Equilibrium and kinetic investigation of arsenic removal by using activated carbon produced from a waste of food industry

Water resources are running out around the world as a result of rapid population growth and industrial development. Therefore, protection of existing water resources and treatment of contaminated water is tremendously important. Arsenic, a toxic substance, is one of pollution parameters that it can cause destructive effects and death for all living organisms above the limit concentration. For that reason, the concentration of arsenic in drinking water should be at levels as low as 5-10 ppb.In this study, arsenic removal by activated carbon, which was derived from a food industry waste, peach stone, has been investigated at different pH and temperature conditions. Optimum process parameters has been determined by using experimental design methods. Adsorption equilibrium has been investigated by using Langmiur, Freundlich and D-R (Dubinin-Raduskhevich) isotherm models. First order and second order kinetic equations have been used for modeling of adsorption kinetics. Moreover, thermodynamic parameters ( ? G°, ? H°, ? S°) and mean free sorption energy (E) have been calculated and it has been tried to explain As(V) adsorption mechanism. According to the results, it was noticed that pH was very important and adsorption capacity decreased with temperature for As(V) removal by peach stone based activated carbon. Freundlich ve Dubinin-Radushkevich isotherm model better expressed the experimental data. Adsorption kinetics followed the pseudo second order kinetic equation.