Abstract
Sewage sludge ashes from grate furnace and fluidized bed furnace were used in this research. This research was carried out to investigate the impact of combustion technology on sewage sludge speciation of heavy metals from sewage sludge ash. This was achieved by conducting a sequential chemical extraction procedure Community Bureau Reference (BCR). This study indicated that heavy metals in sewage sludge ash were dominant in immobile fractions. Moreover, it was stated that the combustion technology of sewage sludge did not have a significant influence on the mobility of heavy metals in ashes