For the first time, such an integrated approach of bio-remediating oil contamination in water bodies (effluent pits) has been tried out in OIL, the PSU said in a statement.
This has made the environment of the pits conducive for the growth of algae and associated aquatic flora and fauna, the PSU claimed.
The first of its kind 'Pilot Scale Bio-Remediation' initiative by OIL's newly established Biotechnology Section was started in August last year to lower the oil content in DEPs to less than 10 parts per million (ppm) within six months, it said.
The oil content has been brought down to a level of 10 ppm from original level of 2,00,000 ppm. The pilot study was carried at drilling effluent pits at Amgurigaon in Dibrugarh district.
The technology used in the pilot scale study involves augmentation of the rate of bio-degradation of floating oil in the pits with the help of micro-organisms (bacteria) which are naturally occurring in the environment along with incorporation of bacterial species capable of rapid degradation of oil contamination, the release said.
Measurement of the oil content in effluent water, using internationally accepted standard protocols and advanced Gas Chromatographic Analysis of various fractions of crude oil corroborate the success of integrated In-Situ bio-remediation/ bio-augmentation technology used in the project.
Results obtained from bio-assay for determining the toxicity of the treated effluent (water) from the pits using Fish Survivability Test have been found to conform to the Standards for Discharge of Environmental Pollutants (The Environment (Protection) Rules, 1986) of Central Pollution Control Board (CPCB).