Bioremediation to treat sludge collected after Ennore spill

While removing the sludge collected at the RK Nagar beach in Ernavur may have been completed, the bioremediation of the sludge is currently underway. Sabitha Natraj, Chief Corporation Communication Manager for Indian Oil Corporation (IOC), said the organisation had previously used bioremediation for treatment of oil sludge. 

Detailing the process, she said, “The sludge, which is around 250 tonnes, has been removed to the bioremediation site at the Ennore Port. It is 2,000 square metres and 1.5 feet deep. We have used a bioinoculum with specialised nutrients. We have spread specialised sheets, then a layer of normal soil and the oil contaminated soil and sludge. The microbes were spread on this. These organisms will eat up the oil and leave the sand behind. The process will take three months and every month samples will be taken for further analysis,” she said. 

Dr Sultan Ahmed Ismail, soil biologist, said bioremediation is a process in which micro organisms act on hydrocarbons converting it into non-toxic substances. “The microbes will convert the oil into cake, leaving behind fluid on top. This fluid should be analysed before it is discarded. I do not know if the resultant cake will be tested for safety before incineration or if it will be recommended for some other use,” he said. 

The ecologist added that since the oil spill had drifted off to other parts of the shore, there should be constant checks to ascertain the impact on the environment. “Though it may not be visible to the naked eye, the areas where the spill has moved should be monitored. If the oil spill has reached the shores, there could be a possibility of groundwater contamination. It is the duty of the government to take samples, analyse and declare if the coastal drinking water is safe. Communication with the public is keenly required now,” added the Director of Ecoscience Research Foundation. 

The Environment Ministry is likely to issue a show cause notice to the Kamarajar Port (Ennore port) in Chennai for ‘mishandling’ the oil spill following a collision between two ships last month. Ministry sources said that the clearing of the oil is at an ‘advance’ stage and a team of Central Pollution Control Board (CPCB) also visited the port for monitoring the situation.