MSWI fly ash contains a much higher chloride content than MSWI bottom ash (Table 5 and 6, respectively). This may be due to the lime scrubber in the air pollution control system, which removes acidic gases such as HCl, thus resulting in a high amount of chloride content remaining in fly ash after the air pollution control system. The loss on ignition of ashes is around 4–13% for fly ash and 3–5% for bottom ash