%0 Journal Article %T Biosorption of lanthanum and cerium from aqueous solutions using tangerine (Citrus reticulata) peel: Equilibrium, kinetic, and thermodynamic studies %A Torab-Mostaedi Meisam %J Chemical Industry and Chemical Engineering Quarterly %D 2013 %I Association of the Chemical Engineers %R 10.2298/ciceq120128043t %X Biosorption of lanthanum (III) and cerium (III) from aqueous solution by tangerine (Citrus reticulate) peel has been investigated in a batch system as a function of pH, biosorbent dosage, contact time, and temperature. The equilibrium pH was found to severely affect the biosorption performance; pH 5.0 is found to be an optimum pH for favorable biosorption of La (III) and Ce (III). The biosorption of lanthanum and cerium was investigated by the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. Maximum biosorption uptakes, according to the Langmuir model, were obtained as 154.86 and 162.79 (mg/g) for La(III) and Ce(III), respectively. The biosorption kinetic was tested with pseudo-first order and pseudo-second order models. The results showed that the kinetic of biosorption process was described by the pseudo-second order model very well. Thermodynamic parameters including the change of Gibbs free energy (¦¤G¡ã), enthalpy change (¦¤H¡ã) and entropy change (¦¤S¡ã) for both sorption systems were determined at four different temperatures. The results showed that the biosorption of La(III) and Ce(III) on tangerine (C. reticulate) peel is a spontaneous and endothermic process. FTIR analysis demonstrated that carboxyl and hydroxyl groups were involved in the biosorption of the metal ions. %K biosorption %K lanthanum %K cerium %K isotherm %K kinetic %K tangerine (Citrus reticulate) peel %U http://www.doiserbia.nb.rs/img/doi/1451-9372/2013/1451-93721200043T.pdf