THE REMOVAL OF CHROMIUM FROM AQUEOUS SOLUTIONS USING AN INDUSTRIAL WASTE MATERIAL

Heavy metals have toxic effects for aquatic environment and living organisms, therefore the importance for heavy metal removals from aqueous solutions increase recently. Various removal methods of heavy metals from wastewaters were used such as chemical oxidation, adsorption, membrane filtration, UV treatment etc. Adsorption process is a favorable method because of its low cost and efficiency. In this study an industrial waste material produced in boron enrichment process for concentrate colemanite production was used as an adsorbent for chromium removal from aqueous solution. The influence of adsorbent mass, pH, contact time and initial chromium concentration on the adsorption efficiency has been investigated. Maximum chromium removal was obtained as 73% at optimum conditions (adsorbent doze=2.0 g/L; shaking speed=200 rpm; original pH=5.0; contact time=30 minutes and initial chromium concentration=20 mg/L). The adsorption isotherm of waste material was fitted by Freundlich adsorption isotherm and R2 value of the isotherm was determined as 0.83.