Fate of volatile organic compounds and pesticides in composted municipal solid waste.

摘要

The present study was undertaken to evaluate the fate of four volatile organic chemicals, VOCs, (benzene, carbon tetrachloride, dichlorobenzene, and xylene) and two pesticides (Captan and Lindane) added to simulated municipal solid waste, MSW. Volatile organic chemicals were added at three concentrations while pesticides were tested at a single concentration. All of the treatments were replicated three times and composted in 200 litre aerated static pile composters. The composters aerated the feedstock at 1.12-1.68 m3/hr, collected volatile organic chemicals from the exiting air stream and leachate was also collected. Feedstock was selected to be representative of MSW after the majority of recyclable metal and glass had been removed and was spikedwith organic chemicals known to commonly occur in MSW. The majority of VOCs present in the feedstock volatilized in the initial 48 hours of composting. Concentrations of VOCs were below detection limits after one week of composting in both the leachateand compost. Thus, while aerated pile composting is effective in removing VOCs from the feedstock, the exiting air stream needs to be monitored for approximately one week and possibly treated to meet environmental quality standards. Aerobic composting reduced the initial concentrations of 275 mg/kg each of Captan and Lindane to final concentrations of 53.8 and 158.9 mg/kg, respectively, after five weeks of composting. This corresponded to half lives of 1.5 and four weeks during composting for Captan andLindane respectively. All concentrations of both pesticides were below detection limits in all samples of air, condensate and leachate, indicating that none of the pesticides were volatilized and all were retained by the MSW until they biodegraded.