The presentation deals with the treatment of sewage sludge, with a change of perspective towards a more sustainable and circular approach. The evolution of water treatment plants is illustrated, analysing the different types of sludge resulting from sewage processes, including biological, chemical and primary sludge.
Treatment and disposal technologies are explored, with a focus on stabilisation, dewatering and anaerobic digestion, aimed at reducing the volume of sludge and improving its quality. The paper also highlights the importance of minimising sludge production through innovative techniques such as cell lysis and the recovery of resources, including phosphorus, nitrogen and energy.
Sludge valorisation possibilities are also analysed, such as the production of bioplastics, use in agriculture and biogas generation through co-digestion. Finally, the future perspective of sludge management is presented, with the adoption of more efficient and environmentally friendly practices, in line with recent European directives, aiming at more sustainable treatment and greater recovery of materials and energy.
