At current estimates, over 1,700 tonnes of waste is generated in Pune of which around 52 to 55 per cent is wet waste. When such wet food waste is segregated and removed separately at source, the rest of the inorganic waste like plastic, metal, paper, rags, etc. also can be scientifically processed and effectively recycled. This ensures minimisation of land fill and freeing up urban land for more productive purposes.
At present, the Pune Municipal Corporation (PMC) has combined an integrated approach with a decentralised waste management strategy. It has 25 decentralised bio-methane plants that produce 600 kw of electricity and compost, the 300 tpd plant by Noble Exchange Environment Solutions Pvt Ltd (NEX) that converts food waste to bio-CNG, a 300 tpb (total plumbum) vermi-compost and compost projects by Ajinkya Biofert and Disha, and the Rochem Separation Systems that process mixed waste to produce 300 tpd producing refuse derived fuel (RDF).
That said, Pune’s DBOT project by NEX, which converts foodwaste into valuable bio fuel, has already started producing 45 tpd of bio-CNG and 150 tonnes of organic manure at its Talegaon plant, based on the anaerobic digestion system. At full capacity, it can process 300 tonnes of waste, making it the largest biogas plant in India.
PMC’s responsibility was to ensure collection of food waste from bulk producers such as hotels and markets and to provide 15,000 sq ft of space for the first-stage sorting, segregation and making slurry. The actual processing is done at the 5-acre Talegaon plant owned by NEX. The fuel generated from this plant will power buses managed by the Pune Mahanagar Parivahan Mahamandal Ltd (PMPML). The fuel generated is claimed to be cleaner and more cost effective than CNG.
A few unique features of the environmentally-efficient NEX waste processing plant include odourless and noiseless operation with zero discharge, which is essentially based on the anaerobic digestion system with water-based cleaning, scrubbing, and compression system that converts the organic waste slurry into compressed biogas (CBG).
The plant helps in better digestion and circulation of the slurry inside the digester and avoids settling of the solids inside the digester and is designed to handle all biodegradable waste. By-products generated from the process will be organic fertilizers that replace chemical fertilizers for farming. Compressed biogas (CBG) produced at the processing plant will be marketed to institutional clients to replace conventional energy – LPG, diesel, etc.
Managing dry waste
PMC—in association with Adar Poonawalla Clean City—is also taking care of 30 per cent of the city’s street dry road waste. The Serum Institute of India Ltd has already purchased 111 machines, which is a combination of ‘Glutton’ suction machines imported from Belgium; a fleet of customised Tata trucks mounted with even bigger vacuum machines sourced from Holland; and Johnston (from Britain) sweepers to manage dry road waste. Interestingly, the trucks have waste segregation machinery fitted within. As of now, the company has covered 30 per cent of the city streets and has a target to cover 300 km in next six months.