肯尼亚水稻土和甘蔗地土壤中14C-六氯苯和14C-滴滴涕的自然消解  

Natural Attenuation of ^(14)C-HCB and ^(14)C-DDT in Kenya Paddy Soil and Sugarcane Field Soil

作　　者：金鑫[1,3,4] Fredrick Orori Kengara 王芳[1] 谷成刚[1] 杨兴伦[1] Ulrike Dorfler Reiner Schroll Jean Charles Munch 蒋新[1,4] JIN Xin Fredrick Orori Kengara WANG Fang GU Chenggang YANG Xinglun Ulrike Dorfler Reiner Schroll Jean Charles Munch JIANG Xin(Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China Department of Chemistry, Maseno University, Maseno 40105, Kenya Research Unit Microbe-Plant Interactions, Helmholtz ZentrumMiinchen, Munich 85764, Germany 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(中国科学院南京土壤研究所),南京210008 [2]马赛诺大学化学系,肯尼亚马赛诺40105 [3]亥姆霍兹慕尼黑研究中心微生物-植物交互作用研究组,德国慕尼黑85764 [4]中国科学院大学,北京100049

出　　处：《土壤学报》2017年第1期108-117,共10页Acta Pedologica Sinica

基　　金：国家重点基础研究发展计划(973计划)(2014CB441105);江苏省杰出青年基金项目(BK20150050);国家自然科学基金项目(21277148,21377138和41271327)资助~~

摘　　要：氯代持久性有机污染物的农田土壤污染呈现污染浓度低、面积大、新源污染不断输入的特点。农田土壤本身微生物种类丰富,对氯代有机污染物具有较大的降解潜力和未知性。本试验以典型高氯代和低氯代持久性有机污染物——六氯苯(HCB)和滴滴涕(DDT)为研究对象,结合^(14)C同位素示踪技术,研究HCB和DDT在热带水稻土和甘蔗地土壤的矿化现象,同时监测HCB和DDT在两种土壤中的挥发、降解产物以及结合残留。结果表明,经84 d好氧培养,HCB和DDT在两种土壤中的矿化量分别仅为0.14%和3%,低氯代有机污染物DDT的矿化速率显著高于高氯代有机污染物HCB。然而,两种土壤对HCB或DDT的矿化没有显著性差异。HCB或DDT在水稻土中的挥发量略微高于甘蔗地土壤,两种土壤中HCB和DDT的挥发量在0.1%~0.6%之间,表明挥发不是其主要的环境过程。在DDT污染水稻土和甘蔗地土壤中添加1.25%的堆肥增加了DDT在土壤中的矿化与结合残留,减少了DDT的挥发。本研究结果表明土壤在好氧条件下对氯代持久性有机污染物的自然消解能力非常弱,而有机肥的使用有助于土壤中持久性氯代有机污染物的矿化消除。Contamination of farmland soils with persistent organic pollutants （POPs） is still a problem of environmental concerns. Take hexachlorobenzene （HCB） and 1,1,1-trichloro-2,2-bis-4-chlorophenyl ethane （DDT） for example, pollution of farmland soils is generally characterized by being low in concentration and vast in area, and new pollutants flow in unceasingly from non-point sources. Farmland soils are rich in microorganisms, which potentially play a significant role in degrading such POPs. In this study, HCB and DDT were selected as representative of highly chlorinated and low chlorinated POPs, respectively, and soils were collected from a years-long paddy field and a years-long sugarcane field for use to study potentials of the soils naturally attenuating HCB and DDT. 14C-labeled HCB and 14C-labeled DDT were used for tracing mineralization, volatilization, metabolites, and bound residues to overcome the shortage of the traditional methodsfor studying the degradation of compounds. Traditional methods merely monitor the concentrations of the mother compound and/or the metabolites which may be sheltered in soil matrix via adsorption, and result in overestimating of the degradation extent. 14C-HCB and 14C-DDT were spiked respectively into the paddy soil and the sugarcane field soil, then incubated aerobically under the optimal water content （63% for paddy soil, 35% for sugarcane field soil） in an attempt to get the highest mineralization rate. Both the 14CO2 and the 14C-volatiles were trapped by specific liquid in a closed systemand measured with a scintillation counter. 14CO2 production corresponds to mineralization degree of the compounds. After 84 days of incubation, only 0.14% of 14C-HCB and 3% of 14C-DDT were mineralized. ASE extraction showed that penta-chlorobenzene was the only detected metabolites of HCB. DDD, DDE and DDMU were found to be the main metabolites of DDT. In the paddy soil samples, DDD was relatively higher in concentration,whereas in the sugarcane field soil samples DDE was. The

关 键 词：持久性有机污染物 堆肥 矿化 挥发 结合残留 

分 类 号：X53[环境科学与工程—环境工程]