Leaching of pahs from fly ash - sludge blends

This work presents results of the release of polycyclic aromatic hydrocarbons (PAH) from granules composed of fly ashes, which are the product of hard and coal combustion and sewage sludge. 3 types of granulates by a weight ratio of ash to sludge 3:7 and 1:1 were used. The research of PAH leaching was conducted within a simulated period of 24 months, with the examination of PAH washing out every three months. The highest amounts of PAH (297 - 330 ng/kg dw.) were obtainedjrom granulates containing 7 parts by weights of sewage sludge (3 times higher in comparison with the granulate containing ash and sludge in ratio of 1:1). The maximum PAH release from all the examined granulates took place in the 9 month of the research. Benzo(k)fluoranthene revealed the highest fraction (67.4-76.0%) of all examined compounds.