Nitrate Removal from Drinking Water Using Modified Natural Clays

High level of nitrate in the water resources causes some health and environmental problems. The objective of this study was to remove nitrate from drinking water using modified natural clays. Natural clay (bentonite) was modified with HCl (2N), H2SO4 (2N) and H2SO4 (4N).Structure and morphology of bentonite was determined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Adsorption process was accomplished in a batch with emphasis on the effect of various parameters such as contact time, pH, adsorbent dosage and nitrate concentration on adsorption efficiency. In order to understand the adsorption process, equilibrium isotherms were also determined. The results showed that maximum nitrate adsorption achieved for adsorbent modified with H2SO4(4N)and optimum pH and contact time were found 4 and 60 min respectively. The obtained data showed the most correlation with Freundlich model. Finally, finding of this study suggested that the adsorbent modified with H2SO4 (4N) is a suitable and effective adsorbent to remove nitrate from drinking water.