Sekar M, Sakthi V, Rengaraj S
Department of Chemistry, N.G.M. College, Pollachi 642 001, Tamil Nadu, India.
J Colloid Interface Sci. 2004 Nov 15;279(2):307-13. doi: 10.1016/j.jcis.2004.06.042.
Removal of lead from aqueous solutions by adsorption onto coconut-shell carbon was investigated. Batch adsorption experiments were performed to find out the effective lead removal at different metal ion concentrations. Adsorption of Pb2+ ion was strongly affected by pH. The coconut-shell carbon (CSC) exhibited the highest lead adsorption capacity at pH 4.5. Isotherms for the adsorption of lead on CSC were developed and the equilibrium data fitted well to the Langmuir, Freundlich, and Tempkin isotherm models. At pH 4.5, the maximum lead adsorption capacity of CSC estimated with the Langmuir model was 26.50 mg g(-1) adsorbent. Energy of activation (Ea) and thermodynamic parameters such as DeltaG, DeltaH, and DeltaS were evaluated by applying the Arrhenius and van't Hoff equations. The thermodynamics of Pb(II) on CSC indicates the spontaneous and endothermic nature of adsorption. Quantitative desorption of Pb(II) from CSC was found to be 75% which facilitates the sorption of metal by ion exchange.
研究了通过吸附到椰壳炭上从水溶液中去除铅的方法。进行了批量吸附实验，以确定在不同金属离子浓度下的有效铅去除率。Pb2+离子的吸附受pH值的强烈影响。椰壳炭（CSC）在pH 4.5时表现出最高的铅吸附容量。建立了铅在CSC上吸附的等温线，平衡数据与Langmuir、Freundlich和Tempkin等温线模型拟合良好。在pH 4.5时，用Langmuir模型估计的CSC的最大铅吸附容量为26.50 mg g(-1)吸附剂。通过应用Arrhenius方程和van't Hoff方程评估了活化能（Ea）和热力学参数，如ΔG、ΔH和ΔS。Pb(II)在CSC上的热力学表明吸附是自发的且吸热的。发现从CSC上定量解吸Pb(II)的比例为75%，这有利于通过离子交换吸附金属。
