Application of modified activated carbon by some metals chloride in removal of nitrate ion from drinking water

Nitrate removal from aqueous solution was investigated using granular activated carbon (GAC) modified with mixture of ZnCl2, CaCl2 and MgCl2. Influence of contact time, adsorbent dose, nitrate concentration, pH and temperature were investigated. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir isotherm model explained the sorption process well and showed the best coefficient of determination (0.9947). The nitrate sorption kinetic data were successfully fitted to pseudo-second order kinetic model. Adsorption was maximum in the pH range 4-8. The overall results demonstrated potential applications of modified GAC for nitrate removal from aqueous solutions.