School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
J Environ Manage. 2010 Mar-Apr;91(4):958-69. doi: 10.1016/j.jenvman.2009.12.003. Epub 2009 Dec 30.
Chitosan-tripolyphosphate (CTPP) beads were synthesized, characterized and were used for the adsorption of Pb(II) and Cu(II) ions from aqueous solution. The effects of initial pH, agitation period, adsorbent dosage, different initial concentrations of heavy metal ions and temperature were studied. The experimental data were correlated with the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The maximum adsorption capacities of Pb(II) and Cu(II) ions in a single metal system based on the Langmuir isotherm model were 57.33 and 26.06 mg/g, respectively. However, the beads showed higher selectivity towards Cu(II) over Pb(II) ions in the binary metal system. Various thermodynamic parameters such as enthalpy (DeltaH degrees), Gibbs free energy (DeltaG degrees) and entropy (DeltaS degrees) changes were computed and the results showed that the adsorption of both heavy metal ions onto CTPP beads was spontaneous and endothermic in nature. The kinetic data were evaluated based on the pseudo-first and -second order kinetic and intraparticle diffusion models. Infrared spectra were used to elucidate the mechanism of Pb(II) and Cu(II) ions adsorption onto CTPP beads.
壳聚糖-三聚磷酸酯(CTPP)珠粒被合成、表征,并用于从水溶液中吸附 Pb(II)和 Cu(II)离子。研究了初始 pH 值、搅拌时间、吸附剂用量、不同初始重金属离子浓度和温度的影响。实验数据与 Langmuir、Freundlich 和 Dubinin-Radushkevich 等温模型相关联。基于 Langmuir 等温模型,在单一金属体系中,Pb(II)和 Cu(II)离子的最大吸附容量分别为 57.33 和 26.06 mg/g。然而,在二元金属体系中,珠粒对 Cu(II)表现出比 Pb(II)更高的选择性。计算了各种热力学参数,如焓变(DeltaH degrees)、吉布斯自由能变(DeltaG degrees)和熵变(DeltaS degrees),结果表明,两种重金属离子在 CTPP 珠粒上的吸附都是自发的、吸热的。基于准一级和准二级动力学以及内扩散模型对动力学数据进行了评估。红外光谱用于阐明 Pb(II)和 Cu(II)离子吸附到 CTPP 珠粒上的机制。