Abstract

The present study deals with the adsorptive removal of nickel ions from liquid phase hydrocarbons by unmodified and NaOH modified activated carbon developed from coconut shell. The activated carbon was characterized and investigated for the adsorption of nickel metal ions from aqueous solution. The activated carbon was characterized using Fourier-Transform Infra Red spectroscopy (FTIR) and scanning electron microscope (SEM). Coconut shell was used to prepare activated carbon through chemical modification. The effect of contact time and metal ion concentration on the adsorption of nickel onto unmodified and chemically modified activated coconut shell was investigated. The initial metals ion concentration ranged from 20mg/L to 150mg/L and the maximum removal was observed at metal-ions concentration 150 mg/L. The Ni (II) ion removal efficiency was 97.76% and 96.76% for modified and unmodified activated carbon. The adsorption data was analyzed by isotherm and kinetic studies. The adsorption process appeared to follow a linear and non-linear model. Langmuir and Freundlich isotherm models were used for equilibrium adsorption data. Langmuir isotherm proved to be a better fit. The linear and non-linear model for Pseudo first order and pseudo second order kinetic models were applied to analyze the kinetic mechanism of adsorption. Pseudo second order gain the dominance of chemisorption mechanism.

Key words: Adsorption, activated carbon, Nickel and Wastewater