming at the difficulty of leaching and remediation of silty clay due to the strong adsorption of heavy metals,the granulation heap leaching experiment was carried out taking the silty clay of a Pb contaminated site as the research object.Sapindoside using as binder was added into the silty clay for Granulation with 0.06%(w).The prepared granules with 65.87 N of resistance force to crushing and without disintegration after heap leaching for 240 h can meet the requirements for heap leaching.The permeability of the stack can be improved by granulation,and the permeation rate of the stack at 240 h is greatly increased from 5.50 L/(m^(2)·h)to 22.66 L/(m^(2)·h).Using the mixture of 4.00%(w)FeCl_(3)and 5.00%(w)citric acid monohydrate as heap leaching solution and controlling the ratio of soil to water at 1.5∶1,the removal effect of Pb is optimal when the particle size of soil pellet is 1-4 mm,the height of granulated heap is 1.5-2.0 m and the injection rate is 20 L/(m^(2)·h),and the leaching rate of Pb in silty clay can reach 71.65%.The kinetic process of granulation heap leaching of Pb-contaminated soil is more consistent with the two-constant equation,indicating that the process has the characteristics of soil adsorption.

关 键 词：造粒堆浸 粉质黏土 重金属污染 无患子皂苷 淋洗动力学 铅 

分 类 号：X53[环境科学与工程—环境工程]