PACKED BED REACTOR SYSTEM STUDY ON THE BIOSORPTION OF Cr(VI) FROM AQUEOUS SOLUTION USING CORN COB POWDER

Thesis Abstract

The current method used in the treatment of Cr(VI) uses biosorbents that are expensive hence the need for cheaper available biosorbent. In this study,potential use of corn cob powder biomass, as a bioremediation agent for the removal of Cr(VI) was investigated in a packed bed column bioreactor. The effects of the operating parameters such as influent Cr(VI) concentration, pH, biomass concentration, flow rate and temperature, on the Cr(VI) removal were investigated in the continuous system using a packed-bed reactor. Percentage removal curves were obtained for different flow rate, pH, temperature, biomass concentration and initial concentration of Cr(VI). It was found that the adsorption of Cr(VI) to the biomass was strongly dependent on these parameters, as expected. In particular, the influent pH and temperature were most significantly affected leading toa high percentage removal of Cr(VI); a decrease in the influent pH of 2, and an increase in the temperature up to 70°C enhanced the Cr(VI) reduction in the column significantly.

Both Langmuir and Freundlich adsorption isotherms fitted reasonably well with

the data and showed high correlation coefficient (R2) values of 0.993 and 0.985 respectively. These results show that, the adsorbent can be used as a low cost alternative in biosorption of wastewaters containing lowerconcentrations of Cr(VI).Finally, the potential of the column packed with corncobbiomass for Cr(VI) detoxification has been found to be a good biosorbent in removal of Cr(VI) from aqueous solutions and also in the treatment of Cr(VI) containing industrial waste.