长江科学院院报 ›› 2019, Vol. 36 ›› Issue (9): 23-28.DOI: 10.11988/ckyyb.20180145

• 水资源与环境 • 上一篇    下一篇

农田土壤重金属Cd的环保淋洗剂筛选研究

胡园1,2,林莉1,2,胡艳平1,2,黎睿1,2   

  1. 1.长江科学院 流域水环境研究所,武汉 430010;
    2.长江科学院 流域水资源与生态环境科学湖北省重点试验室,武汉 430010
  • 收稿日期:2018-02-07 修回日期:2018-04-17 出版日期:2019-09-01 发布日期:2019-09-12
  • 通讯作者: 林 莉(1983-),女,湖北咸宁人,教授级高级工程师,博士,主要从事水环境治理研究。E-mail:artemis066@163.com
  • 作者简介:胡 园(1988-),女,湖北麻城人,助理工程师,主要从事土壤修复技术研究。E-mail:agilent1005@126.com通信作者:林 莉(1983-),女,湖北咸宁人,教授级高级工程师,博士,主要从事水环境治理研究。E-mail:artemis066@163.com
  • 基金资助:
    水利部公益性行业科研专项(201501019)

Selecting Ferric Chloride as an Environmental-friendly Washing Agent for Heavy Metal Cadmium in Farmland Soil

HU Yuan1,2, LIN Li1,2, HU Yan-ping1,2, LI Rui1,2   

  1. 1.Basin Water Environment Department, Yangtze River Scientific Research institute, Wuhan 430010, China;
    2.Hubei Provincial Laboratory of Basin Water Resources and Eco-environmental Sciences, Yangtze River Scientific Research institute, Wuhan 430010, China
  • Received:2018-02-07 Revised:2018-04-17 Online:2019-09-01 Published:2019-09-12

摘要: 土壤淋洗是一种有效修复重金属污染土壤的方法,而淋洗剂的选择是淋洗过程的关键因素,直接影响淋洗效率。研究了4种淋洗剂(乙酸、柠檬酸、CaCl2、FeCl3)对Cd轻度污染的农田土壤淋洗性能及影响因素。结果表明:淋洗效果依次为FeCl3>柠檬酸>乙酸>CaCl2;FeCl3的淋洗机理是Fe3+与土壤中的Cd2+离子交换,其水解出的H+可促进碳酸盐结合态Cd溶出,Cl-还可与Cd2+形成稳定的螯合物;经优化后的最佳的淋洗条件是固液比为1∶5,浸提时间为4 h,此时乙酸、柠檬酸、CaCl2和FeCl3的最大土壤Cd去除率分别为30.24%,24.62%,24.82%,81.90%;pH值对淋洗效果的影响较大,除CaCl2外,3种淋洗剂的淋洗效果都随pH值的升高而降低(pH值在2.5~5.0范围内),FeCl3的淋洗效果降低最为显著。研究成果可为Cd污染农田土壤修复提供技术支撑。

关键词: 农田土壤, 重金属镉污染, 土壤淋洗, FeCl3, 有机酸

Abstract: Soil washing is an effective approach for the remediation of heavy metal contaminated soil. Soil washing agent is a crucial factor which directly affects the efficiency of washing. We examined the performances of four washing agents, inclusive of acetic acid, citric acid, CaCl2, and FeCl3, in purifying farmland soil slightly contaminated by Cadmium (Cd) and the influential factors. We found that the effect of FeCl3 is the optimum, followed by citric acid, acetic acid, and CaCl2 in sequence.The H+ hydrolyzed from the exchange between Fe3+ from FeCl3 solution and Cd2+ from the soil stimulated the dissolution of carbonate bounded form of Cd; Cl- together with Cd2+ could also form a stable chelate. In optimized operation condition (solid-liquid ratio at 1∶5, and washing for 4 hours), the maximum removal rate of Cd was 30.24%, 24.62%,24.82%, and 81.90% by acetic acid, citric acid, CaCl2, and FeCl3, respectively. The pH value of soil had large impact on the washing effect. Apart from CaCl2,the washing effects of the other three washing agents all declined with the rising of pH value within 2.5-5.0, among which the washing effect of FeCl3 underwent the most severe decline.

Key words: farmland soil, cadmium contamination, soil washing, FeCl3, organic acids

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