加热气氛对柴油污染土壤低温热处理的影响  

Effects of Carrier Gas on Diesel-contaminated Soil Under Low Temperature Thermal Treatment

作　　者：李康 宋昕[1] 丁达 任家强 魏昌龙[1] 唐志文 王晴[1] LI Kang;SONG Xin;DING Da;REN Jiaqiang;WEI Changlong;TANG Zhiwen;WANG Qing(Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院土壤环境与污染修复重点实验室(南京土壤研究所),南京210008 [2]中国科学院大学,北京100049

出　　处：《土壤》2021年第2期336-342,共7页Soils

基　　金：国家自然科学基金青年科学基金项目(41701365);中国科学院科技服务网络计划(STS计划)项目(KFJ-STS-ZDTP-039);国家重点研发计划项目(2019YFC1805700)资助。

摘　　要：在N_(2)、CO_(2)、空气3种气氛条件下对柴油污染土壤进行250℃低温热处理,研究3种气氛对石油烃去除率、土壤碳/氮含量以及土壤中挥发/半挥发性有机污染物组分的影响。结果表明:在3种气氛条件下,柴油污染土壤中的石油烃总量去除率均超过98%,达到国家相关土壤质量环境标准。柴油污染土壤经过低温热处理后,污染物在土壤表层产生焦炭膜,使得热处理后的土壤保留较稳定的碳含量。土壤中的铵态氮和硝态氮受气氛影响较大,N2条件下低温热处理后土壤中铵态氮和硝态氮含量大幅增加,而空气和CO_(2)条件下相对减少。柴油污染土壤中的挥发性有机污染物,经3种气氛条件下低温热处理后,大部分均被去除,仅CO_(2)气氛下残余少量苯系物;柴油污染土壤在热处理后有少量萘、菲等低分子量多环芳烃生成,在250℃温度下可能有产生低分子量多环芳烃的风险。综上所述,低温热处理是修复柴油污染土壤高效、可行的方法。The effects of carrier gases,including nitrogen,air,and carbon dioxide,on diesel-contaminated soil were studied under the low temperature thermal treatment(LTTT).The removal rate of total petroleum hydrocarbons(TPHs),the contents of soil carbon,nitrogen,volatile organic contaminants(VOCs)and semi-volatile organic contaminants(SVOCs)were quantitatively investigated after LTTT at 250℃.The results showed that the removal rates of TPHs exceeded 98%under all three carrier gases,meeting the relevant national standards of soil quality.Carbon content remained relatively stable,primarily due to the impact of a coke film formed on soil surface during LTTT.The contents of ammonium nitrogen and nitrate nitrogen in the soil increased significantly after LTTT under nitrogen gas flow,but decreased under the gas flow of air and carbon dioxide.VOCs in diesel-contaminated soil were mostly removed under all three carrier gas conditions after LTTT,except that a small amount of benzene left under the carbon dioxide gas flow condition.However,small amounts of low-molecular weight PAHs,such as naphthalene and phenanthrene,were generated.In summary,LTTT is an efficient and feasible method to remediate diesel-contaminated soil.

关 键 词：柴油污染土壤 低温热处理 加热气氛 

分 类 号：X53[环境科学与工程—环境工程]