Neethi Nair, Nandini N
In the past few decades, the global focus has been on modernization through the indefinite exploitation of natural resources. Worldwide rapid industrialization, advancement in technology, uncontrolled population, and unplanned urbanization have resulted in a problem in the management of waste. Waste management was never a priority and it kept on accumulating for decades. The waste in landfills has been releasing toxic gases, polluting groundwater, causing loss of biodiversity, etc., and have impacted the lives of people in surrounding areas. To mitigate the environmental impacts and bring the resources back to a circular economy, a novel and sustainable approach is landfill biomining. In this study, the legacy waste of 21 lakh tonnes from Mandur landfill is excavated, and an effective microbial consortium is sprayed at regular intervals. The effective microbial consortium used for stabilization consisted predominantly of aerobic and facultative anaerobic microorganisms, including cellulolytic bacteria, lignolytic fungi, and heterotrophic decomposers commonly employed in organic waste stabilization. These microbial groups facilitate the breakdown of residual organic matter through enzymatic degradation of cellulose, hemicellulose, and other biodegradable compounds, thereby accelerating waste stabilization and volume reduction. The sun-dried waste is segregated and screened. Recovered combustibles constitute approximately 25% of the excavated waste, with a calorific value of 5319 kcal/kg can be used for incineration or co-combustion in the cement industry while recyclables such as metals, wires (1%), etc., can be recycled. The inert such as stones recovered can be used for infrastructure or paving roads and the soil-like fraction (36%) obtained is unsuitable for direct use as fertilizer due to nutrient deficiencies but can be used as a soil conditioner with appropriate nutrient enrichment or for landscaping and landfill reclamation purposes. The paper also discusses the energy potential of combustibles and the technical feasibility of setting up incineration technology.