Investigation of fixed bed adsorption column operation parameters using a chitosan material for treatment of arsenate contaminated water

According to the World Health Organization, arsenic is one of the most toxic elements for human health and the concentration limits of this pollutant are hardly attained in drinking water over the world. Arsenic(V) contaminated water at pH 8.0 was treated using a fixed bed column filled with a chitosan adsorbent material, where the operating experimental column conditions were studied. The effects of bed diameter, bed depth, arsenic inlet concentration, flow direction and flow rate were studied using breakthrough curves (BTC) acquired in real-time using a chromatographic instrument. Thomas, Yoon-Nelson and Adams-Bohart models were used to model the BTC which were best described by the two first models. Experimental data showed that dynamic adsorption capacities were dependent of flow direction and inlet concentration and were independent of the other factors considered. Moreover, an enlargement of the column did not affect the maximal capacity (50 mg As g(-1)). The height and the moving rate of the exchange zone were also determined for all experimental conditions studied. Regeneration of the exhausted column can be achieved easily using a NaCl solution.