Activated carbon/iron oxide composites for the removal of atrazine from aqueous medium.

The adsorption features of activated carbon and the oxidation properties of iron oxides were combined in a composite to produce new materials for atrazine removal from aqueous medium. Activated carbon/iron oxide composites were prepared at 1/1 and 5/1 mass ratios and characterized with powder X-ray diffractometry (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and nitrogen adsorption measurements. The adsorption and oxidation processes were evaluated in batch experiments, in order to monitor the atrazine removal capacity of these composites. The main iron oxide actually present in the composites was goethite (alpha-FeOOH). Impregnation with iron oxide reduced the surface area by its deposition in the activated carbon pores. However, a higher iron concentration promoted a higher oxidation rate, indicating that the efficiency of the oxidation reaction is related with the iron content and not with the pre-concentration of the contaminant on the carbon surface through adsorption process.