Effect of operating conditions and input variations on the partitioning ofmetals in a municipal solid waste incinerator

The partitioning of copper, zinc, cadmium and lead between bottom ash and c ombustion flue gas was investigated in a municipal solid waste (MSW) incine rator. Material balances were established and transfer coefficients were de termined for seven 2-h periods. Statistical analysis of the data allowed as sessment of the uncertainty and investigation of the effect of waste input variations as well as process conditions. As a result, 6% of Cu, 54% of bot h Zn and Pb and 90% of Cd in the waste feed were transferred into the combu stion flue gas, the rest was found in the bottom ash. The uncertainty of th e partitioning in terms of relative width of 95% confidence intervals was e stimated as 33% for Cu, 7% for Zn, 7% for Cd and 21% for Pb. Multiple linea r regression indicates that, for the incinerator investigated, changes in c ombustion parameters have a negligible effect on the transfer coefficients of the selected metals; and the partitioning of Cd and Pb does not correlat e significantly with changes in the waste composition. A significant positi ve regression between the transfer of Cu and the chlorine content of the wa ste feed was observed. The results of this study are instrumental to determ ine the waste composition by analysing a single combustion product only.