Development of GAC-Iron Adsorbent for Arsenic Removal

Activated carbon impregnated with iron has shown significant improvement in arsenic adsorption capacity and has been studied extensively for removing arsenic from drinking water. However, achieving even distribution of impregnated iron on internal surfaces of granular activated carbon (GAC) is still a challenge for producing GAC-iron with high iron content as well as superior arsenic adsorption capacity. In this research, a new iron impregnation method was developed to achieve high amounts of iron and even iron distribution in GAC. Scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS) were used to evaluate the distribution of iron in GAC. The arsenic adsorption capacity of GAC-Iron was evaluated in batch experiments using arsenate as the adsorbate. The pH of isotherm tests was controlled at the neutral by bicarbonate buffer solution in order to keep conditions close to those of natural water.