For the students and staff of this college, the reality of Puducherry’s waste problem is something that strikes them every day.
Located in Ramanathapuram village, Villianur Commune, the Dr. S. J. S Paul Memorial College of Engineering and Technology in Puducherry is not just close to the Kurumbapet landfill, but to the Ponlait (Pondicherry Co-operative Milk Producers Union) dairy plant as well, which sits just in front of the dumping yard.
In a bid to find a solution to the dumping of waste, the Centre for Alternative and Renewable Energy Sources in the college has designed a co-digestion pilot project which uses the organic fraction of municipal solid waste and dairy waste effluent for enhanced energy (carbon) extraction.
The project has been headed by P.K. Pratapchandran, Principal of the college and head of the centre, C. Vijaya Raghavan, Head, Department of Civil Engineering, and Dhanakantharaj, Assistant Professor, who has specialised in environmental engineering, and students Vikneshwar N., Suganya S., Arjun K.T. and Binish Babu.
For the project, they sourced segregated (organic) municipal solid waste from the Puducherry markets, and samples of the dairy waste effluents from the neighbouring Ponlait dairy plant. Preliminary tests were conducted in a laboratory, before being scaled up to the pilot project.
“We pass by the dumping yard and the Ponlait dairy unit on our way to college, and are aware of the problems of untreated waste. We also see waste being dumped indiscriminately on the roadside, which can lead to harmful diseases,” says Mr. Arjun.
“We designed a co-digestion unit because treating solid waste requires water. This way, we can substitute water with dairy effluent. Besides, dairy effluent if let to percolate into the ground or let to reach the sea is dangerous for the environment,” says Mr. Pratapchandran, who has in the past designed a similar co-digestion project using distillery effluent.
The unit consists of a polypropylene drum of 50 litres capacity, and is connected to a single burner stove. The unit can produce biogas within 20 days of filling the drum, says Mr. Arjun. The sludge from the unit, which is treated using coconut tree bark, can be used for irrigation, and as fertilizer, and for non-potable uses, says Mr. Arjun.
After conducting further tests on capacity and material of the unit to increase efficiency in energy generation, the team wants to approach Ponlait about the installation of an economically-viable demo model within the Ponlait campus.
“The Ponlait dairy plant has a capacity of producing 1 lakh litre of milk daily and releases a sizeable quantity of effluent. A co-digestion plant ensures the safe disposal of these wastes,” says Mr. Pratapchandran.
Mr. Pratapchandran and Mr. Raghavan will present the co-digestion pilot project at Sardinia 2015, an international conference on waste management to be held in Italy later this year.
