Proceedings

Treating wastewater of large cities constitutes a critical step in meeting the clean water demand worldwide. With the number of treatment plants (WWTP) steadily rising in many countries, safe, flexible and cost-efficient treatment technologies for the produced sludge are needed. First, the paper provides an overview of existing treatment routes, opportunities for reuse and current market trends in function of the sludge characteristics and other relevant parameters. Particularly the new trend for the use of sludge as renewable energy is discussed. Next, a series of proven industrial solutions is reviewed by means of case studies on projects in large urban centres such as Barcelona, Bruges, Antwerp, Baltimore, Chicago, and Copenhagen. Specific operating and safety features, the environmental impact of the facility and the public and governmental perception of the technology are highlighted. Finally, the advantages of an integrated water and sludge treatment approach is discussed.

KEY WORDS Biosolids, Compost, Dewatering, Dryer, Fertiliser, Incineration, Landfill, Pellet, Sludge, Wastewater