A prudent approach for the removal of copper (II) and cadmium (II) ions from aqueous solutions using indigenous Mactra aequisulcata shells

Abstract

In this study, the raw seashells of Mactra aequisulcata, of the class Bivalvia and the phylum Mollusca were employed as an adsorbent to remove copper (II) and cadmium (II) metal ions from aqueous solution. The characterization of shells was performed using FTIR, EDX and SEM, BET isotherm and point of zero charge (pHpzc). Batch experiments were performed to assess various factors on the biosorption efficiency. Maximum adsorption of both metals ions conveniently found at 0.4 g L-1 adsorbent dose, pH 5 and at 303 K. Maximum biosorption capacities for Cu2+ and Cd2+ were 59.57 and 38.12 mg g-1, respectively. The Langmuir isotherm model was found to be the best fit for the acquired equilibrium data. Thermodynamic and kinetic parameters showed that the process was feasible, exothermic and followed pseudo-first order.