Screening of natural waste products for the removal of Cr (VI) ions from industrial effluents

Abstract

The present study was performed to explore the possibility of using biowaste materials namely paddy straw, coconut palm fibre, corn husk and pineapple crown top as biosorbents of chromium (VI) ions in aqueous solution. The batch experiments were carried out to investigate the effect of the significant process parameters such as initial <i style="">p</i>H, contact time, adsorbent dosage and the initial Cr (VI) concentration. The maximum adsorption of Cr (VI) on biowaste material was obtained at an initial <i style="">p</i>H value of 2. The removal rate of Cr (VI) increases with the increase of the adsorption time. However, it remains constant after an equilibrium time of 240min. The removal of Cr (VI) ions increased with the increase in biosorbent concentration. The increase in initial concentration of Cr (VI) led to increase in the per cent removal of Cr (VI). In order to demonstrate the practical application of the biosorption process, biosorption of Cr (VI) was carried out in a packed bed adsorption column system using screened biowaste material. The electroplating wastewater was treated until the Cr (VI) concentrations reached the EPA standards and the concentrations of the pollutants were found to decrease after the treatment using glass column.