Studies regarding obtaining unconventional fuels from sludges coming from tertiary treatment of some wastewaters

Sludge obtained in the tertiary stage of wastewater treatment can become a source of potential fuels. Up to now, the methods applied for making the best use of such sources have aimed at obtaining energy through indirect processes and using sludge for agricultural land improvement. However, most conversion methods applied on a national scale have major technical and economic disadvantages, as well as a negative impact on the environment. The present paper summarizes the research work performed by the authors for the direct use of sludge under the form of solid fuel, as well as the optimisation of the disposal of sludge resulted from biological wastewater treatment.