Real scale experience of innovative sewage sludge treatment in Italy: viability in transient economies

Sewage sludge management in Italy is in a transient phase. The old approach based on landfilling will be no longer adopted. The direct and indirect application on land is going to be subjected to more stringent regulations. Alternative solutions are necessary. To this concern, this paper analyses four Italian real scale case studies related to innovative solutions, based on prevention and thermal treatment: sewage sludge minimization through an integrated biological process, pyrolysis, gasification, wet oxidation. The four case-studies allow a comparison from the energy, environmental, economical point of view. The viability of these solutions in transient economies is analyzed too. Finally, the presence of mixed sludge and the effects of the different capacity of the plants are also discussed.