Modeling mono- and multi-component adsorption of cobalt(II), copper(II), and nickel(II) metal ions from aqueous solution onto a new carboxylated sugarcane bagasse. Part I: Batch adsorption study

A new carboxylated-functionalized sugarcane bagasse (STA) was prepared through the esterification of sugarcane bagasse with trimellitic anhydride. The optimized synthesis conditions yield STA with a percent weight gain of 73.9% and the number of carboxylic acid groups accounted for 3.78 mmol/g. STA was characterized by FUR, elemental analysis, TGA, PZC, and SEM. Adsorption kinetics followed a pseudo-second-order model. The adsorption rate constant showed the following order: k(2,Ni)(2+) > k(2,cu)(2+) > k(2,co)(2+). Four mono- and multi-component isotherm models were used to model the adsorption systems. Monocomponent experimental data were fitted to Langmuir and Sips models; whereas, multicomponent data were fitted to modified extended Langmuir and P-factor models. The maximum adsorption capacities (Q(max,mono)) obtained from the Langmuir model were 1.140, 1.197, and 1.563 mmol/g for Co2+, Cu2+, and Ni2+, respectively. The competitive studies demonstrated that the multicomponent adsorption capacity (Q(max,multi)) was smaller than Q(max,mono) as a result of the interaction between the metal ions. Desorption studies showed that all metal ions could be fully desorbed from STA. (C) 2015 Elsevier B.V. All rights reserved.