Evaluation of polymer-zeolite-based composite adsorbent for heavy metal removal in batch reactor

The uncontrolled increase in human population and industrialization resulted wastes materials that lead pollution. Heavy metals are hazardous wastes which are resources of toxicity. Since heavy metals threat environment, accumulate in food chain and have toxic effects at quite low doses, they are serious pollution required to be removed. Although there are lots of methods used for heavy metal removal from water, adsorption can be a good alternative if the adsorbent is natural and economic. Recently, studies are focused on natural adsorbent and thus, alginates are getting attention. Since alginate like cheap adsorbents' heavy metal removal capacities are not enough to use them in real applications, researches are continued to seek more efficient adsorbents. In this study, in order to increase adsorption capacity of alginate, clinoptilolite, which has abundant source in our country, is selected. In this context, it is aimed to remove Cu2+, Cd2+, Pb2+ heavy metals from a synthetic wastewater by using alginate-clinoptilolite (A-C) beads in batch reactors. The best removal efficiencies were obtained by A-C (<100µm) and ratio of 1g/1g. Adsorption equilibrium times for Cu2+ and Cd2+ were 24 hours while it was 8 hours for Pb2+. Adsorption kinetics are determined to compatible with pseudo-second order model. To determine the effect of pH, experiments were performed at pH 3-5 and similar efficiencies were obtained. Adsorption of these metals are matched to Langmuir and Freundlich isotherms with the highest adsorption capacity for Pb+2 as 208 mg/g.