生态与农村环境学报2018，Vol.34Issue(1)：87-95,9.DOI:10.11934/j.issn.1673-4831.2018.01.011
以设计精准修复方案为目标的土壤重金属形态分布研究
Distribution of Heavy Metals by Form for Precise Remediation of Polluted Farmland Soil
摘要
Abstract
In-situ immobilization/stabilization of heavy metals in farmland soil is a soil remediation technology through a-mending the soil with certain chemical agents to reduce activity of the pollutants, inhibit their transport from soil to crops and hence mitigate their risks to crops. A total of 32 soil samples were collected from heavy metal polluted croplands in Henan Province for analysis of Cd, Pb, As, Cu, Zn, Ni and Cr for their totals and various fractions, i. e., weak-acid ex-tractable, reducible, oxidizable and residue, using the BCR sequential extraction method, and then a precise soil remedia-tion program formed. Results show that the concentration of Cd, Pb, As, Cu, Zn, Ni and Cr in the soil was on average 1. 90, 144. 91, 7. 33, 32. 24, 91. 40, 28. 80 and 19. 76 mg·kg-1 , respectively. Among them, Cd and Pb concentration in the soil was far beyond the criteria of the"Standard for Environmental Quality Evaluation Standards of Farmlands Producing Edible Agricultural Produce ( HJ/T 332-2006)" reaching 3. 17 and 1. 81 times as high, respectively. The analysis using the BCR sequential extraction method shows that weak acid extractable Cd was relatively high in percentage of the to-tal, reaching up to 24. 06％;Pb existed in the soil mainly in reducible form, which accounted for 80. 35％ of the total in the soil, while the other 5 elements existed mainly in residual form. Regression analysis models were established based on contents of the weak acid extractables and their respective total of the heavy metal elements in the soil, indicating that the former varied with the latter exhibiting positive linear relationships between the two. According to the differences weak acid extractable Cd and Pb and their respective total in spatial distribution, the study area was partitioned. The partitioning by total Cd differed somewhat from that by weak acid extractable Cd, while the partitioning by weak acid extractable Cd was quite similar to that by weak acid extractable Pb, which may serve as a basis for formulation of a precise soil remediation program. In the end, levels and risks of the heavy metal pollution of the soil in view of the total and the content of available form of heavy metals, separately. Hakanson Potential Ecological Risk Assessment shows that Cd in the soil posed a strong potential ecological risk, but Cd in the soil was rated as moderate in risk according to the Risk Assessment Code ( RAC) . The difference between the two evaluations suggests that it is essential to take into account results of all various evaluation methods to program remediation of heavy metals polluted soils. This study may have laid down a foundation for evaluation and remediation of heavy metal polluted soils.关键词
农田土壤/原位稳定化/重金属形态/分区处理/精准修复/风险评价Key words
farmland soil/in-situ stabilization/fraction of heavy metal/partitioning of the study area/precise remedia-tion/risk evaluation分类
资源环境引用本文复制引用
王佳佳,李翔,罗楠,何跃,刘永兵,卢一富,苗向前,吕利光..以设计精准修复方案为目标的土壤重金属形态分布研究[J].生态与农村环境学报,2018,34(1):87-95,9.基金项目
国家重金属污染防治专项(JGZJ-工-2015152-02) （JGZJ-工-2015152-02）
北京市科学技术研究院财政专项(2016-A-30) （2016-A-30）
中央级公益性科研院所基本科研业务专项(2017年) （2017年）
中科院盱眙凹土应用技术研发与产业化中心开放性课题资助项目(201506) （201506）
