ADSORPTIVE REMOVAL OF Cr (VI) FROM AQUEOUS SOLUTION USING RUBBER SEED SHELL CHARCOAL

Charcoal samples were prepared from rubber seed shell, an agricultural waste, for the removal of Cr (VI) ions. The adsorption characteristics of chromium (VI) ions from aqueous solution on to activated rubber seed shell charcoal (RSC), acid treated rubber seed shell charcoal (ARSC), chitosan coated rubber seed shell charcoal (CRSC), and chitosan coated acid treated rubber seed shell charcoal (CARSC) were investigated. The effect of pH of chromium solution, adsorbent dosage and contact time on adsorption rates were studied in batch experiment. Results showed that chemically modified adsorbents with oxidizing agents or chitosan have better chromium (VI) removal capabilities than the untreated ones. The removal efficiency was found to be in the order (CARSC)> (CRSC)> (ARSC) > (RSC). The optimum pH was found to be between 1.0 and 2.0. The equilibrium data for the adsorption of chromium (VI) were analyzed in the light of Langmuir and Freundlich isotherm models.