Effective removal of nitrate ions from aqueous solution using new clays: Tamazert kaolin treated under microwave irradiation

Abstract

In this work, we have suggested two low cost modifications on mineral clay, based on the kaolin of Jijel. These modifications aim to remove the nitrate from contaminated water by adsorption. The modified adsorbent clays are prepared respectively as follows, activation by Phosphoric acid under microwave irradiation for the first (KH +) and by mixing the kaolin with lime under microwave irradiation for the second (K-lime). The adsorbents are characterized by X-ray diffraction, Laser particle size analyzer, Fourier Transform Infrared (FTIR) and Scanning electron microscopy (SEM). The adsorption experiments on clays are carried out in batch using synthetic nitrate solution. A study of adsorption kinetic showed that the adsorption equilibrium is reached in 1 h for KH + and 50 min for K-lime and the optimum pH value is 4 for both adsorbents. Adsorption process is done according to pseudo-second order. The adsorption capacity of K-lime is better, with an adsorption rate of 75%, than that of KH + , where the rate is about 42%.