Effect of ageing on waste characteristics excavated from an Indian dumpsite and its potential valorisation.

• Effect of ageing on different physicochemical characteristics of the excavated waste. • Fine fraction (<4 mm) accounted highest ∼45%, while metal content was <1%. • Assessment for the valorisation of the recovered waste streams. This paper assesses the effect of ageing on physicochemical characteristics of excavated municipal solid waste from Mulund dumpsite in Mumbai, India. Based on disposal year, waste was excavated from different zones in the dumpsite. The excavated waste was screened into five different size categories and further sorted into different streams. Physicochemical characteristics, i.e., pH, bulk density, ultimate and proximate analysis, calorific value and heavy metal concentration of excavated waste were also determined. The results indicate a change in the characteristics and composition of waste with age. The particle size distribution of waste revealed that waste above 80 mm was mostly plastic and textile, whereas <4 mm (fine fraction) composed of soil-like material. Above 80 mm fraction shows a decreasing trend with age and depth, suggesting particle size reduction with time. Parameters like volatile matter, total and organic carbon and calorific value of excavated waste also reduced with the age. A significant portion of waste was fine fraction (∼45%) emphasising on its valorisation for success of landfill mining. Furthermore, metal content in the dumpsite was <1%. The findings from this study can be used to reclaim dumpsites and suggest possible valorisation routes for excavated waste in developing countries like India. [ABSTRACT FROM AUTHOR]