重金属污染土壤经EDTA+CA复合淋洗后营养元素流失的研究  

Study on Nutrient Element Loss in Heavy Metal Contaminated the Soil Soil after EDTA and CA Compound Washing Remediation

作　　者：张妮 黄秋语 张哲 白婷婷 申小雨 Zhang Ni;Huang Qiuyu;Zhang Zhe;Bai Tingting;Shen Xiaoyu(Shanxi Provincial Transportation Environmental Protection Center Station(Co.,Ltd.),Taiyuan Shanxi 030000,China;Chengdu Comprehensive Rock and Mineral Testing Center of Sichuan Geological and Mineral Exploration and Development Bureau,Chengdu Sichuan 610081,China)

机构地区：[1]山西省交通环境保护中心站(有限公司),山西太原030000 [2]四川省地质矿产勘查开发局成都综合岩矿测试中心,四川成都610081

出　　处：《山西化工》2024年第7期268-271,共4页Shanxi Chemical Industry

摘　　要：在实际修复工作中,Na_(2)EDTA(乙二胺四乙酸二钠)和CA(柠檬酸)都是经济有效的淋洗剂。但在淋洗修复效果评估方面仅仅是以目标污染物的含量为标准,不能真实地反映淋洗后土壤的营养元素流失状况。本文以重金属(Zn、Pb、Cd)污染的农田土壤为研究对象,采用Na_(2)EDTA和CA复配淋洗剂的最佳条件对污染土壤进行淋洗实验,探究淋洗修复完成后营养元素的流失程度。结果表明,EDTA和CA复配淋洗剂作提取剂时,对5种矿质元素仍然有洗脱作用,洗脱率的顺序为Ca>Mn>Fe>K>Mg,分别为60.1%、44.8%、18.0%、14.5%、5.98%;同时土壤淋洗能够改变矿质元素的有效性,EDTA和CA浸提提高了土壤中Mg、Fe、Mn的有效性,降低了土壤中K、Ca的有效性。土壤淋洗也会导致土壤理化性质发生改变,其中土壤pH发生显著变化,从8.03下降到4.56,有机碳含量升高,全磷、有效磷、总氮以及碱性氮含量降低,损失率分别为57.8%、45.9%、25.6%、17.0%。In practice,Na2EDTA and CA are economical and effective leaching reagents.However,the evaluation of remediation result is just based on the concentration of the target pollutant,which cannot truly reflect the loss of nutrients.This paper focused on treating the heavy metal contaminated farmland soil.It took the best conditions of Na2EDTA and CA to carry out a series of experiments,to explore the loss-degree of nutrients in after-leaching soil.The results showed that the soil leaching technology can effectively remove Zn,Pb,Cd.At the same time,there are still elution effects on the five mineral elements.The elution rate was in the order of Ca>Mn>Fe>K>Mg,which was 60.1%,44.8%,18.0%,14.5%,and 5.98%,respectively.The soil leaching technology can the availability of mineral elements.The leaching of EDTA and CA increased the availability of Mg,Fe,and Mn and reduced the availability of K and Ca in the soil.The leaching and remediation technology also resulted in a significant change in pH from 8.03 down to 4.56.The content of nutrients in the soil showed a decreasing trend after leaching.The total phosphorus loss rate was the highest,followed by the available phosphorus.The loss of total nitrogen and basic nitrogen is minimal.The loss rates were 57.8%,45.9%,25.6%,and 17.0%,respectively.

关 键 词：重金属 土壤淋洗 营养元素流失 

分 类 号：X53[环境科学与工程—环境工程]