Heavy metal emission factors for municipal solid waste incinerators

• Main Authors: Jen, Chuan-Hsiung, 任傳雄
• Other Authors: Chang Moo Been
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/73202974492765903314

碩士 === 國立中央大學 === 環境工程學系 === 85 === Abstract The practice of separation and recycling of waste for reuse does not prevail in Taiwan, so heavy metals jam into municipal solid waste (MSW) incinerators. Although the mass and volume can be effectively reduced by incineration, heavy metals may present in the form of fly ash or vapor in flue gas at the same time. Emissions of heavy metals may cause great impacts on human health and environment and need to be addressed. Two MSW incinerators (designated as Plant A and Plant B) in northern Taiwan were selected for conducting stack sampling and determination of the multiple metals emissions. Heavy metals examined in this study include zinc, lead, cadmium, chromium, copper and mercury. Isokinetic sampling was typically performed for 3~4 hours after the leak-check had been completed. The samples were then analyzed by atomic absorption spectrometry after proper digestion procedure. Preliminary results indicated that the average removal efficiency of particulate was about 99.95%, and the average removal efficiency of heavy metals could reach 99% or higher (except for Hg) for Plant A. The average removal efficiency of particulate was about 99.41% and the average removal efficiency of heavy metals could reach 94% or higher (except for Hg) for Plant B. The average removal efficiencies of Hg for Plant A and Plant B were 63.8% and 48.8%, respectively. The removal efficiencies of the existing air pollution control devices were close to that reported in the US EPA document (AP-42) for MSW combustors equipped with similar APCDs. Concentrations of heavy metals and particulate matter in gases can meet current emission standards in Taiwan for both plants, but particulate matter, Pb and Cd concentrations of Plant B are higher than the current emission regulations in Germany and Holland. As a result, more research is needed to investigate the way for further reduction of heavy metals and particulate matter emissions. In addition, the emission factors of heavy metals from MSW incinerators were established in this study as well.