Sorption and desorption of selected phenyl urea herbicides in laboratory water-sediment systems

4th International Conference on Water Resource and Environment

地球科学;生态环境科学

Lu, G.H.^1,2 ; Hou, K.K.^2 ; Liu, J.C.^2

Water Conservancy Project and Civil Engineering College, Tibet Agriculture and Animal Husbandry University, Linzhi

860000, China^1

Key Laboratory for Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Nanjing

210098, China^2

关键词: Adsorption desorption;    Desorption hysteresis;    Distribution coefficient;    Drinking water sources;    Freundlich models;    Sorption and desorptions;    Sorption isotherms;    Taihu Lake , China;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/191/1/012021/pdf
DOI  :  10.1088/1755-1315/191/1/012021

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Diuron, isoproturon and linuron were phenyl urea herbicides (PUHs) widely used in the world to control annual weeds. The adsorption-desorption behaviors of these PUHs were investigated in lab-scale water-sediment systems set up with water and sediment samples collected from Taihu Lake, China. 12 h was selected as the equilibrium time for the six sediments. Sorption isotherms of these PUHs were well described by the Freundlich model. The sorption of three PUHs in six sediments were all linear or close to it (0.92≤n≤ 1.06). The logarithms of the normalized distribution coefficient by organic carbon (logK oc) were 2.32 for isoproturon, 2.85 for diuron and 3.02 for linuron. The sorption and desorption potentials of the three PUHs can be arranged in the following order: linuron>diuron>isoproturon. The three PUHs possess moderate to strong sorption affinities to the natural sediments in the drinking water sources in Taihu Lake. Compared to linuron and diuron, the desorption hysteresis of isoproturon is conspicuous with hysteresis indices from 0.657 to 0.872, and the sorption seems to be irreversible.