Chen J Paul, Yang Lei
Division of Environmental Science and Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
Langmuir. 2006 Oct 10;22(21):8906-14. doi: 10.1021/la060770+.
In this study, raw and formaldehyde-modified Sargassum sp. are used for heavy metal removal. A series of experiments shows that the chemical modification by formaldehyde improves biosorption capacity by approximately 20%. Solution pH plays an important role in the metal uptake. According to X-ray photoelectron spectroscopic and Fourier transform infrared spectroscopic analysis, the possible organic functional groups in the metal binding include carboxyl, ether, alcoholic, hydroxyl, and amino functional groups. A new model that includes a series of coordination reactions among a generalized functional group, alkaline earth metal ions and heavy metal ions, is developed for simulation of biosorption process. The model well describes the single- and multiple-species metal biosorption process under different conditions such as pH. The biosorption of heavy metals is due to the ion exchange between the heavy metals and alkaline earth metals and their adsorption onto the free sites of the seaweeds. Slightly more than half of the metal uptake is due to ion exchange. The metal affinity for the functional groups follows a descending order of lead > copper > alkaline earth metal.
在本研究中，使用未经处理的和经甲醛改性的马尾藻属海藻进行重金属去除。一系列实验表明，甲醛进行的化学改性使生物吸附容量提高了约20%。溶液pH值在金属吸收过程中起着重要作用。根据X射线光电子能谱和傅里叶变换红外光谱分析，金属结合中可能的有机官能团包括羧基、醚基、醇基、羟基和氨基官能团。开发了一个新模型，该模型包括广义官能团、碱土金属离子和重金属离子之间的一系列配位反应，用于模拟生物吸附过程。该模型很好地描述了在不同条件（如pH值）下的单物种和多物种金属生物吸附过程。重金属的生物吸附是由于重金属与碱土金属之间的离子交换以及它们在海藻自由位点上的吸附。略多于一半的金属吸收是由于离子交换。金属对官能团的亲和力顺序为铅>铜>碱土金属。
