Solid-state 13C NMR spectroscopic, chemolytic and biological assessment of pretreated municipal solid waste

In Central Europe, composting and anaerobic digestion of municipal solid waste (MSW) is used as pretreatment before landfilling to reduce landfill emissions. MSW samples were analyzed before, during, and after pretreatment to assess the stability of the organic matter. Chemolytic, nuclear magnetic resonance (NMR) spectroscopic, and respiration parameters were correlated to evaluate a substitution of the time-consuming respiration analysis by chemical parameters. 13C cross polarization magic angle spinning (CPMAS) NMR spectroscopy showed a preferential biodegradation of O-alkyl carbon (carbohydrates) and a selective accumulation of plastics during all pretreatments, confirming findings from chemolytic analyses. Principal component analysis exhibited a strong association between the respiration rate, the carbohydrate content, and the O-alkyl C content, corroborating that carbohydrates are the most important compounds of MSW with regard to the emission potential. Rank correlation (Spearman) also showed strong relationships between the respiration rate and the content of carbohydrates (r = 0.75) and of O-alkyl C (r = 0.72).