Sun Xue-Fei, Wang Shu-Guang, Liu Xian-Wei, Gong Wen-Xin, Bao Nan, Gao Bao-Yu
School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
J Colloid Interface Sci. 2008 Aug;324(1-2):1-8. doi: 10.1016/j.jcis.2008.04.049. Epub 2008 Apr 27.
The biosorption process for removal of cobalt(II) and zinc(II) by aerobic granules was characterized. Single component and binary equimolar systems were studied at different pH values. The equilibrium was well described by Redlich-Peterson adsorption isotherm. The maximal adsorption capacity of the granules, in single systems (55.25 mg g(-1) Co; 62.50 mg g(-1) Zn) compared with binary systems (54.05 mg g(-1) Co; 56.50 mg g(-1) Zn) showed reduction in the accumulation of these metals onto aerobic granules. The kinetic modelling of metal sorption by granules has been carried out using Lagergren equations. The regression analysis of pseudo second-order equation gave a higher R(2) value, indicating that chemisorption involving valent forces through the sharing or exchange of electrons between sorbent and sorbate may be the rate limiting step. The initial biosorption rate indicated that aerobic granules can adsorb Co(II) more rapidly than Zn(II) from aqueous solutions. Meanwhile, FTIR and XPS analyses revealed that chemical functional groups (e.g., alcoholic and carboxylate) on aerobic granules would be the active binding sites for biosorption of Co(II) and Zn(II).
对好氧颗粒去除钴（II）和锌（II）的生物吸附过程进行了表征。在不同pH值下研究了单组分和二元等摩尔体系。用Redlich-Peterson吸附等温线很好地描述了平衡。与二元体系（54.05 mg g(-1) Co；56.50 mg g(-1) Zn）相比，单体系中颗粒的最大吸附容量（55.25 mg g(-1) Co；62.50 mg g(-1) Zn）表明这些金属在好氧颗粒上的积累有所减少。利用Lagergren方程对颗粒吸附金属的动力学进行了建模。伪二级方程的回归分析给出了更高的R(2)值，表明通过吸附剂和吸附质之间电子的共享或交换涉及价力的化学吸附可能是限速步骤。初始生物吸附速率表明，好氧颗粒从水溶液中吸附Co(II)的速度比Zn(II)快。同时，傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）分析表明，好氧颗粒上的化学官能团（如醇基和羧基）将是生物吸附Co(II)和Zn(II)的活性结合位点。
