Population expansion in Sri Lankan cities coupled with changing consumption patterns mean that volumes of solid waste are fast becoming an environment hazard. Channeling this biodegradable waste into compost will reduce environmental pollution.
But a study conducted by IWMI in 2013 found that in Sri Lanka, the nutrient content of compost made from municipal solid waste is low in essential nutrients.
IWMI, working with the Central Environment Authority (CEA) and the Kurunegala Municipal Council (KMC), introduced a pilot project turning biodegradable garbage into nutrient-rich organic compost, which was set up at the KMC composting station in Kurunegala.
The project follows an agreement signed between IWMI, the CEA and the KMC in June, 2014, to compress the compost into tiny pellets that make it easier to handle, store and transport, and to also conduct tests to improve the quality of the compost by adding local nutrients like rock phosphate, fecal sludge, and paddy husk.
Domestic and commercial solid waste brought by trucks to the KMC compost plant in Kurunegala is sorted into biodegradable and non- biodegradable waste. Fecal sludge is also transported to the septage treatment plant, using septic trucks.
Organic waste is made into piles. Recyclable inorganic material is sold and the non-recyclables are sent to landfill. Organic material is made into different piles and turned over periodically for about two months to aerate the compost and increase decomposition.
The compost is then bagged, weighed and dispatched, ready for use.
The IWMI study, based in the KMC compost plant, sorts municipal solid waste into several piles of organic waste to which dried fecal sludge is added in a process known as co-composting. Different raw material including saw dust, Eppawala Rock Phosphate (ERP), rice husk and fecal sludge are then added in varying proportions to develop value- added organic fertilizer.
The compost is now ready for turning into pellets before which moisture levels are monitored to ensure that the right consistency is maintained.
The compost is fed into the machine that compresses it into pellets.
Compost pellets vary in size from between 5 to 20 mm.
The compost is used to grow vegetables – tomatoes, capsicum, chilies, long beans, turnips and ribbed gourd – in the KMC garden.
The IWMI greenhouse grows cabbage and spinach using different compositions of compost and pellets.
IWMI is conducting germination tests on different seed varieties which will be grown in varying combinations of nutrients to test their effectiveness in growing diverse crops.
Addressing the challenge of solid waste and fecal sludge co-composting by turning it into an asset is an innovative strategy that IWMI has introduced successfully in several other Asian and African cities.
