719n Separation Characteristics of Chromium Ion Onto Natural Polymer

Tae Young Kim, Jae-hoon Chung, Seung-Shik Park, Byoung-Jun Min Min, Sung-Yong Cho, and Seung-Jai Kim. Environmental Engineering, Chonnam National University, 300 YongBong-Dong Buk-Gu, Gwangju, 505-757, South Korea

Chromium is one of the most strategic and critical materials having a wide range of use in the various industries. Hexavalent chromium is generally found in the chemical industry as an oxidizing agent, metallurgical industry for chrome alloy of chromium metal production, electroplating, corrosion control and photography. On the other hand, trivalent chromium is extensively used in leather tanning industry, paints and pigments industry, fungicides industry and ceramic or glass manufacture. Cr(VI) is known to be toxic to both plants and animals, as a strong oxidizing agent and potential carcinogen. Although Cr(III) is nontoxic or less toxic than Cr(VI), a long-term exposure to trivalent chromium is known to cause allergic skin reactions. Wastewater containing relatively low concentration of Cr(VI) is usually treated with ion-exchange resin which has the advantage of the recovery of chromic acid and also disadvantage of high cost of resin. As an alternative to this, sorption has recently gained more attention due to its possibility to overcome this problem. In several recent publications, various authors have reported the use of different sorbents for trivalent chromium removal using such as: chitosan impregnated microemulsions, sunflower stalks, seaweed biomass. In a similar manner, hexavalent chromium removal was investigated by employing composite chitosan biosorbent, granular activated carbon, immobilized fungal biomass. The sorption of trivalent and hexavalent chromium mixture was effective by few sorbents such as seaweed biosorbent and layer silicates. Recently, the possibility of both chromium species removal from tannery effluents was studied, by the use of calcium alginate beads containing humic acid, in a toxicological approach. The main purpose of this work is to eliminate chromium ion from its aqueous solution using alginate bead and to study its adsorption characteristics experimentally as well as theoretically.