Application of Carbon Sorbent Derived from an Agricultural Waste, Jackfruit Peel for the Removal of Cd(II) from Aqueous Solution and Plating Industry Wastewater

摘要

The present study intends to manage and utilize an agricultural waste, peel of jackfruit (Artocarpus heterophyllus) for the removal of cadmium(II) from aqueous solution and plating industry wastewater. A carbonaceous sorbent (JPC) prepared by treating jackfruit peel with sulphuric acid was systematically characterized and evaluated for its Cd(II) removal efficacy by conducting batch experiments involving process parameters like agitation time, initial metal concentration, carbon dose and pH. The contact time and varying initial metal concentration studies were modeled, respectively, with various kinetic (Lagergren's pseudo first order, Ritchie second order and modified second order models) and isotherm (Freundlich, Langmuir and Langmuir-Freundlich models) equations by a nonlinear optimization method using GNUPLOT program to find out which of these models would best define the experimental data and to derive sorption parameters for the present system. The rate of sorption was controlled by both film and intraparticle diffusion processes. The effect of sorbent dose revealed that an optimum dose of 1.2 g/L was required for the maximum removal (92%) from 40 mg/L of Cd(II) solution. A mathematical relationship, which would help to predict the percentage Cd(II) removal for any JPC dose within particular experimental conditions, was also computed. Maximum removal was registered in the pH range of 5-10 and as the pH decreased the adsorption capacity also decreased. Complete recovery of the sorbed metal from the carbon was obtained using 0.01 M HCl. The Cd(II)-JPC sorption system was applied to real cadmium plating industry wastewater and was found effective.