Adsorptive removal of chromium (vi) from water using activated carbon of enseteventricosum midrib leaf and erythrina abyssinica

Abstract

Discharge of chromium containing water solution into the environment poses a serious environmental and health problem. There is need for environmentally friendly and cost-effective methods for removal of chromium containing water. The main objective of present study is to investigate the adsorptive removal of chromium (VI) from aqueous solution using activated Carbon of Erythrinaabyssinica (AC-EA) &Enseteventricosummidrib leaf (AC-EVML) because it is high removal capacity, low cost and easy accessibility. Activated Carbon EVML and EA adsorbents were prepared Sulfuric acid activation method at 100 0C. Characterization of these adsorbents such as physicochemical parameter, point pf zero charge, Fourier transform infrared radiation spectroscopy, surface area and X-ray diffraction was done prior to bio sorption process. activated adsorbents were assessed in batch mode adsorption experiment for percentage chromium removal and milligrams per gram chromium uptake as a function of contact time, pH, and initial concentration. Results showed maximum removal efficiency for Cr (VI) at 9 h and 6 h contact time, by AC-EVML and AC-EA, respectively at 0.1 g and pH 2. Percentage removal of Cr (VI) increased with increasing contact time (from 0.5 h to 12 h). Sorption kinetics of chromium adsorption by activated adsorbents was predicted reliably using a pseudo-first order, pseudo-second order and intra particle diffusion model. The kinetic adsorption data well fitted to pseudo-second order. Equilibrium uptakes were evaluated using Langmuir, Freundlich and Temkin adsorption isotherm models and the equilibrium data well fitted into Langmuir isotherm. The study demonstrated the efficiency of activated adsorbents and presents it as a viable low-cost adsorbent for bioremediation.