Adsorption and desorption characteristics of endosulfan in two typical agricultural soils in Southwest China.
Endosulfan is an organochlorine pesticide widely used in Southwest China. In this paper, the adsorption and desorption characteristics of endosulfan in two typical agricultural soils (latosol and lateritic red soil) in this area were studied. The results showed that Langmuir isothermal equation could well describe the adsorption thermodynamic characteristics of endosulfan in latosol and lateritic red soil, and the maximum adsorption capacities of α-endosulfan were 0.186 and 0.209 mg/g, while those of β-endosulfan were 0.140 and 0.148 mg/g, respectively. Endosulfan adsorption in the two soils was an exothermic physicochemical process, but dominated by physical process. The adsorption kinetic characteristics of endosulfan in the two soils could be well described by second-order kinetic equation, and the initial rate constants were 0.228 and 0.325 mg/(g min) for α-endosulfan, while those were 0.119 and 0.125 mg/(g min) for β-endosulfan, respectively. The adsorbed endosulfan in the two soils was difficult to be desorbed into the liquid phase, and showed weak desorption hysteresis. These results implied that endosulfan could be firmly adsorbed by the two soils, and their adsorption and desorption abilities may be related to the contents of soil clay and organic matter.
College of Resources and Environment, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Southwest University, Chongqing, 400715, People's Republic of China.
Sheng
S
Qian
College of Resources and Environment, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Southwest University, Chongqing, 400715, People's Republic of China.
Heng
H
Zhu
College of Resources and Environment, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Southwest University, Chongqing, 400715, People's Republic of China.|Department of Resources and Environment, Zunyi Normal College, Zunyi, Guizhou, 563002, People's Republic of China.
Bailian
B
Xiong
Chongqing Entry-Exit Inspection and Quarantine Bureau, Chongqing, 400020, People's Republic of China.
Guocan
G
Zheng
College of Resources and Environment, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Southwest University, Chongqing, 400715, People's Republic of China. jzhzhang@swu.edu.cn.|Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, People's Republic of China. jzhzhang@swu.edu.cn.
Jinzhong
J
Zhang
College of Resources and Environment, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Southwest University, Chongqing, 400715, People's Republic of China.
Weihong
W
Xu
D000327:Adsorption; D000383:Agriculture; D002681:China; D004726:Endosulfan / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*
D012987:Soil; D012989:Soil Pollutants; D004726:Endosulfan
Adsorption; Desorption; Endosulfan; Lateritic red soil; Latosol