While talks are on about filling landfills and segregating waste at the source, S. Rajendran, Associate Professor of Botany, Saraswathi Narayanan College in Madurai in Tamil Nadu has successfully moved a step further in an attempt to optimally use waste generated in the city, exemplifying that trash can be a source of revenue. Professor Rajendran cultivated mushrooms with the use of organic manure obtained from municipal solid waste.

This was a result of a project undertaken by him on ‘Feasibility study of technology for smoke-free briquettes’ with agricultural waste. Initially, he focussed on producing quality briquettes for the Department of Science and Technology-funded project. Later on, he switched to the cultivation of mushrooms after observing the high organic content in agricultural waste.

The organic substance is separated from the waste and oyster mushrooms are cultivated through solid-state fermentation technology. This is a process where the organic matter is seeded with mushroom spawns. The substrate is then left in a temperature-controlled room for 15 days to get the first yield of mushrooms. After the mushroom harvest, the fungal fermented substrate is used to make briquettes.

The professor soon branched out and applied the same technology to municipal waste. He first demonstrated the study in Paramakudi Municipality. Now, Rajendran regularly conducts free training programmes for entrepreneurs interested in mushroom cultivation and he has also developed healthy mushroom spawns. He has also submitted a proposal to the city corporation.

There is generally an aversion towards agricultural produce grown on municipal waste. The local body collects garbage from residences and commercial establishments and transports them to the dumping yard in Vellakal near Perungudi where the degradable waste is digested aerobically and composted to manure. The corporation has devised a solid waste management programme in accordance with the guidelines of the inter-ministerial task force established by the ministries of environment and urban development. The manure can be used to grow not only mushrooms but also other vegetables.