凹凸棒石-双交联水凝胶微球钝化修复镉污染土壤研究
Passivation remediation of cadmium contaminated soil by attapulgite-double-crosslinked hydrogel microspheres
钟晓琴 1贺广喜 1马雪 1朱霞萍 1任维 2赵平2
作者信息
- 1. 成都理工大学材料与化学化工学院,四川成都 610059
- 2. 贵州省地质矿产勘查开发局一○五地质大队,贵州贵阳 550018
- 折叠
摘要
为研究凹凸棒石-双交联水凝胶微球(SA/PVA/ATP)对镉污染土壤钝化修复的效果,将SA/PVA/ATP添加到镉浓度为3.72 mg/kg的土壤中进行淹水培育,采用模拟酸雨、二乙烯三胺五乙酸(DTPA)和三乙醇胺(TEA)混合提取剂(DTPA提取剂)提取土壤有效态镉;采用欧共体标准局顺序提取方法(BCR)提取土壤中不同形态镉;讨论了SA/PVA/ATP添加量、土壤有效态镉和各形态镉的相关性;计算了钝化容量、修复效率和重金属风险评价指数,探究了 SA/PVA/ATP对土壤镉的钝化机理.结果显示,随着SA/PVA/ATP的增加,DTPA提取剂和酸雨提取的有效态镉含量分别从1.72 mg/kg和0.024 mg/kg下降到0.66 mg/kg和0.004 4 mg/kg;土壤中的弱酸可提取态镉和可还原态镉含量分别从1.40 mg/kg和0.81 mg/kg下降到1.01 mg/kg和0.41 mg/kg,而可氧化态镉和残渣态镉含量分别从0.86 mg/kg和0.63 mg/kg增加到0.95 mg/kg和1.27 mg/kg.材料添加量与土壤中有效态镉、弱酸提取态镉和可还原态镉含量呈极显著负相关,与可氧化态镉和残渣态镉含量呈极显著正相关;SA/PVA/ATP添加量为2.0％时,钝化容量最大为19.15 mg/kg,修复效率最高为34.89％,土壤环境由高风险降至中风险.SA/PVA/ATP将土壤中镉的弱酸提取态和可还原态逐渐转化为可氧化态和残渣态,降低了镉的生物有效性,实现了镉污染土壤的钝化修复.
Abstract
In order to study the passivation remediation effect of attapulgite-double-crosslinked hydrogel micro-spheres(SA/PVA/ATP)on cadmium contaminated soil,SA/PVA/ATP was added to cadmium contaminated soil with concentration of 3.72 mg/kg for flooding cultivation,using simulated acid rain,mixed extractant of diethyle-netriamine pentaacetic acid(DTPA)and triethanolamine(TEA)(DTPA extractant)to extract available cadmium,and using sequential extraction method of the European Community Bureau of Standards(BCR)to extract different forms of cadmium in soil.The correlation between SA/PVA/ATP addition,available cadmium and various forms of cadmium in soil was discussed.The passivation capacity,remediation efficiency and heavy metal risk assessment index were calculated,and the passivation mechanism of SA/PVA/ATP on soil cadmium was explored.The results show that with the increase of the amount of SA/PVA/ATP,the available cadmium content of DTPA extractant and acid rain extraction decrease significantly from 1.72 mg/kg and 0.024 mg/kg to 0.66 mg/kg and 0.004 4 mg/kg respectively,the content of weak acid extractable and reducible cadmium in soil decrease significantly from 1.40 mg/kg and 0.81 mg/kg to 1.01 mg/kg and 0.41 mg/kg,respectively,while the content of oxidizable and residual cadmium increase significantly from 0.86 mg/kg and 0.63 mg/kg to 0.95 mg/kg and 1.27 mg/kg,respectively.The addition of material has a significant negative correlation with available cadmium,weakly acid extractable cad-mium and reducible cadmium,while a significant positive correlation with oxidizable cadmium and residual cadmi-um.When the addition of SA/PVA/ATP is 2.0％,the maximum passivation capacity is 19.15 mg/kg,the maxi-mum remediation efficiency is 34.89％,and the soil environment fall from high risk to medium risk.SA/PVA/ATP can reduce the bioavailability of cadmium and realize the passivation remediation of cadmium contaminated soil through transforming the weak acid extracted and reducible forms into oxidizable and residual forms in soil.
关键词
镉/土壤/钝化修复/凹凸棒石-双交联水凝胶/形态转化Key words
cadmium/soil/passivation remediation/attapulgite-double-crosslinked hydrogel microspheres/form transformation引用本文复制引用
基金项目
国家自然科学基金(42267009)
贵州省地矿局科技项目(黔地矿科合[2019]1号)
出版年
2024
国家科技期刊平台
NSTL
万方数据