氧化钙活化过硫酸盐修复重金属-有机物复合污染土壤  

Remediation of heavy metal-organic compound polluted soil by calcium oxide activated persulfate oxidation

作　　者：程爱华[1] 程岩 李晓军[1] CHENG Ai-hua;CHENG Yan;LI Xiao-jun(College of Geology and Environment,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054

出　　处：《应用化工》2024年第2期322-326,共5页Applied Chemical Industry

基　　金：陕西省教育厅服务地方专项科学研究计划(20JC026)。

摘　　要：采用氧化钙活化过硫酸盐氧化法修复重金属-有机物复合污染土壤,考察了过硫酸钠投加量、过硫酸钠与氧化钙投加比、水土比等对修复效果的影响,探讨了机理。结果表明,在过硫酸钠投加量2.5 mmol/g,氧化钙与过硫酸钠投加比2∶5,水土比3∶1的条件下,汞、砷的钝化率分别为81%和83%,存在形态由弱酸提取态转化为更为稳定的残渣态,氯仿、苯、总石油烃和1,2,3-三氯丙烷的去除率分别为99%,98%,82%,80%。氧化钙一方面,催化过硫酸盐,产生硫酸根自由基和羟基自由基氧化重金属、降解有机污染物。另一方面,通过物理固封和吸附、络合、沉淀作用钝化汞、砷。研究为重金属-有机物复合污染土壤修复技术的实际应用奠定基础。The calcium oxide activated persulfate oxidation method was studied to remediate heavy metal-organic compound polluted soil.Influence of sodium persulfate dosage,ratio of sodium persulfate to calcium oxide,soil and water ratio on the restoration effect were investigated,and the mechanism was discussed.The result showed that the dosage of sodium persulfate was 2.5 mmol/g,the dosage ratio of sodium persulfate and calcium oxide was 2∶5,and the water-soil ratio was 3∶1,the passivation rate of mercury and arsenic were 81%and 83%,and the existing forms of mercury and arsenic were converted from weak acid extraction state to more stable residue state,and the removal rate of chloroform,benzene,total petroleum hydrocarbons and 1,2,3-trichloropropane reached 99%,98%,82%and 80%.On one hand,calcium oxide catalyzes persulfate to generate sulfate radicals and hydroxyl radicals to oxidize heavy metals and degrade organic substances.On the other hand,mercury and arsenic are passivated through physical sealing and adsorption,complexation and precipitation.The study lays a foundation to the practical application of heavy metal-organic compound contaminated soil remediation technology.

关 键 词：土壤修复 重金属-有机物复合污染 氧化钙 过硫酸盐 

分 类 号：TQ03[化学工程] X53[环境科学与工程—环境工程]