REMOVAL OF Cr (VI) FROM AQUEOUS SOLUTION BY POLYMER BASED GUAR GUM-G-POLY (AAm) AND ACTIVED CHARCOAL ADSORBENTS

Graft copolymerization of acryl-amide onto guar-gum has been carried out in the presence of potassium per sulphate as a redox initiator. The prepared graft copolymer was characterized by various techniques such as FT-IR, SEM-EDX and TGA-DTA-DTG. Activated charcoal was also studied as the adsorbent in the present study to evaluate their adsorption capacity for Cr (Vl) and compared it with indigenously synthesized graft copolymer. The experimental data were fitted well to Langmuir adsorption isotherm for Guar Gum-g-Poly (AAm) as well as activated charcoal. The maximum monolayer adsorption capacities for Guar Gum-g-Poly(AAm) and activated charcoal were 142.8 mg/g and 200 mg/g. Pseudo second order model was found to explain the kinetics of Cr (VI) adsorption most effectively with good correlations (R2>0.99) in both cases. Thermodynamic parameters showed that adsorption processes were spontaneous and endothermic for Guar Gum-g-Poly (AAm) and activated charcoal