Lodeiro P, Barriada J L, Herrero R, Sastre de Vicente M E
Departamento de Química Física e Enxeñería Química I, Universidade da Coruña, Alejandro de la Sota 1, 15071 A Coruña, Spain.
Environ Pollut. 2006 Jul;142(2):264-73. doi: 10.1016/j.envpol.2005.10.001. Epub 2005 Dec 15.
This work reports kinetic and equilibrium studies of cadmium(II) and lead(II) adsorption by the brown seaweed Cystoseira baccata. Kinetic experiments demonstrated rapid metal uptake. Kinetic data were satisfactorily described by a pseudo-second order chemical sorption process. Temperature change from 15 to 45 degrees C showed small variation on kinetic parameters. Langmuir-Freundlich equation was selected to describe the metal isotherms and the proton binding in acid-base titrations. The maximum metal uptake values were around 0.9 mmol g(-1) (101 and 186 mg g(-1) for cadmium(II) and lead(II), respectively) at pH 4.5 (raw biomass), while the number of weak acid groups were 2.2 mmol g(-1) and their proton binding constant, K(H), 10(3.67) (protonated biomass). FTIR analysis confirmed the participation of carboxyl groups in metal uptake. The metal sorption was found to increase with the solution pH reaching a plateau above pH 4. Calcium and sodium nitrate salts in solution were found to affect considerably the metal biosorption.
本研究报告了褐藻囊链藻对镉（II）和铅（II）的吸附动力学及平衡研究。动力学实验表明金属吸收迅速。动力学数据通过伪二级化学吸附过程得到了满意的描述。温度从15℃变化到45℃时，动力学参数变化较小。选择朗缪尔-弗伦德里希方程来描述金属等温线以及酸碱滴定中的质子结合。在pH 4.5（原始生物质）时，最大金属吸收值约为0.9 mmol g⁻¹（镉（II）和铅（II）分别为101和186 mg g⁻¹），而弱酸基团数量为2.2 mmol g⁻¹，其质子结合常数K(H)为10³·⁶⁷（质子化生物质）。傅里叶变换红外光谱分析证实了羧基参与了金属吸收。发现金属吸附随着溶液pH值的升高而增加，在pH值高于4时达到平稳状态。溶液中的硝酸钙和硝酸钠盐被发现对金属生物吸附有显著影响。
