The use of a wetland plant as a new biosorbent for treatment of water contaminated with heavy metals: Nonlinear analyses, modification, competitive effects

Abstract

Abstract The aimof this study was to evaluate the biosorption capacity of a wetland plant Juncus effusus for elimination of toxic heavy metals such as Cd 2 + and Cu 2 + from aqueous solutions. The effects of pH, biosorbent amount, biosorption time, heavy metal concentration, ionic strength, humic acid (HA), modification and competitive metal ions such as cadmium, lead, copper and zinc on biosorption efficiency were investigated in a batch biosorption process. J. effusus biomass was characterized by using SEM analysis and FT-IR spectra. The Freundlich, Langmuir and Temkin isotherm models were used to describe the biosorption equilibrium of Cd 2 + and Cu 2 + for J. effusus. The isotherms of biosorption of Cu 2 + and Cd 2 + ions were best described by the Freundlich and Langmuir models, respectively. The kinetic data of biosorption were modeled with the Elovich, the pseudo-first-order, pseudo-second-order and intra-particle diffusion model equations. The kinetic data were successfully described by the pseudo-first-order model. The biosorption processes, which used sodium hydroxide as the chemical modification material, exhibited the best performance in a wide pH range (4–7). The results confirmed that the biosorbent, which was prepared out of a wetland plant, could be used as an inexpensive and abundant biosorbent for removing metal ions from waters contaminated with heavy metals.