Chemolytic Analysis of Organic Matter during Aerobic and Anaerobic Treatment of Municipal Solid Waste
- Martin Pichler and
- Ingrid Kögel-Knabner *
The aim of our study was to elucidate the mineralization, transformation, and stabilizafion of organic matter (OM) of municipal solid waste (MSW) during four types of aerobic and anaerobic treatment with respect to methane and leachate emissions of treated waste in the landfill. The treatments were (i) windrow composting with and (ii) without pressure aeration, (iii) alternating aerobic and anaerobic treatment in bioreactors, and (iv) anaerobic digestion in a solid-state fermentation system. The composition of OM was assessed using the following geochemical methods: two-step acid hydrolysis and colorimetric detection of carbohydrates, colorimetric detection of proteins, CuO oxidation analysis of lignin, and gravimetric determination of lipids. Organic matter losses between 53 and 75% were achieved by all treatments. Carbohydrates are the most relevant compound class for landfill emissions and exhibited the highest mass losses (71 to 88%) during treatment. Hence, a substantial reduction of landfill emission potential was assumed. Protein and lipid losses were lower due to microbial resynthesis and recalcitrance. Lignin was degraded only to a minor extent and experienced no important structural changes. In summary, during the degradation of MSW, the OM composition shifted from easily degradable to recalcitrant compounds, indicating stabilization of MSW. Compared with humified OM of natural topsoil horizons, treated MSW showed slightly higher cellulose and lipid contents. Pressure aeration was essential for achieving optimal degradation rates during aerobic composting. Anaerobic digestion combines high degradation rates and possible energy recovery from methane.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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