Removal of cobalt (II), copper (II), and nickel (II) ions from aqueoussolutions using phthalate - functionalized sugarcane bagasse : mono - and multicomponent adsorption in batch mode.

Abstract

This study describes, in detail, the chemical modification of sugarcane bagasse with phthalic anhydrideto produce a carboxylate-functionalized sugarcane bagasse (SPA). The optimized modification condi-tions yielded SPA with a percent weight gain of 77.08% and an amount of carboxylic acid groups of 4.76mmol/g. The SPA was characterized by PZC, FTIR, elemental analysis, TGA, and SEM-EDX. An SPA adsor-bent was used to remove Co2+, Cu2+, and Ni2+from aqueous solution in mono- and multicomponentsystems in batch mode. The adsorption kinetics followed a pseudo-second-order model. The adsorptionrate constants assumed the following order: k2,Co2+> k2,Ni2+> k2,Cu2+. Four mono- and multicomponentisotherm models were used to model the adsorption data. Monocomponent data were well described bythe Langmuir model, whereas bicomponent data were well described by the modified extended Lang-muir and P-Factor models. The maximum adsorption capacities (Qmax,mono) for the Langmuir model were0.561, 0.935, and 0.932 mmol/g for Co2+, Cu2+, and Ni2+, respectively. Adsorption in bicomponent systemsrevealed that Cu2+suppressed the adsorption of Co2+and Ni2+, whereas Ni2+suppressed the adsorptionof Co2+. Desorption studies revealed that the SPA adsorbent could be fully desorbed with a 1 mol/L HNO3solution.