摘要：Mass balance of lead (Pb) in two municipal waste incinerators was investigated. Concentration of Pb in ash and wet scrubber effluent from the incinerators were determined, which gave an estimation of elemental balance based on a study about ash and wet scrubber effluent. Analytical variation of ash samples was as low as 3.1-4.9% (relative standard deviation, R. S. D.) for ash from electrostatic precipitator (EP), however, it increased to 7.1-31.4% for ash from bag filter, and 10.7-70.3% for bottom/mixed ash. Coagulating property of magnetic substance in bottom ash and lime powder used as bag filter injection were suspected as the cause of high variation. Content of Pb in municipal waste was 230.7-342.5g/tonne (metric ton). Assuming the Pb content in municipal waste to be 300g/tonne, Pb in municipal waste accounted ca. 20% of the usage of Pb-based chemicals in Japan. Distribution of Pb in feeded municipal waste to fly ash was 24.7-40.6%. Collection efficiencies of EP and bag filter calculated from wet scrubber capture were 98 and >99.99%, respectively.
