Removal Of Chromium (VI) From Aqueous Solutions Using Chitosan Coated Kaolıne Beads As

Various physicochemical process such as filtration, ion exchange, chemical precipitation, and membran systems are used in treatment of waste waters including heavy metals. Among these processes, adsorption technique is more economical process and has some advantages over the other techniques. Recently, researchers have many studies on the low cost and easily obtainable adsorbents. In this study, the usege of chitosan coated kaoline composite beads as low-cost adsorbent to removal of Cr(VI) ions from the aqueous solutions has been investigated. The effects of pH, sorbent dosage, initial metal concentration and contact time on the adsorption of Cr(VI) from aqueous soluiton using the chitosan coated kaoline beads were studied systemically. The pH of the solution was varied over a range of 2-6 and the adsorption of Cr(VI) ions on chitosan coated kaoline beads was determined to be pH-dependent. The Freundlich and Langmuir adsorption isotherm models were applied to describe equilibrium data. The data fitted well with Langmuir model and maximum adsorption capacity of chitosan-coated kaoline beads was determined to be 31,98 mg/g for Cr(VI) at 120 sec. of contact time.