STUDY OF THE EFFECT OF THE BENTONITE MODIFICATION TREATMENTS ON THE ADSORPTION REMOVAL OF AMMONIUM IONS FROM AQUEOUS SOLUTION

Excessive introduction of nitrogen fertilizers and the effect of erosion on the soil contribute to the contamination of ground waters and surface waters by accumulation of the phosphorus, ammonium and other nitrogen compounds in the receptor medium. In this study, we have evaluated the performances of natural kaolin and different bentonite samples issued from different modification techniques (acid, alkali and salt) for the adsorption removal of ammonium ions from aqueous solutions. So, the results found in this work suggest that the modification treatment of the bentonite have improved both the adsorption yields which were very important for sample modified by alkaline treatment of 70.77%. The SAA analysis of the contaminated solution after the adsorption process indicates that the ammonium removal is an ion exchange between ammonium ions of the solution and sodium ions of the Na-Bentonite layer. The characterisation of the Na-Bentonite samples after exposure to ammonium ions proves this phenomenon by changing in the morphological surfaces' and appearance of new peak of stretching vibration of N-H of the adsorbed ammonium.