固化材料复配处理高浓度重金属复合污染土试验研究  

Experimental study of high concentration heavy metals co-contaminated soils stabilized with new product-based binders

作　　者：夏威夷 杜成磊 丁亮 蔡光华 曲常胜 XIA Weiyi;DU Chenglei;DING Liang;CAI Guanghua;QU Changsheng(Jiangsu Province Ecology and Environment Protection Engineering Research Center of Groundwater Pollution Prevention and Control,Jiangsu Environmental Engineering Technology Co.,Ltd.,Nanjing 210036,China;Jiangsu Environmental Protection Group Co.,Ltd.,Nanjing 210036,China;School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]江苏省环境工程技术有限公司江苏省生态环境保护地下水污染防治工程技术中心,南京210036 [2]江苏省环保集团有限公司,南京210036 [3]南京林业大学土木工程学院,南京210037

出　　处：《安全与环境学报》2024年第7期2797-2810,共14页Journal of Safety and Environment

基　　金：江苏省自然科学基金面上项目(BK20221565);江苏省环保集团科技项目(JSEP-TZ-2021-1009 RE,JSEP-TZ-2022-2002-RE);江苏省环境工程技术有限公司科研项目(JSEP-GJ20220012-RE-ZL);国家重点研发计划专项(2023YFC3709600);江苏省“333人才”优秀青年人才项目(2022年第六期);国家自然科学基金项目(41902276)。

摘　　要：针对人工配置的高质量比重金属复合污染土,分别开展工业废弃物、废弃生物质和矿物材料固化土的浸出毒性和pH值测试,发现不同固化原料对重金属Pb、Zn、Cd、As的固化效果存在明显的选择性;综合考虑原料生产的经济性、友好性和能耗指标,在优选出的固化原料基础上,复配形成了两种经济高效的复配固化剂B1和复配固化剂B2;以真实高质量比污染土为修复对象,开展复配固化剂固化效果、长期稳定性测试,以及固化土体pH值、无侧限抗压强度、渗透系数测试。试验结果显示:复配固化剂B1和复配固化剂B2对4种重金属均具有较好的固定效果,各掺量下重金属固化率均高于80%,且固化率随着掺量的增大而增大;复配固化剂B1对Pb、Zn和Cd的固定效果优于复配固化剂B2,而复配固化剂B2对于As的固定效果优于复配固化剂B1;土壤中Pb、Zn、Cd和As的固定作用主要发生在28 d以内,其后随着龄期增长修复土重金属浸出质量浓度变化较小,修复效果具有较好的长期稳定性;两种复配固化剂均能显著提高污染土壤pH值;与复配固化剂B1相比,复配固化剂B2能显著提高污染土强度,大幅降低固化体的可渗透性,综合固化稳定化效果更佳。Synthetic precipitation leaching procedure and pH testing of five types of industrial waste,waste biomass,and mineral material treated soils were carried out on artificially prepared high-concentration heavy metals co-contaminated soil.It was found that different binder raw materials have significant selectivity for the immobilization of heavy metals including Pb,Zn,Cd,and As.Besides,the production cost,environmental friendliness,and energy consumption of the binder raw materials were taken into account to screen the preferred raw materials that could offer better overall performance.Two new product-based binders,named B1 and B2,were then prepared by compounding the selected binder raw materials.The curing effect and long-term stability of the new binder,as well as the pH,unconfined compressive strength,and permeability coefficient of the cured soil were tested using a really high concentration of contaminated soil as the target.The results show that B1 and B2 have a satisfactory stabilization effect on four heavy metals,and the stabilization rates of heavy metals are higher than 80%at all dosage levels,which increases with increasing dosage levels.B1 was better than B2 for the stabilization of Pb,Zn,and Cd,while B2 was better than B1 for the stabilization of As.The stabilization of Pb,Zn,Cd,and As in the soil mainly occurred within 28 days,and the leached heavy metals concentrations from the treated soils reduced with curing time.In addition,both the two new binders treated soils have excellent long-term stability.Both B1 and B2 led to a significant increase in the pH of the contaminated soil.Compared with B1,B2 can significantly increase the strength of the co-contaminated soil and reduce the permeability of the solidified body,resulting in a better overall remediation performance.

关 键 词：环境工程学 污染土壤 修复材料 PH值 强度 

分 类 号：X53[环境科学与工程—环境工程]