土壤主要组分对多氯联苯吸附及共存Cu^(2+)的影响  

Adsorption of PCBs onto main components in soil and effect of coexistent Cu^(2+)

作　　者：陈涛[1] 孙成勋[1] 杨晓瑛[1] 朱宝余[1] 

机构地区：[1]吉林省电力科学研究院,吉林长春130021

出　　处：《中国矿业大学学报》2012年第5期821-826,共6页Journal of China University of Mining & Technology

基　　金：国家高技术研究发展计划(863)项目(2007AA06A410)

摘　　要：采用选择性萃取分离方法对土壤中的主要化学组分锰氧化物、铁氧化物和有机质进行分离,在此基础上,采用批量平衡法研究了25℃下土壤原样、去锰氧化物样品、去铁氧化物样品和去有机质样品对多氯联苯(PCBs)的吸附热力学特征和吸附机理,以及不同含量的共存重金属Cu2+对多氯联苯吸附规律的影响.结果表明:Langmuir和Freundlich吸附模型均可较好地描述多氯联苯在土壤各级样品上的吸附热力学过程.通过比较Langmuir和Freundlich模型所获得的拟合参数可知,土壤各级样品对多氯联苯的吸附规律为:去锰氧化物样品>去铁氧化物样品>土壤原样>去有机质样品.土壤中的有机质和铁氧化物对多氯联苯吸附起主要作用,锰氧化物则抑制多氯联苯的吸附.吸附体系中的共存重金属Cu2+与多氯联苯产生了竞争吸附作用,抑制了土壤各级样品对多氯联苯的吸附,二者之间的竞争吸附作用主要可能发生在铁氧化物和有机质中.The selective extraction technique was employed to separate main chemical compo- nents Mn oxides, Fe oxides and organic matter in soil, based on thatthe thermodynamic char- acteristics and mechanisms of polychlorinated biphenyls （PCBs） adsorption onto the raw soil sample, Mn-oxides-removed soil sample, Fe-oxides-removed soil sample and organic-matter-re- moved soil sample at 25 ~C, and the effect of coexistent Cu2＋ in various concentrations were in- vestigated by the batch equilibration. The results show that the thermodynamic processes of PCBs adsorption can be described well by Langmuir and Freundlich adsorption equations. PCBs adsorption by the different soil samples follows this order Mn-oxides-removed soil sample^Fe- oxides-removed soil sample^raw soil sample^organic-matter-removed soil sample by compa- ring the constants from Langmuir and Freundlich adsorption equations. PCBs can be adsorbed mainly by the organic matter and Fe oxides of soil, however, inhibited by Mn oxides. There is a competitive adsorption between Cu2＋ and PCBs in the combined adsorption system, there- fore, PCBs adsorption onto the different soil samples are inhibited, and the competitive adsorp- tion maybe mainly exist in the organic matter and Fe oxides of soil.

关 键 词：多氯联苯(PCBs) 吸附 土壤 CU2+ 

分 类 号：X132[环境科学与工程—环境科学]