Xu HuanYan, Yang Lei, Wang Peng, Liu Yu, Peng MingSheng
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
J Environ Manage. 2008 Jan;86(1):319-28. doi: 10.1016/j.jenvman.2006.12.011. Epub 2007 Mar 23.
The sorption of aqueous lead on carbonate-hydroxyapatite (CHAp) is a complicated non-homogeneous solid/water reaction, which from the kinetic point of view has two stages. In the first stage, the reaction rate is so fast and the kinetic pathway so intricate that further research is required. In the second stage, the reaction rate slows down and the reaction process follows that of a first-order kinetic equation. Experimental results show that the relationship between the reaction rate constant k(1) and temperature T agrees with the Arrhenius equation, and that the activation energy of sorption (E(a)) is 11.93 kJ/mol and the frequency factor (A) is 2.51/s. The reaction rate constant k(1) increases with the Pb(2+) initial concentration and decreasing pH, but with increasing CHAp dosage. X-ray diffraction (XRD), scanning electron microscopy with energy dispersion spectrum (SEM-EDS) and toxicity characteristic leaching procedure (TCLP) tests indicate that the main sorption mechanism is dissolution-precipitation, in conjunction with surface sorption.
碳酸羟基磷灰石（CHAp）对水溶液中铅的吸附是一个复杂的非均相固/水反应，从动力学角度来看有两个阶段。在第一阶段，反应速率极快且动力学路径极为复杂，需要进一步研究。在第二阶段，反应速率减慢，反应过程符合一级动力学方程。实验结果表明，反应速率常数k(1)与温度T之间的关系符合阿伦尼乌斯方程，吸附活化能（E(a)）为11.93 kJ/mol，频率因子（A）为2.51/s。反应速率常数k(1)随Pb(2+)初始浓度的增加和pH值的降低而增大，但随CHAp用量的增加而减小。X射线衍射（XRD）、带能谱的扫描电子显微镜（SEM-EDS）和毒性特性浸出程序（TCLP）测试表明，主要吸附机制是溶解-沉淀，同时伴有表面吸附。
