Environniental Applications of Biodegradable Hydrogel composite: Metal sorption characteristics

Abstract

The removal of toxic heavy metais from wastewater has received much attention in recent years. Several methods have been practiced for the removal of heavy metais from wastewater,and adsorption is an efficient method regarding aqueous medium. For the adsorption process,several adsorbents have been studied for their potential of metal adsorption properties and hydrogel has found to be a better adsorbent. Hydrogels are able to absorb and retain large volume of water. Also it contribute different chelating groups into the polymeric network. In many applications, hydrogels are prepared starting from acrylamide. But acrylamide cannot be widely used, because of their difficult degradation and the high cost. The present study focuses on use of biodegradable hydrogel composite, with potential ability to adsorb metal ions from wastewater, made from Carboxymethylcellulose (CMC) using radiation processing. Batch experiments were conducted to determine the factors affecting the adsorption of the process. The optimum operating conditions, equilibrium data and adsorption kinetics for the removal of Cadmium using CMC composite were obtained. Atomic Absorption Spectrophotometer with an air-acetylene flame and Cadmium hollow cathode lamp were used for metal ion analysis. The adsorption capacity was highest at solution pH range 4 - 5 .Kinetic studies revealed that Cd uptake was fast within first 3 hours of contact time. The equilibrium data were satisfactorily fitted to Freundlich isotherm. The studies show that the incorporation of CMC introduced the metal ions adsorptive property into composite. From these preliminary evaluations, it is possible to conclude that these materials have potential for application in the effluent treatment.