Adsorption characteristic of bensulfuron-methyl at variable added Pb^(2+) concentrations on paddy soils  

作　　者：WU Weihong WANG Haizhen XU Jianming XIE Zhengmiao 

机构地区：[1]Department of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018, Chin [2]College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029, China [3]Zhejiang Provincial Key Laboratory of Subtropic Soil Science and Plant Nutrition, Hangzhou 310029, China

出　　处：《Journal of Environmental Sciences》2009年第8期1129-1134,共6页环境科学学报（英文版）

基　　金：supported by the National Nature Science Foundation for Distinguished Young Scholars of China(No. 40425007);the National Natural Science Founda-tion of China (No. 40371062, 40771100);the Natural Science Foundation of Zhejiang Province (No. Y5080180)

摘　　要：The combined pollution of heavy metal Pb^2＋ and bensulfuron-methyl （BSM）, originating from chemical herbicides, in agroecological environments has become commonplace in southern China. The adsorption of BSM on three paddy soils in the presence of Pb^2＋ was examined using high-performance liquid chromatograph （HPLC）. Results indicated that adsorption of BSM could accurately be described by a Freundlich isotherm equation with correlation constant （R） 〉 0.98, irrespective of the presence of spiked Pb^2＋. Of the various factors influencing BSM sorption, soil pH appeared to be the most influential. The constant Kf of Freundlich isotherm equation tended to increase with increasing Pb^2＋ concentration in soil which indicated that the spiked of Pb^2＋ in paddy soils would promote the sorption of BSM. AGo of BSM in three paddy soils was less than 40 kJ/mol in all treatments, indicating the adsorption of BSM is mainly physical in nature. The elution of soil dissolved organic matter （DOM） enhanced the adsorption of BSM in paddy soils. The mechanisms involved in the promotion effects of the spiked Pb^2＋ on BSM adsorption might be the modified surface characteristics of paddy soil solids due to the soil acidification and the increase of soil organic matter concentration because of DOM binding.The combined pollution of heavy metal Pb^2＋ and bensulfuron-methyl （BSM）, originating from chemical herbicides, in agroecological environments has become commonplace in southern China. The adsorption of BSM on three paddy soils in the presence of Pb^2＋ was examined using high-performance liquid chromatograph （HPLC）. Results indicated that adsorption of BSM could accurately be described by a Freundlich isotherm equation with correlation constant （R） 〉 0.98, irrespective of the presence of spiked Pb^2＋. Of the various factors influencing BSM sorption, soil pH appeared to be the most influential. The constant Kf of Freundlich isotherm equation tended to increase with increasing Pb^2＋ concentration in soil which indicated that the spiked of Pb^2＋ in paddy soils would promote the sorption of BSM. AGo of BSM in three paddy soils was less than 40 kJ/mol in all treatments, indicating the adsorption of BSM is mainly physical in nature. The elution of soil dissolved organic matter （DOM） enhanced the adsorption of BSM in paddy soils. The mechanisms involved in the promotion effects of the spiked Pb^2＋ on BSM adsorption might be the modified surface characteristics of paddy soil solids due to the soil acidification and the increase of soil organic matter concentration because of DOM binding.

关 键 词：BENSULFURON-METHYL ADSORPTION paddy soils Pb pollution 

分 类 号：S155.292[农业科学—土壤学] X703[农业科学—农业基础科学]