Scientists at Kerala Agricultural University have developed two microbial cultures that can replace cow dung in aerobic composting for large-scale management of solid waste.
The university’s Department of Agricultural Microbiology developed the microbial isolates including bacteria, fungi and actinomycetes from various sources like soil, degrading plant materials and cow dung.
Demonstration units set up at several apartments in the Thrissur Corporation and the ladies hostel on the main campus of the university have proved the efficacy of the technology.
“This is a response to the growing challenge of solid waste management in Kerala,” says P. Rajendran, Vice Chancellor.
“Urbanisation, changes in lifestyle and food habits and the decrease in availability of land have led to waste accumulation and a change in the composition of garbage. The repercussions of this are serious and unpredictable,” P. Rajendran said.
Dr. Rajenran said the composting method developed by the university would enable efficient conversion of solid waste into organic manure, making it the best option for large-scale composting plants.
Conventional composting employs cow dung as a source of microbial inoculum for degradation of waste. But cow dung has become a rare commodity, especially in urban areas, triggering the search for efficient microbial cultures as an alternative.
The research team carried out studies to evaluate the efficacy of microbes utilising cellulose, lignin, protein and starch degradation. Seven efficient isolates selected from the preliminary studies were further screened using vegetable waste.
Two of the isolates, Bacillus subtilis and Bacillus niabensis were found to be effective and completed the degradation of solid biodegradable waste within 17 days.
The technology was validated at the Communication Centre, Mannuthy, with vegetable waste collected from the market. The resultant compost was found to have a fine texture. When analysed for nutritional quality, it was found to have a pH of 7.4, moisture 25%, Carbon to Nitrogen ratio of 22 and nitrogen 1% – indicating its suitability as organic manure.
Dr. Rajendran advocates an integrated approach to bio-solid waste management, incorporating different methods to suit local conditions. “For independent households, biogas plants are the best, which generate energy for fuel, apart from giving slurry that can be used as good quality manure. For housing colonies and apartments, aerobic composting will be optimum. The compost from the unit may be used for organic terrace cultivation of vegetables,” he says.
Source:The Hindu April 17,2013