Qin Fei, Wen Bei, Shan Xiao-Quan, Xie Ya-Ning, Liu Tao, Zhang Shu-Zhen, Khan Shahamat U
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
Environ Pollut. 2006 Nov;144(2):669-80. doi: 10.1016/j.envpol.2005.12.036. Epub 2006 Apr 17.
Combined use of batch equilibration adsorption and X-ray absorption spectroscopy (XAS) was employed to study the mechanisms of competitive adsorption of Pb, Cu, and Cd on Danish and Heilongjiang peat in single- and multi-solute systems. The adsorption capacity and initial adsorption rate on the same peat in single-solute systems followed the order Pb>Cu>Cd. Both the adsorbed amount of each metal (q'm) and its initial adsorption rate were decreased in multi-solute systems. It was observed that the adsorbed amounts of metals at low-energy adsorption sites (qm,1) decreased pronouncedly compared to those at high-energy adsorption sites (qm,2), indicating that the competitive adsorption of Pb, Cu and Cd occurred mainly at the low-energy adsorption sites. XAS study revealed that both Pb and Cu were coordinated in peat predominantly to carboxylic moieties without excluding the hydroxyl groups, thereby providing an insight into the mechanism of competitive adsorption of Pb and Cu on peat.
采用批量平衡吸附和X射线吸收光谱（XAS）联用的方法，研究了单溶质和多溶质体系中铅、铜和镉在丹麦泥炭和黑龙江泥炭上的竞争吸附机制。单溶质体系中，相同泥炭上的吸附容量和初始吸附速率顺序为Pb>Cu>Cd。在多溶质体系中，每种金属的吸附量（q'm）及其初始吸附速率均降低。观察到，与高能吸附位点（qm,2）相比，低能吸附位点（qm,1）上金属的吸附量显著降低，这表明铅、铜和镉的竞争吸附主要发生在低能吸附位点。XAS研究表明，铅和铜在泥炭中主要与羧基配位，并不排除羟基，从而深入了解了铅和铜在泥炭上的竞争吸附机制。
