污泥-凹凸棒石共热解生物炭对矿区土壤重金属生物有效性和环境风险的影响  

Influences of Biochar Prepared by Co-pyrolysis with Sludge and Attapulgite on Bioavailability and Environmental Risk of Heavy Metals in Mining Soil

作　　者：陶玲[1,2,3] 黄磊 周怡蕾[1,2] 李中兴 任珺 TAO Ling;HUANG Lei;ZHOU Yilei;LI Zhongxing;REN Jun(Key Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou Jiaotong University,Lanzhou 730070,P.R.China;School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,P.R.China;Gansu Hanxing Environmental Protection Co.,Ltd.,Lanzhou,730070,P.R.China;Gansu Haoyu Environmental Protection Co.Ltd.,Lanzhou 730070,P.R.China)

机构地区：[1]甘肃省黄河水环境重点实验室,兰州交通大学,甘肃兰州730070 [2]兰州交通大学环境与市政工程学院,环境生态研究所,甘肃兰州730070 [3]甘肃瀚兴环保科技有限公司,甘肃兰州730070 [4]甘肃昊宇环保科技有限公司,甘肃天水741020

出　　处：《生态环境学报》2022年第8期1637-1646,共10页Ecology and Environmental Sciences

基　　金：甘肃省黄河水环境重点实验室基金(20JR2RA002,21YRWEK007,21YRWEG003);甘肃省教育厅产业支撑计划项目(2021CYZC-31);兰州市人才创新创业项目(2021-RC-41);甘肃省科技厅民生科技专项(2019-0304-SFC-0011)。

摘　　要：全国部分地区重金属污染土壤问题严重,生物炭作为土壤修复材料,其在土壤重金属的治理中具有重要的作用。为探讨不同添加量的污泥-凹凸棒石共热解生物炭对土壤中重金属的钝化效果,在矿区重金属污染土壤中添加不同比例的凹凸棒石(0,5%,10%,15%,20%,25%,30%)和污泥共热解制备污泥生物炭,进行钝化修复实验,从而降低土壤中重金属转移的风险。结果表明,污泥生物炭增加了土壤的pH值,显著提高了钝化土壤的阳离子交换量(CEC)和电导率(EC),降低了土壤中重金属的DTPA提取态和TCLP提取态含量,明显促进了土壤中Cd和Zn由酸溶态向残渣态转变。其中20%凹凸棒石添加量制备的污泥生物炭对重金属Cu和Cd钝化效果较好,残渣态Cu显著提高了19.27%,还原态Cd降低了12.5%。15%凹凸棒石添加量制备的污泥生物炭对重金属Cr、Zn和Ni钝化效果较好,酸溶态Cr、Zn和Ni分别显著地降低了38.41%、38.39%和25.4%,同时凹凸棒石和污泥共热解决生物炭明显降低了土壤中重金属转移的风险,钝化效率达到了94.09%。20%凹凸棒石添加污泥制备的污泥生物炭在重金属污染土壤的工程修复领域具有一定的应用潜力。Sludge biochar was prepared by using co-pyrolysis of sludge and different amounts of attapulgite. The passivation and remediation experiment was carried out by adding heavy metal contaminated soil in a mining area. The results showed that sludge biochar increased the pH value of soil and significantly increased the cation exchange capacity(CEC) and electrical conductivity(EC)of passivated soil. The contents of DTPA extracted and TCLP extracted heavy metals in soil were reduced, and the transformation of CD and Zn from acid soluble state to residual state was significantly promoted. The sludge biochar prepared with 20% attapulgite addition had a good passivation effect on heavy metals Cu and CD, the residual Cu was significantly increased by 19.27%, and the reduced CD was reduced by 12.5%. The sludge biochar prepared with 15% attapulgite addition had a good passivation effect on heavy metals Cu and CD. The passivation effect of heavy metals Cr, Zn and Ni is beneficial, and the acid soluble Cr, Zn and Ni were significantly reduced by 38.41%, 38.39% and 25.4%. At the same time, the co-heating of attapulgite and sludge solved the biochar,significantly reducing the risk of heavy metal transfer in soil, and the passivation efficiency reached 94.09%. The sludge biochar prepared by adding sludge with 20% attapulgite has certain potential to be utilized in the field of engineering remediation of heavy metal contaminated soil.

关 键 词：重金属 污泥 凹凸棒石 钝化 生物炭 

分 类 号：X52[环境科学与工程—环境工程]