An environmental protection concern regarding municipal solid waste (MSW) compost quality is the trace metal content. This research investigated the effect of a composting environment on the corrosion of typical metal contaminants found in the organic fraction of MSW. A synthetic feedstock, created to have a low trace metal content, was used in the study. Selected contaminants were exposed to either a low pH or a high pH feedstock for a three-week thermophilic composting process in 1 m3 reactors. The weight loss of each contaminant was determined using a corrosion weight loss method. The characterization of corrosion products and the corrosion condition was achieved by applying Scanning Electron Microscope (SEM-EDX), X-ray Diffractometer (XRD), Gas Chromatography (GC) and lon-chromatography (IC) techniques. Galvanized nails and Zn-plated nails were selected since they both contain trace metal zinc on the base steel. Stainless steel flat washers were selected because of the chromium content. Copper wires and brass screws were selected because of the high copper content. Light bulb tails were selected because of the tin and lead content of the foot contact. The metal composition of each contaminant was determined through SEM-EDX analysis. All the contaminants showed higher weight losses in the low pH environment, which suggested the corrosion rate was accelerated by the more acidic composting environment. The high mass transfer rate of zinc from the galvanized nails and Zn-plated screws suggested that they might be the main contributors to the zinc content in MSW composts. Low amounts of trace metals were transferred from the stainless steel flat washers and light bulb tail contacts.
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