pH对湿地水环境中生物膜吸附铅和镉的影响

Effect of pH on Pb and Cd Adsorption to Surface Coatings Developed in the Aquatic Environment of Wetland

利用向海自然保护区一苇塘培养的生物膜在不同 p H值条件下进行铅、镉的吸附 ,通过 Freundlich和 L angmuir等温吸附曲线描述生物膜吸附铅、镉的热力学过程 .实验结果表明 ,不同 p H条件下 ,铅、镉在湿地水环境中培养的生物膜吸附热力学数据均与 Freundlich和 Langmuir等温吸附曲线显著性相关 ( n=5,p<0 .0 1 ) ,生物膜吸附铅的能力比吸附镉的能力约大一个数量级 ,吸附溶液中的 p H值与铅、镉的最大吸附量呈正比 。

Pb and Cd adsorption on the surface coatings in the pH range from 4.5 to 7.0, which were cultivated in a reed pond in Xianghai, was carried out. The data of Pb and Cd adsorption on the surface coatings fit both Freundlich and Langmuir isotherms very well (n=5, p=0.01), and the maximum adsorption of Pb on the surface coatings is one order of magnitude greater than that of Cd. Meanwhile, the maximum adsorption of Pb and Cd on the surface coatings increases with increase of pH in the solutions, showing significant linear correlation.