Sorption of Anionic Metsulfuron-Methyl and Cationic Difenzoquat on Peat and Soil As Affected by Copper

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• 作者：Zhiguo Pei ; Xiao-Quan Shan ; Bei Wen ; Bo He ; Tao Liu ; Yaning Xie ; Gary Owens
• 刊名：Environmental Science & Technology
• 出版年：2008
• 出版时间：September 15, 2008
• 年：2008
• 卷：42
• 期：18
• 页码：6849-6854
• 全文大小：179K
• 年卷期：v.42,no.18(September 15, 2008)
• ISSN：1520-5851

文摘

The effect of cationic copper (Cu²⁺) on the sorption of anionic metsulfuron-methyl (Me) and cationic difenzoquat (DZ) to peat and soil was studied using a batch equilibration method. The results showed that Cu²⁺ increased the sorption of Me but diminished the sorption of DZ. The adsorption of Cu²⁺ on the surface of peat and soil neutralizes the negative charge, making the zeta potential (ζ) of peat and soil less negative, consequently decreasing the repulsion between the surface of peat or soil and Me and increasing the sorption of Me. Cu²⁺ may additionally form Cu−Me complexes in aqueous solution, which was preferentially sorbed to peat and soil over the anionic Me. In contrast, the decreased negative surface charge of soil and peat does not favor the sorption of cationic DZ. Fourier transform infrared showed that DZ may be sorbed through interaction with −OH or −COOH groups of peat and soil and that surface complexes of Cu²⁺ may form through these groups. A competitive sorption between Cu²⁺ and DZ for the same sorption sites is indicated, leading to mutual sorption inhibition of both cations.