Competitive sorption behavior of copper(II) and herbicide propisochlor on humic acids.
The competitive sorption behavior of Cu2+ and propisochlor on humic acids (HA) was investigated using a batch method. The sorption equilibrium time of propisochlor on HA was 12 h when its initial concentration was 4 or 10 mg L(-1). The results showed that the Langmuir model can best describe the sorption behavior of propisochlor on HA. The added Cu2+ reduced the solid-phase concentration of propisochlor on HA, and the Langmuir model can also describe the sorption behavior of propisochlor on HA when the Cu2+ concentration is 100 and 200 mg L(-1). The sorption of propisochlor on HA did not remarkably affect the sorption of Cu2+ on HA when the concentration of propisochlor was below 20 mg L(-1). Cu2+ may compete with propisochlor for the sorption sites of HA, such as carboxylic and phenolic groups. It can be concluded that Cu2+ fast adsorbed to the HA matrix, altered its physical and chemical properties, and thus decreased the solid-phase concentrations of propisochlor on HA. In natural water, Cu2+ may promote the release of propisochlor from HA, and thus affect its transport, transformation, and fate in the environment.
Xu
Zhonghou
Z
Department of Soil Pollution Control, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Huang
Manxiang
M
Gu
Qingbao
Q
Wang
Yu
Y
Cao
Yunzhe
Y
Du
Xiaoming
X
Xu
Duanping
D
Huang
Qing
Q
Li
Fasheng
F
D000081:Acetamides / Q000737:chemistry*; D000327:Adsorption; D001667:Binding, Competitive; D003300:Copper / Q000737:chemistry*; D006812:Humic Substances; D008956:Models, Chemical; D015394:Molecular Structure
D000081:Acetamides; D006812:Humic Substances; D003300:Copper; C470819:propisochlor