Bacteria that turns contaminated oil into compost
New Delhi   23-Feb-2017


Dr.SSV Ramakumar, Director(R&D),IndianOil

Even before Dr SSV Ramakumar could submit the joining report as the director (research and development) for Indian Oil Corp (IOC), he received a call from the petroleum ministry, and was handed a herculean task. “The first day at office started with a bang,” said Ramakumar, who was earlier the executive director (research and development) at the state-run oil marketing firm.

The call came a day after an oil spill occurred in the early hours on January 28 when two ships – MT BW Maple carrying liquefied petroleum gas and MT Dawn Kanchipuram carrying oil lubricants – collided near Kamarajar port in north Chennai.

The directive was to ensure environment-friendly disposal of spilled oil – which at present is believed to have spread up to Mahabalipuram, 72 km away from the spill site – that was spread across the shore. Within hours of getting the call, IOC scientists were at the site to assess the situation and it was found that a patented bio-remediation process used by IOC was ideal for such a situation. Oil at Chennai site was collected manually as skimmers, which zaps the oil mechanically through suction, rendered ineffective.

Incineration or bio-remediation

The choice to dispose the contaminated oil was between incineration and bio-remediation. Since the level of contamination was high, the option of distillation to recover virgin oil was not considered as the cost-heavy process would not have been apt.

Incineration means burning the oil, which would have meant a lot of energy is put in which would have not only been detrimental to the environment on the top of the spill which had affected flora and fauna along coastline but also would have emitted a lot of oxides of carbons, sulphur and nitrogen in the open environment. Under bio-remediation, however, contaminated oil is treated through eco-friendly and cost effective method, which turns it into natural compost.

Around 2002-03, IOC developed this bio-based remediation process to treat sludge – residue left after refining petroleum products – at its refineries and marketing sites. Since then, it has obtained at least three patents in the US and two in India which are still in force.

“Since these patents are not very old, these will run for a long time as of now,” said Ramakumar, as patents are granted for 20 years.

The company has identified five strains of bacteria which are grown in a bioreactor under controlled conditions at the company's R&D facility in Faridabad.

The bacteria adsorbed on agricultural residue are applied to oil sludge mixed with soil along with optimized nutrient. The operating procedure for the process is also standardised and patented.

Getting a patent for technology based on bacterial strains is unique. “For patenting a microbe-based technology, first we have to deposit the strains in a repository recognised by World Intellectual Property Organisation as an International Depository Authority under the Budapest Treaty. It is designated depository of National Biodiversity Authority as well as of Indian Patent Office. These microbes are stored in lyophilized form and we get a registration certificate,” said Ramakumar.

The process

The bioremediation process is applicable for onshore spillage as contaminated oil is required to be spread over soil in an open cordoned area.

Normally, a pit with a depth on one foot is created and is first covered with plastic sheet which is required to arrest the permeation of the oil into the ground soil/water, and some soil is put on top of the sheet followed by contaminated oil or sludge, and then the bio-inoculum is spread along with nutrients dissolved in water.

In the case of Chennai, a 2,000 square metre big pit has been created at a cordoned area inside the Kamrajar port.

The day Ramakumar got the call, around 600 kg – 500 kg of bio-inoculum and rest nutrients – were transported to Chennai overnight from Faridabad.

These bacteria have ability to eat up the oil and convert it to biomass, small amount of carbon dioxide and water through their metabolic activity.