Bioremediation of Dye Effluent and Metal Contaminated Soil: Low-Cost Method for Environmental Clean Up By Microbes

Abstract

Dye and metal effluents pose severe environmental hazards. Bioremediation of these effluents and the contaminated soils have been widely attempted. The present study was carried out to decolorize the dye effluents, degrade the contaminants present in the eftluent, minimize the COD below standard limits and reduce heavy metal content in the metal contaminated soil by using biomass isolated from the contaminated samples. The dye effluent samples collected had a high COD of972 mg/L, pH 8.6 and highly objectionable color (990 Hazen Units}. The predominant indigenous organisms present in the samples were isolated and identified as Aspcrgilus niger, Asperg1Jus llavus and Bacillus sp. Slurry phase reactor was used to treat soil, up flow immobilized column reactor was used to treat both soil and effluent. The shaker flask trials gave maximum decolorization efficiency of 91 % and COD reduction of 84%. The reactor studies showed elevated efficiencies of 92.7% and 93% in decolorization and COD reduction initially. The soil treatment results showed that, the up flow immobilized column reactor can reduce the heavy metal content appreciably within 24 hours. Thus the present study can evolve as an efficient strategy to treat wastewater and also provide a better insight into the field of bioremediation.