Nitrate Removal from Water Using Granules Ferric Hydroxide Absorbent

One of the major sources of drinking water contamination is nitrate. Nitrate concentrations of more than the standard levels (45mgl-1 based on nitrate) could cause methemoglobinemia in children. The aim of this study is to investigate the nitrate adsorption on granular ferric hydroxide (GFH). Also in this study, the effect of factors such as initial concentration of nitrate, contact time, adsorbent mass and particle size of adsorbent were determined.

This study was conducted in a laboratory-scale in which the synthetic nitrate solutions were placed in a batch reactor, in contact with the adsorbent to model the adsorption kinetics.

The findings of the study indicated that by increasing Nitrate‘s initial concentration, sorption capacity reaches to the maximum level in a short time of two to three minutes. Increasing the amount of adsorbent and decreasing the adsorbent particle size could reduce the adsorption capacity. Also, the absorption kinetics followed the pseudo-degree reaction model.

This removal method could decrease nitrate concentrations to less than the standard level (45mgl-1 based on nitrate). Easy operation and high adsorption capacity of GFH are the advantages of this removal method.