Molecular Characterization of the Organic Fraction of Municipal Solid Waste and Compositional Evolution during Oxidative Processes Assessed by HR-MAS ¹³C NMR Spectroscopy

Abstract

The use of high-resolution magic angle spinning (HR-MAS) 13C NMR spectroscopy is proposed here as an innovative and non-destructive approach to investigate the chemical composition of the organic fraction of municipal solid waste (OFMSW) and for monitoring the evolution of their composition during the oxidative iron-based Fenton treatment to which the initial matrix is subjected. The high quality and the good resolution of the 13C HR-MAS NMR spectra allowed an accurate assignment and quantification of the various types of carbon present in the analyzed organic matrix. Moreover, the HR-MAS has also shown its effectiveness in monitoring the different oxidative processes to which the same initially organic matrix has been subjected. The results obtained from the HR-MAS spectra on the collected samples during the different oxidative experiments, indicate that Fenton treatment is able to modify the percentage of the different types of carbons as a function of the concentrations of both Fenton reactants, H2O2 and Fe2+ salt, and of the oxidative process time.

Keywords

• NMR spectroscopy
• high-resolution magic angle spinning (HR-MAS)
• organic materials
• OFMSW composition
• oxidative Fenton process
• monitoring oxidative treatments