Physicochemical and FTIR spectroscopic analysis of fine fraction from a municipal solid waste dumpsite for potential reclamation of materials

Abstract

Improper municipal solid waste management in the past has landed most of this waste in open dumps of India. This dumped waste has a negative effect on the environment and human health and needs to be reclaimed either for material/energy recovery or to create space for future waste management. Since nearly half of the waste in dumpsites can be classified as fine fraction, in-depth knowledge of its characteristics is required to reclaim these dumpsites successfully. In this study, we characterize fine fraction, <4 mm, aged 1–10 years old, obtained from Mulund dumpsite in Mumbai, using physicochemical and spectroscopic analysis. The study also highlights different valorization routes to reclaim the fine fraction. The fine fraction was ~45% in the dumpsite and increased with the age of the waste. Visual inspection revealed that fine fraction older than five years was relatively homogeneous compared with younger fine fraction. Furthermore, pH (7.4–7.8) and electrical conductivity (0.70–1.92 mS cm⁻¹) of the fine fraction met the Indian MSW compost standards; however, heavy metal levels were higher than the proposed standards. The fine fraction also had a high concentration of metals like aluminium (11 g kg⁻¹) and iron (78 g kg⁻¹), indicating metal recovery potential. Furthermore, Fourier Transform Infrared Spectroscopy results show that the fine fraction had dominant inorganic peaks and became relatively homogeneous with age. The study proposes fine fraction use as a secondary resource; however, some prior treatment would be required based on the application.