Assessment of leachability of harmful components from alternative fuels prepared with the use of sewage sludge / Ocena wymywalności szkodliwych składników z paliw alternatywnych wytworzonych z osadów ściekowych

Fuels, inclusive of those produced with the use of wastes, must usually be stored before their combustion or co-combustion in industrial processes. When stored outside, the fuels are exposed to adverse atmospheric impacts. The fuel quality may get worse then and fuel components which may be environmentally harmful may be leached out as well. The paper presents the assessment of potential environmental threads which result from the storage of fuels which have been produced with the use of municipal sewage sludge and other components, ie fuel made of the sewage sludge and coal slurry (PBS fuel), fuel made of the sewage sludge and meat-and-bone meal (PBM fuel), and that obtained with the use of the sewage sludge and sawdust (PBT fuel). Leachability of environmentally harmful components was studied, with special attention paid to heavy metals. Four methods were employed to evaluate the pollutant leachability levels; different environmental conditions were simulated in those methods. The studies and analyses demonstrated that the temporary surface dumping of PBS, PBM and PBT fuels was safe from the viewpoint of leaching of the harmful component to soil and/or water courses.