复合淋洗剂柱淋洗法修复工业废弃地铬污染土壤  

Column leaching of Cr from industrial discarded land soils using composite leaching agents

作　　者：孙玉焕[1] 宋淑敏[1] 张亮[1] 

机构地区：[1]青岛科技大学环境与安全工程学院,山东青岛266042

出　　处：《环境污染与防治》2017年第2期191-196,201,共7页Environmental Pollution & Control

基　　金：山东省自然科学基金资助项目(No.ZR2013DQ002);青岛市民生科技计划项目(No.14-2-3-70-nsh)

摘　　要：为了更好地修复铬污染土壤,以盐酸、柠檬酸为初始淋洗剂,配合去离子水、石灰水、氯化钙、碳酸钠和磷酸钠,制定了20种复合淋洗剂的淋洗方案对某工业废弃地铬污染土壤进行柱淋洗实验,研究复合淋洗剂对土壤pH、总铬和Cr(Ⅵ)去除效果及对各形态铬变化的影响。结果表明:(1)各淋洗方案对土壤总铬和Cr(Ⅵ)的去除量分别为197.4~1 671.6、113.2~316.8mg/kg,其中初始淋洗剂盐酸、柠檬酸结合使用对总铬有较好的去除效果。(2)石灰水和磷酸钠可以将淋洗后的土壤pH调至接近中性并固定尚未淋洗出的Cr(Ⅵ)。(3)当0.2mol/L柠檬酸、0.1mol/L盐酸、0.2mol/L盐酸、1%(质量分数)石灰水用量分别为2、2、1、2mL/g进行淋洗时,土壤pH为7.37,总铬和Cr(Ⅵ)去除量分别为1 659.8、316.8mg/kg,去除率分别为34.6%、72.7%,水溶态铬、可交换态铬和碳酸盐态铬已被大量淋出,有机态铬与残渣态铬占比较其他淋洗方案低,为最佳淋洗方案。In order to repair the Cr contaminated soil in a better way,hydrochloric acid and citric acid were used as the initial leachants. Deionized water, whitewash, calcium chloride, sodium carbonate and sodium phosphate were added to develop 20 different column leaching programs, and the removal rate of total Cr and Cr（ Ⅵ ）, Cr fractions and pH were analyzed in this experiment. The results indicated that： （1） the total Cr removal quanities in all programs were between 197.4 mg/kg and 1 671.6 mg/kg, and Cr（VI） removal quanities were from 113.2 mg/kg to 316.8 mg/kg, and the combined use of hydrochloric acid and citric acid had better removal effect on total chromium. （2） Unleaehed Cr（Ⅵ） could be fixed by witewater and sodium phosphate,which could also adjust pH of leached soil to neutral. （3） When the dosage of 0.2 mol/L citric acid,0.1 mol/L hydrochloric acid,0.2 mol/L hydrochloric acid and 1% （mass ratio） whitewash were 2,2,1 and 2 mL/g, and the pH of soil was 7.37,the total Cr removal quanity was 1 659.8 mg/kg with 34.6% removal rate,and Cr（Ⅵ） removal quanity was 316.8 mg/kg with 72.7% removal rate. The results also showed that the most Cr of water soluble,exchangeable and carbonate bound were extracted,and the percentage of organic bound and residual were lower than other programs.

关 键 词：铬 污染土壤 柱淋洗 修复技术 工业废弃地 

分 类 号：X53[环境科学与工程—环境工程]