Characterization of Red Mud as a Construction Material Using Bioremediation

Abstract

Globally 120 million tonnes of red mud/bauxite residue is generated annually posing a very serious and alarming environmental problem. The most important barrier to remediation, re-use and long term sustainability of bauxite residue management is its high alkalinity. The main objective of the study pertains to stabilize and neutralize red mud concerning strength and stability factors viz. reclamation, wind erosion, dust control, and other harmful effects in its stacking areas. The neutralization of red mud was achieved by five different strains of microbes. Then morphological, physical and geotechnical properties of neutralized red mud are studied. Due to organic acid production by the microbes there is a noticeable change in the physical properties of the residue. Red mud is also stabilized using biopolymer Xanthan gum (1%, 2% and 3%), and a noticeable increase in unconfined compressive strength was observed for the stabilized red mud. The effect of drying and exposition to the natural environment was also studied. The results of present study will help in effective utilization of the red mud.