Sludge management in highly urbanized areas

The management of sewage sludge is becoming of even greater concern since the generated volumes are increasing as a result of extended sewerage and advanced wastewater treatments. Agricultural use and landfilling face growing difficulties due to sludge increased contamination observed and stricter disposal criteria introduced, while incineration continues to be undesirable by the public, although technology is available today to meet extremely stringent air quality standards and guarantee a safe and convenient operation. Sludge management is particularly problematic in highly urbanized areas because of the large volumes in one location and the lack of suitable sites at convenient distance. In this paper, management options applicable to large urban centers are outlined and several case histories in Western and Eastern Europe, N. America and Asia described.