Biodegradation of hexavalent chromium, oil and grease in paper mill effluent using Micrococcus luteus and Bacillus aquimaris isolated from soil

Waste water released from various industries is a major source of pollution in day to day activities. Among the various industries present, paper mill industry is categorized as one of the major cause of pollution to the environment. The problems associated with pulp and paper mill effluent are of giving out waste water with a variable pH value, high level of BOD, COD, suspended solids, absorbable halides, heavy metals etc. Among the different toxic compounds present in the paper mill effluent, chromium is present in high levels. Hexavalent chromium (Cr (VI)) is considered to be highly toxic, carcinogenic, and mutagenic to living organisms. Oil and grease present in paper mill effluents are producing off foul odours in the surrounding environment, blocking sewer lines, causing ill effects to the soil fauna, flora and microorganisms, soil physico-chemical properties etc. Physico-chemical methods do not provide effective solutions in elimination of heavy metals from the effluent. Hence in this study efforts were made to degrade the heavy metals, oil and grease using bacteria isolated from soil. Micrococcus luteus and Bacillus aquimaris effectively removed the hexavalent chromium, oil and grease after 96 hours by degradation activity.