摘要
以邻二甲苯为石油烃类污染物代表,以污染土壤质量的减少量以及冷凝液质量的增加量表征土壤污染物的平均脱附效率,研究了微波-超声波耦合热源处理石油烃类污染土壤的脱附规律。结果表明,在超声波功率恒定(800 W)情况下,增大微波功率(从200 W增到400 W),能显著提升装置内反应温度(从128.3℃增到270.1℃),显示了微波较强的热效应;在微波功率恒定(350 W)情况下,增大超声波功率(从600 W增到1 400 W),对装置升温效果影响不明显(从169.4℃增加到187.9℃),表明了超声波较弱的热效应。超声波/微波耦合热源修复壤土的最优工艺参数为土水比20∶1、超声波功率800 W、微波功率350 W、辐照10 min,相应的最高污染物平均脱附率为77.28%,处理效果优于单热源条件。对于不同的土壤粒径及有机质含量,不同类型土壤的平均脱附率排序为砂土(88.36%)>壤土(64.29%)>黏土(52.61%);综合考虑土壤介电损耗因子、土壤比热容、土壤通透性影响的结果,土水比最优值设为10∶1;综合考虑土壤颗粒单层吸附/多层吸附作用的结果,土壤污染物浓度最优值为8%(砂土)、4%(壤土、黏土)。
Petroleum hydrocarbon contaminated soil was treated by microwave-ultrasonic coupling desorption,with 1,2-dimethylbenzene as a kind of representative pollutant.The average desorption efficiencies were characterized by the reduction of soil quality and the increase of condensate quality.The results showed that the reaction temperatures increased significantly from 128.3℃to 270.1℃when microwave power increased from200 W to 400 W at a constant ultrasonic power of 800 W,indicating the strong thermal effect derived from microwave.The heating temperatures fluctuated between 169.4℃and 187.9℃when ultrasonic powers increased from 600 W to 1 400 W at a constant microwave power of 350 W,indicating the weak thermal effect derived from ultrasonic waves.The optimal process parameters of loam soil remediation with the coupled ultrasonic/microwave were as follows:soil-water ratio of 20:1,ultrasonic power of 800 W,microwave power of350 W,10 min irradiation,and the corresponding highest average desorption rate was 77.28%,which was better than that with single heat source.In view of different soil particle size and organic matter content,the average desorption rates for different types of soil were ranked as sandy soil(88.36%)>loam soil(64.29%)>clay soil(52.61%).The optimal soil-water ratio was 10∶1,which was a comprehensive effecting result of the soil dielectric loss factor,specific heat capacity and permeability.The optimal concentration of soil pollutants was8%for sandy soil,and 4%for loam soil and clay soil,which were the comprehensive results of singlelayer/multi-layer adsorption of soil particles.
作者
桑义敏
艾贤军
马绍芳
王亚飞
朱玲
余望
何燎
杨康
SANG Yimin;AI Xianjun;MA Shaofang;WANG Yafei;ZHU Ling;YU Wang;HE Liao;YANG Kang(Department of Environmental Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2019年第10期2311-2319,共9页
Chinese Journal of Environmental Engineering
基金
国家重点研发计划重点专项(2018YFC1802100)
关键词
石油烃
土壤修复
热脱附
微波
超声
petroleum hydrocarbons
soil remediation
thermal desorption
microwave
ultrasonic
