Project Materials

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

ABSTRACT

The existing approach for treating Cr(VI) requires expensive biosorbents, necessitating the employment of a more affordable biosorbent. In this study, we explored the possible use of maize cob powder biomass as a bioremediation agent for Cr(VI) removal in a packed bed column bioreactor. The effects of operating factors such as influent Cr(VI) content, pH, biomass concentration, flow rate, and temperature on Cr(VI) removal were studied in a continuous system with a packed-bed reactor. Percentage removal curves were obtained for various flow rates, pH, temperature, biomass concentrations, and Cr(VI) starting concentrations. The adsorption of Cr(VI) to biomass was found to be strongly dependent on these parameters, as predicted. In particular, the influent pH and temperature were most strongly affected resulting 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 increased the Cr(VI) reduction in the column significantly.

Both the Langmuir and Freundlich adsorption isotherms suit reasonably well with

The data had high correlation coefficient (R2) values of 0.993 and 0.985, respectively. These findings demonstrate that the adsorbent can be employed as a low-cost alternative in the biosorption of wastewaters with lower levels of Cr(VI).

Finally, the column packed with corncobbiomass has been shown to be a suitable biosorbent for the removal of Cr(VI) from aqueous solutions as well as the treatment of Cr(VI)-containing industrial waste.

Chapter one

INTRODUCTION

1.1 Background of the Study

Over the last three decades, there has been a growing global concern about the health effects of environmental pollution. According to the World Health Organisation (WHO), nearly a quarter of all diseases affecting humans today are caused by extended exposure to environmental pollution.

Heavy metal pollution is one of the most important environmental risks caused by numerous industrial discharges (Wang and Chen, 2009).

Many industrial processes emit hexavalent chromium Cr (VI) into the environment, including leather tanning, chrome plating, stainless steel welding, pigment manufacture, and nuclear weapon production (Gonzalez et al., 2003).

Chromium exists in two oxidation states Cr(III) and Cr(VI), and the most hazardous form is Cr(VI), which has been implicated in cause of liver damage, pulmonary congestion and oedema (Babu and Gupta, 2008; Raji and Anirudhan, 1998).

Pollution of water due to the presence of specific heavy metal ions is a serious socio-environmental issue caused by industrial wastewater discharge.