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The trace metal content of municipal solid waste (MSW) compost affects the quality and potential end uses of the finished product. The impact of typical contaminants found in the organic fraction of MSW on the trace metal content of compost was investigated. Contaminants including alkaline batteries, galvanized nails, zinc-plated screws, copper wires, and electronic cables were exposed to a thermophilic composting process for three weeks. The increase in trace metal content in the compost product was measured at the end of the composting process. The results showed that low-quality alkaline batteries, galvanized nails, zinc-plated nails, and copper wires had a significant impact on the zinc, copper, arsenic, lead, and cobalt contents of compost. Copper wires showed the highest impact on copper content, which was 52% of the Canadian Council of Ministers of the Environment (CCME) Category A limit in the final compost. Galvanized nails contributed to final levels of zinc reaching 30% of the CCME Category A l...

A concern regarding MSW compost quality is the trace metal content. A study was initiated to assess the impact of various metal contaminants on compost quality. One critical step in the study was to estimate metal transfer during composting, which was achieved by measuring the corrosion rate of different contaminants during the high rate composting stage for 3 weeks using alfalfa hay and straw as composting substrate. A corrosion quantification technique, weight loss/gain of metal specimens, was employed to estimate metal release into composting substrate. Among the 7 types of contaminants, stainless steel screws, brass screws, and light bulb aluminum alloy thread contacts showed little weight changes. This suggests minimum concerns for these materials in terms of metal release during composting. The highest metal release per unit area was from light bulb foot contacts, which was 3.66 × 10−3 g cm−2, while galvanized steel nails and zinc plated screw had a metal release rate in the range of 1.5 to 1.9 × 10...