Asgari
Mahvi
Vaezi
Jahed - Dept. of Environment Health Engineering, School of Public Health, Tehran University of Medical Science, Iran

Pollution of ground waters to chromium has been reported from many parts of the world. This pollution is also considered in some regions of Iran and there are various reports that indicate the existence of chromium in few water recourses of khorasan province in the form of hexavalent chromium. Removal of hexavalent chromium can be accomplished by various methods but none of them is cost-effective in meeting drinking water standards. For this study, granular ferric hydroxide (GFH) was used as adsorbent for removal of hexavalent chromium. Besides, the effects of changing contact time, pH and concentrations of competitive anions were determined for different amounts of GFH. It was found that GFH has a high capacity for adsorption of hexavalent chromium from water at pH of ≤7 and in 90 minutes contact time. The adsorbability of hexavalent chromium by GFH could be expressed by Freundlich isotherm with R2>0.968. However, the disadvantage was that the iron concentration in water was increased by the GFH material. Nevertheless, GFH is a promising adsorbent for chromium removal, even in the presence of other interfering compounds, because GFH treatment can easily be accomplished and removal of excess iron is a simple practice for conventional water treatment plants. Thus, this method is regarded as a safe and convenient solution to the problem of chromium-polluted water resources in Iran.

Adsorption, hexavalent chromium, Drinking water treatment, Granular Ferric Hydroxide (GFH)