Kinetic and mechanism of arsenic ions removal by adsorption on leonardite char as low cost adsorbent material

Abstract

Adsorption is one of the important techniques in arsenic removal from aqueous solutions. In this study, the As removal efficiency of Leonardite char by a prepared Leonardite carbonized at 450oC was investigated as a function of solution pH, contact time, kinetic and As(III) or As(V) concentration. The surface complexation modeling was used to describe As(III) and As(V) adsorption on the minerals which found in Leonardite char. In the batch experiment, 10.0 mg/L As(III) or As(V) pH 7.0 and 50 mL of aqueous solution was as high as 90% adsorbed. The results showed that Leonardite char could be used as effective adsorbent for the removal of arsenic from aqueous solution. This research supports effort to water with arsenic level lower than 10 mg/L. The maximum adsorption capacity was calculated by fitting the Langmuir and Freunchlich equations to the adsorption isotherms. The Leonardite char will be used as a low-cost adsorbent, for arsenic ions removal in water.