Bioremediation of heavy metals using biostimulation in laboratory bioreactor

Abstract

The present research study investigates bioremediation potential of biostimulated microbial culture isolated from heavy metals waste disposal contaminated site located at Bhayander (east), Mumbai, India. The physicochemical and microbial characterization including heavy metal contaminants have been studied at waste disposal site. The microorganisms adapted at heavy metal-contaminated environment were isolated, cultured, and biostimulated in minimal salt medium under aerobic conditions in a designed and developed laboratory bioreactor. Heavy metals such as Fe, Cu, and Cd at a selected concentration of 25, 50, and 100 μg/ml were taken in bioreactor wherein biostimulated microbial culture was added for bioremediation of heavy metals under aerobic conditions. The remediation of heavy metals was studied at an interval of 24 h for a period of 21 days. The biostimulated microbial consortium has been found effective for remediation of Cd, Cu, and Fe at higher concentration, i.e., 100 mg/l up to 98.5%, 99.6%, and 100%, respectively. Fe being a micronutrient was remediated completely compared to Cu and Cd. During the bioaccumulation of heavy metals by microorganisms, environmental parameters such as pH, total alkalinity, electronic conductivity, biological oxygen demand, chemical oxygen demand, etc. were monitored and assessed. The pilot scale study would be applicable to remediate heavy metals from waste disposal contaminated site to clean up the environment.