原位热活化过硫酸盐降解VOCs的温度模拟与试验研究  

Temperature simulation and experimental study on degradation of VOCs by in situ thermal activated persulfate

作　　者：林匡飞[1] 张雨 张猛 王琪 刘冠宏 LIN Kuang-fei;ZHANG Yu;ZHANG Meng;WANG Qi;LIU Guan-hong(School of Resource and Environmental Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学资源与环境工程学院,上海200237

出　　处：《安全与环境学报》2022年第1期420-426,共7页Journal of Safety and Environment

基　　金：国家重点研发计划项目(2018YFC1800705);上海市环保科研项目(沪环科[2019]第3号);国家自然科学基金青年基金项目(41907110)。

摘　　要：为研究热活化过硫酸盐氧化技术的原位应用,通过构建热传导模型模拟土壤温度场,考察土柱内部不同位置、不同温度、不同过硫酸钠投加量条件下1,1,2-三氯乙烷(1,1,2-TCA)质量浓度的时空变化,以建立土壤温度场与过硫酸盐降解效率的对应关系。结果表明:原位热传导模型可精准预测土柱内土壤温度场变化;热活化过硫酸钠显著提高了1,1,2-TCA去除效果(0.5 h内去除率最大从3.8%提高至94.4%);过硫酸钠降解1,1,2-TCA效率随着温度升高而升高,其中最佳活化温度范围为60~70℃,温度超过85℃时对1,1,2-TCA降解有抑制作用;1,1,2-TCA在土柱中的质量浓度分布随温度场变化而变化。To simulate the in-situ application of thermally activated persulfate(PS)oxidation technology in soil remediation,a thermal conduction model(TCM)was constructed to fit the temperature field of the remediated soil.The spatial concentration distribution of 1,1,2-trichloroethane(1,1,2-TCA)was determined at sampling sites with different soil temperatures and PS dosages and a quantitative congruent relationship was established between the soil temperatures and the degradation efficiency of PS.To simulate the actual heating process in the remediate soil,the TCM was expressed by onedimensional polar coordinates.The first and third boundary conditions were adopted in TCM,and Newton's cooling law was taken into account.Soil samples obtained at different locations,temperatures,and dosages of PS were detected by Purge and trap gas chromatography.The research results indicated that the coefficient of heat conductivity coefficient(k)and coefficient of convection heat transfer(H)of the experimental soil can be simulated with measured temperature data,and the soil temperature field changes in the column can be predicted accurately by TCM.With increasing the height of the measured position,the value of H increases while the k value decreases,when the heat dissipation process at the top of the soil column is taken into account.Besides,k value is also affected by soil salinity changes induced by different doses of PS.The removal efficiency of 1,1,2-TCA is significantly increased by thermally activated PS(from 3.8%to 94.4%in 0.5 h).The degradation efficiency of PS increases with increasing the soil temperature,and the PS can be activated efficiently when the soil temperature is higher than 30℃.The optimal activation temperature of PS in the soil is in the range of 60-70℃,and the degradation of 1,1,2-TCA is inhibited when the soil temperature is higher than 85℃.The spatial concentration distribution of 1,1,2-TCA varied with the temperature field in the remediated soil.

关 键 词：环境工程学 原位热传导 温度场模拟 过硫酸钠 热活化 1 1 2-三氯乙烷 

分 类 号：X53[环境科学与工程—环境工程]