Field studies on monitoring the marine oil spill bioremediation site in Chennai

Oil spills have become a threat to the ecosystem by releasing the petroleum hydrocarbons and gained substantial public concern in the Chennai coast. This study assesses the effectiveness of bioremediation and its impact on the environment due to remedial operations in the site. Soil and water samples were collected from the bio remediation site at regular intervals of the pit from the topsoil and 20 cm below the ground level from June 2017 to Nov 2019. The average TPH concentration present in the bottom and top soil of bioremediation pit were vary in the range of 21,238.4–46,600 mg/kg and 17577–26910 mg/kg. Central Pollution Control Board (CPCB) allowable limit for TPH concentration present in the soil should be 5000 mg/kg. We have also observed that the mixing was not uniform in the pit and major amount of oil has been penetrated deep inside the soil. Results on gravimetric analysis showed that there was still a large amount of untreated long-chain hydrocarbons are there in the pit. From the results, we can conclude that nC30-nC40 and lower carbon range alkane intermediates have to be treated with additional treatment like thermal smoldering and pyrolysis.