摘要
针对土壤铬污染严重的问题,通过自行设置的电动去除装置,研究电动法在不同电压、电解液种类和浓度的条件下对铬去除效果的影响。结果显示:电动法能够有效去除土壤中的重金属铬,并且土壤中铬(Ⅵ)的迁移受电压的影响较大,当电压从10 V增大至40 V时,铬(Ⅵ)的去除率提高了12.25百分点。电解液中加入0.05 mol/L十二烷基苯磺酸钠(Sodium Dodecyl Benzene Sulfonate, SDBS)后铬(总)的去除率提高了5.94百分点,但增大SDBS浓度对提升铬的去除率没有明显效果。柠檬酸(Citric Acid, CA)可显著促进铬的迁移,柠檬酸浓度越大,铬的去除效率越高。在电解液中加入0.15 mol/L柠檬酸后铬(总)的去除率增长幅度达到最大,提高了18.03百分点,铬(Ⅵ)的去除率达到了93.4%,铬(总)的去除率达到了74.96%。其中,弱酸提取态和可还原态铬的去除量占铬(总)去除量的95%左右,CA能够促进残渣态铬向弱酸提取态转换并促进铬的迁移,使各形态铬的残余量均有所下降,进而使铬污染土壤的毒性大幅降低。经电动去除后,土壤表面呈现出针状、絮状或颗粒状,并出现了大量细小的孔隙,结构变得相对松散。
To solve the problem of soil pollution,the removal behaviors of chromium from contaminated soil were studied via the electrokinetic method using the self-set electrokinetic device,considering of the influencing factors such as voltage,electrolyte type,and concentration.The results show that the electrokinetic method can effectively remove heavy metal chromium in soil,and the migration of chromium(Ⅵ)in soil is greatly affected by voltage.When the voltage increases from 10 V to 40 V,the removal rate of chromium(Ⅵ)increases by 12.25%.However,the removal rate of chromium(total)slightly increases only by 3.72%.After adding 0.05 mol/L Sodium Dodecyl Benzene Sulfonate(SDBS)to the electrolyte,the removal rate of chromium(total)increases by 5.94%,and the removal rate of chromium(Ⅵ)increases by 4.77%after adding 0.15 mol/L SDBS,indicating that SDBS has no significant effect on the electromigration of chromium from contaminated soil.The Citric Acid(CA)can efficiently enhance the electromigration of chromium,and increasing the concentration of CA could improve the removal rate of chromium.When 0.15 mol/L citric acid is added to the electrolyte,the removal rate of chromium(total)increases by 18.03%,the removal rate of chromium(Ⅵ)reaches 93.4%,and the removal rate of chromium(total)reaches 74.96%.The removal amount of weak acid extraction and reducible chromium accounts for about 95%of the total chromium removal amount.Citric acid can promote the conversion of residual chromium to a weak acid extraction state and promote the migration of chromium,so that the residual amount of chromium in various forms is reduced,and the toxicity of chromium-contaminated soil is greatly reduced.After electrokinetic removal,the surface of the soil appeared needle-like,flocculent,or granular.A large number of small pores could also be observed,and the structure became relatively loose.
作者
王艳
张李奕岚
朱鹏
王恒宇
WANG Yan;ZHANG Liyilan;ZHU Peng;WANG Hengyu(School of Civil&Environmental Engineering and Geography Science,Ningbo University,Ningbo 315211,Zhejiang,China;School of Civil Engineering and Architecture,Ningbo Tech University,Ningbo 315100,Zhejiang,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2024年第8期3251-3259,共9页
Journal of Safety and Environment
基金
国家自然科学基金项目(52378372)。
关键词
环境工程学
电动力学
铬
污染土壤
environmental engineering
electrokinetics
chromium
contaminated soil
