生态与农村环境学报 ›› 2018, Vol. 34 ›› Issue (2): 169-176.doi: 10.11934/j.issn.1673-4831.2018.02.010

• 污染控制与修复 • 上一篇    下一篇

FeCl3-柠檬酸对低浓度As3+污染土壤的淋洗特性

邓天天, 马培, 李晗晟, 郭枫, 吴烨   

  1. 河南工程学院资源与环境学院/煤化工资源综合利用与污染治理河南省工程实验室, 河南 郑州 451191
  • 收稿日期:2017-05-15 出版日期:2018-02-25 发布日期:2018-02-09
  • 作者简介:邓天天(1987-),女,河南洛阳人,讲师,博士,主要从事地下水及土壤重金属污染治理。E-mail:280233394@qq.com
  • 基金资助:

    河南工程学院博士基金(D2016013);2017河南省科技计划(2017820)

Characteristics of FeCl3-Citric Acid Leaching Arsenic From Soil Low in As3+ Contamination Level

DENG Tian-tian, MA Pei, LI Han-sheng, GUO Feng, WU Ye   

  1. School of Environmental Studies/Henan Engineering Laboratory of Pollution Control and Coal Chemical Resources Comprehensive Utilization, Henan University of Engineering, Zhengzhou 451191, China
  • Received:2017-05-15 Online:2018-02-25 Published:2018-02-09

摘要:

以人工采集制备的w=100 mg·kg-1砷污染土壤为研究对象,采用超声溶解的方式获得FeCl3-柠檬酸复合淋洗剂,对不同淋洗剂配比、pH值、温度和常见共存阴阳离子(Ca2+、Al3+、SO42-、PO43-)对砷污染土壤淋洗特性的影响和机理进行研究。结果表明,在相同的土液比(1:10)条件下,m(FeCl3):m(柠檬酸)=3:1时对土壤中As的淋洗效果最佳,复合淋洗剂的淋洗效果优于单一淋洗剂。pH值和一定范围内温度的升高均有助于增加淋洗量。在pH值为7、8、9、10和温度为25、35、45℃时,淋洗动力学均符合Elovich方程,说明FeCl3-柠檬酸对As3+污染土壤的淋洗属于非均相的扩散过程。不同浓度(0.01~0.2 mol·L-1)的Ca2+、Al3+、SO42-、PO43-对淋洗效果均有一定影响。除SO42-外,其他共存离子浓度越大,淋洗效果越好。

关键词: FeCl3-柠檬酸, As3+, 污染土壤, 淋洗特性

Abstract:

As contaminated-soil samples were prepared artificially with As concentration being 100 mg·kg-1 for the study on the use of FeCl3-citric acid, a compound leachate prepared by means of ultrasonic dissolution, to leach As from As contaminated soils and effects of ratio, pH, temperature of the leachate and commonly coexisting anions or cations (Ca2+, Al3+, SO42- and PO43-) on leaching characteristics and their mechanisms. Results show that in solutions the same in soil-to-liquid ratio (1:10), the compound leachate maximized its effect of leaching As from As-contaminated soils when its m(FeCl3):m(citric acid) was 3:1 and was better than simple leachates in leaching effect. Rising pH and temperature within a certain range contributed to leaching. In solutions with pH being 7, 8, 9 or 10 and temperature at 25, 35 or 45℃, the leaching kinetics could be better described with the Elovich equation, which indicates that the leaching of As with FeCl3-citric acid from As3+ contaminated soil is a heterogeneous diffusion process. The coexisting ions, such as Ca2+, Al3+, SO42- and PO43-, 0.01~0.2 mol·L-1 in concentration also had certain impacts on leaching of As. The higher the concentrations of the other coexisting ions, except for SO42-, the better the leaching effect. The compound leachate is expected to have a bright prospect for its application thanks to its low cost and wide availability.

Key words: FeCl3-citric acid, contaminated soil, As3+, leaching characteristics

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