Arsenic Removal from Aqueous Solutions using a Binary Mixed Oxide

In the most cases the drinking water has been identified as one of the major sources of arsenic exposure by the general population. A variety of treatment processes has been studied for arsenic removal from water. One of the most used methods is the adsorption. The most efficient adsorbent materials are those with iron content considering the affinity of arsenic species towards iron compounds. In the present paper the As (III) adsorption performance of a binary mixed oxide Fe(2)O(3)-SiO(2) was investigated. The sorption process is best described by the pseudo-second-order kinetics. The theoretically predicted equilibrium adsorption capacity was close to the experimentally determined value (80.6 mu g/g). Modeling of the equilibrium data with Freundlich and Langmuir isotherms lead to a better correlation coefficient in the case of Langmuir model. The value of the calculated maximum adsorption capacity is close to the experimental value (340 mu g/g). The dimensional separation factor used to predict the essential characteristics of Langmuir isotherm indicates favorable adsorption in the studied concentration range (100-700 mu g As (III) / L). The studied binary mixed oxide develops promising adsorbent properties concerning the arsenic (III) removal from aqueous medium.