污泥-凹凸棒石共热解生物炭对矿区重金属污染土壤的钝化修复效果研究  

Stabilization remediation of soil polluted by heavy metals using biochar prepared by co-pyrolysis with sludge and attapulgite

作　　者：陶玲[1,2,3] 马奔 李中兴 周怡蕾 任珺 TAO Ling;MA Ben;LI Zhongxing;ZHOU Yilei;REN Jun(Key Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou Jiaotong University,Lanzhou 730070,China;School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Institute of Environmental Ecology,Lanzhou 730070,China;Gansu Hanxing Environmental Protection Co.,Ltd.,Lanzhou 730070,China;Gansu Haoyu Environment Protection Co.,Ltd.,Tianshui 741020,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,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,兰州730070 [3]甘肃瀚兴环保科技有限公司,兰州730070 [4]甘肃昊宇环保科技有限公司,甘肃天水741020

出　　处：《农业环境科学学报》2022年第6期1251-1260,共10页Journal of Agro-Environment Science

基　　金：甘肃省黄河水环境重点实验室开放基金(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：通过钝化实验研究了在污泥中添加不同质量比(0、5%、10%、15%、20%、25%、30%)的凹凸棒石后制备的污泥-凹凸棒石共热解生物炭对矿区污染土壤中重金属的控制效应。结果表明:在矿区重金属污染土壤中添加污泥-凹凸棒石共热解生物炭后,土壤pH值随凹凸棒石添加量的增加而呈增加趋势,土壤电导率和阳离子交换量也整体呈现出上升的状态。加入污泥-凹凸棒石共热解生物炭钝化处理后,矿区污染土壤中Cu、Cd、Ni、Zn、Cr的TCLP提取态重金属含量均呈现下降趋势,钝化效率分别为94.71%、95.60%、91.75%、99.03%、96.65%;除Cu的DTPA提取态含量增加了5.93%~24.97%外,Cd、Ni、Zn、Cr的DTPA提取态含量也均有所降低,钝化效率分别为94.32%、94.75%、86.63%、90.02%、92.54%。酸溶态的Cd、Cu、Ni、Zn、Cr也向更加稳定的残渣态转化,其修复效率分别为42.50%、33.87%、57.92%、33.74%、42.36%,重金属的4种形态之和与重金属总量具有良好的一致性,一致率为82%~105%。根据土壤管控标准风险等级,重金属污染土壤钝化处理后,Cd、Cu、Ni、Zn、Cr均保持在低风险水平。Cd、Cu、Ni和Zn的潜在风险指数降低,虽然Cr的潜在风险指数有所升高,但是在所有处理条件下Cr的污染等级均为轻度。研究表明,在污泥中添加凹凸棒石增强了污泥生物炭对重金属的钝化性能。The stabilization effect of sludge and attapulgite co-pyrolytic biochar prepared by adding attapulgite with different mass ratios(0,5%,10%,15%,20%,25%,30%)on heavy metals in the polluted soil of mining area was studied by stabilization experiment.The results showed that the addition of sludge-attapulgite co-pyrolytic biochar to the soil contaminated by heavy metals in the mining area,the soil pH value gradually increased with the increase of attapulgite content in biochar,the soil electrical conductivity and cation exchange capacity increased as well as.After stabilization of heavy metal contaminated soil by heavy metals in the mining area with biochar prepared by co-pyrolysis with sludge and attapulgite,the contents of heavy metals extracted by TCLP of Cd,Cu,Ni,Zn and Cr all showed a decreasing trend.Except for the contents of heavy metals extracted by DTPA of Cu increased by 5.93%~24.97%,the contents of heavy metals extracted by DTPA of Cd,Ni,Zn and Cr also decreased.The stabilization efficiency of Cu,Cd,Ni,Zn and Cr extracted by DTPA and TCLP were 94.32%and 94.71%,94.75%and 95.60%,86.63%and 91.75%,90.02%and 99.03%,92.54%and 96.65%,respectively.The acid-soluble Cd,Cu,Ni,Zn and Cr were also converted to a more stable residue state,and the repair efficiency was 42.50%,33.87%,57.92%,33.74%,42.36%,respectively.The sum of the four forms of heavy metals was in good agreement with the total amount of heavy metals,and the percentage recovery of heavy metals was between 82%and 105%.According to the standard risk grade of soil control,after passivation treatment of heavy metal contaminated soil,Cd,Cu,Ni,Zn and Cr were all at a low risk level.The potential risk index of Cd,Cu,Ni and Zn decreased,although the potential risk index of Cr increased,but the pollution level of Cr under all treatments was mild pollution.The results indicated that the addition of attapulgite enhances the stabilization function of sludge biochar and provides a new method for the rational utilization of sludge.

关 键 词：污泥 凹凸棒石 生物炭 钝化 重金属 

分 类 号：X53[环境科学与工程—环境工程]