机物料中溶解性有机质对土壤吸附除草剂的抑制作用  

The inhibit effects of dissolved organic matter extracted from organic materials on herbicide sorption in soil

作　　者：唐东民[1] 伍钧[1] 陈华林[2] 周江敏[2] 祝亮[1] 

机构地区：[1]四川农业大学资源与环境学院,四川雅安625014 [2]温州大学生命与环境科学学院,浙江温州325027

出　　处：《生态环境》2008年第2期589-592,共4页Ecology and Environmnet

基　　金：国家自然科学基金项目(40501065)

摘　　要：溶解性有机质(DOM)是陆地及水生生态系统中十分活跃的组分,对有机污染物质的环境行为(如毒性、迁移转化及生物可降解性等)有着重要的影响,而施用有机物料会释放大量的DOM。采用批量平衡法研究了水稻秸秆腐解产生的溶解性有机质对苄嘧磺隆(BSM)在土壤中吸附行为的抑制作用。结果表明,线性方程能很好地描述BSM在土壤中的吸附行为;添加DOM降低了BSM在土壤中的分配系数即logKd值,其logKd值与对照(不加DOM)间存在极显著差异(P<0.01),秸秆腐解时间越长,logKd值越小;亲水组分和疏水组分在DOM抑制土壤吸附BSM中起着不同的作用;BSM在土壤上的吸附自由能小于40kJ·mol-1,推测BSM在土壤上主要以物理吸附为主,吸附机理可能有范德华力、疏水键、氢键和偶极键力,不存在化学键吸附作用。Dissolved organic matter （DOM） is a very important component in terrestrial and aquatic ecosystems. It can affect the toxicity, transformation, fate and biodegradability of organic pollutants, and application of organic fertilizer can release a large mount of DOM. The effect of dissolved organic matter （DOM） derived from various stages of crop straw decomposition on the sorption behavior of Bensulfuron-methyl （BSM） in soil had been studied. The results showed that （i） linear model can completely explained the mechanism of the BSM sorption; （ii） Within the selected concentration range of the BSM and DOM in this study, the sorption capacity of soil BSM reduced significantly after applying DOM into soil, which derived from different decomposing stages. Furthennore, there is significant difference （p〈0.01） comparing to control treatment （i.e., no DOM in sorption course）. The effect of DOM on the sorption capacity of soil BSM was weakened with longer DOM decomposition time; （iii）the role of hydrophilic fraction and hydrophobic fraction of DOM on the inhibit effects were different; （iv） the adsorbed free energy of BSM in soil were all less than 40 kJ·mol^-1,could infer that it belonged to the physical adsorption, its sorption mechanism could be the action of H-bonds, hydrophobic bonding, dipolar action force and van de Walls force, while the chemical bond sorption action was not existed.

关 键 词：溶解性有机质 土壤 吸附 苄嘧磺隆 亲水组分 疏水组分 

分 类 号：X131.3[环境科学与工程—环境科学]