Bioremediation of diesel oil in marine environment

Abstract

Natural gas emissions from oil spill ensue changes to microbial consortia in oceans which might cause ecotoxicological impacts on marine life. Gas flaring, a technique in the clean-up of oil spill, is a major source of greenhouse gas emission and possess high risk of fire hazard. It is of utmost importance to avoid flaring and resort to cleaner techniques such as bioremediation. The study focuses on bioremediation of marine oil spill by indigenous bacterial consortia using beeswax as a biostimulant which supplements the limiting nutrients such as nitrate and phosphate. The experimental study was conducted by adding diesel oil in marine water with beeswax for bioremediation. The vital parameters such as dissolved oxygen, pH, diesel range organics, total microbial count, nitrate and phosphate contents were measured at intervals of 5 days. The indigenous bacteria utilized oil as carbon source and beeswax as nutrient source for growth and metabolism. The results showed 87% removal of oil content in treatment sample while only 59% reduction was achieved in the corresponding control sample. Evaporation of oil results in formation of aerosols and black carbon which can lead to climate change. The study proves that bioremediation of marine oil spill is an environmentally benign clean-up technique for oil spill which can reduce carbon emission.