Oilzapper: eliminate crude oil spills, manage oily sludge

In the year 1997, TERI initiated the research on crude oil and oil sludge degrading bacterial consortium.

TERI developed  Oilzapper was produced in bulk and immobilized on to a carrier material (organic  powder material). Carrier based Oilzapper was used for clean up of crude oil spills and treatment of oily sludge.

More than 40,000 tonnes of oily sludge/oil contaminated soil and drill cuttings have been treated at various locations. More than 30,000 tonnes of oily sludge/oil contaminated soil is under treatment at different locations in India and the Middle East countries.

With the application of Oilzapper, crude oil contaminated agricultural lands were cleaned up in the north-eastern and western parts of India.

Problem

Oil spills are a major menace to the environment as they severely damage the surrounding ecosystems. Since crude oil is lighter than water, it floats on the sea surface and results in a swift-spreading fire.  Oil spills can also take place on the land as a result of leakage from terrestrial pipelines and pilferage activities. Oil spills on land pose a three-fold menace: fire hazards, groundwater pollution due to percolation, and air pollution due to evaporation. Apart from the accidental spills of crude oil, oily sludge – hydrocarbon waste generated in huge quantities by oil refineries – also creates environment pollution.

Oilzapper

This bacterial consortium was developed by mixing five bacterial strains, which could degrade aliphatic, aromatic, asphaltene, and NSO (nitrogen, sulphur, and oxygen compounds) fractions of crude oil and oily sludge. Crude oil and oily sludge degrading efficiency of the developed bacterial consortium was tested under laboratory conditions and field conditions.

A feasibility study on the bioremediation of soil contaminated with crude oil/oily sludge was carried out at the Mathura oil refinery (India). The feasibility study was carried out with six different treatments in a 25 square metre land area contaminated with crude oil/oily sludge prior to full scale bioremediation. The indigenous crude oil/oily sludge degrading bacterial population was only 104 c fu/g soil in the feasibility study. Of the six treatments, the application of bacterial consortium and nutrients gave maximum response, which resulted in 48.5% biodegradation of TPH (total petroleum hydrocarbons) in four months as compared to only 17% biodegradation of TPH in soil treated with nutrients alone. Based on the feasibility study,  the treatment consisting of the application of bacterial consortium and nutrients was selected for full-scale bioremediation.

Way forward

The success of Oilzapper and Oilivorous-S can be gauged by the tremendous response received from various oil refineries. At present, TERI and IOC R&D centre are working on the bioremediation of oil spill sites and the treatment of oily sludge at various oil refineries and oil exploration sites.

SITE PREPARATION

A microbial consortium was developed from five bacterial isolates. These isolates were obtained from hydrocarbon-contaminated sites using enrichment methods. The microbial consortium developed was immobilized with a suitable carrier material, namely powdered corncob, which is an environment-friendly, biodegradable product. The survivability of the consortium in the immobilized condition was determined and was found to be 3 months at ambient temperatures. The immobilized culture was put into sterile polythene bags and sealed aseptically and transported to the place of requirement. This immobilized bacterial consortium was named Oilzapper.

The site was tilled thoroughly to mix the oily sludge uniformly with the soil and oilzapper applied onto it. The land was tilled again and watered to maintain proper aeration and moisture levels. The land was tilled at regular intervals to facilitate faster degradation.

The problem of heterogenous distribution of the oily sludge was solved by extensive tilling prior to the application of the oilzapper. Another microbial-based product Oilivorous-S was jointly developed by TERI and IOC's R&D centre in Faridabad for treatment of oily sludge.

The end-users of Oilzapper and Oilivorous-S technologies are

 Indian Oil Corporation Ltd, India

 Bharat Petroleum Corporation Ltd, India 

 Hindustan Petroleum Corporation Ltd, India

 Oil and Natural Gas Corporation Ltd, India

 Oil India Ltd, India

 Indian Petrochemicals Corporation Ltd, India

 Reliance Industries Ltd, India

 Abu Dhabi National Oil Company, Abu Dhabi

 Kuwait Oil Company, Kuwait