PROVISION OF SEWAGE AND SLUDGE TREATMENT FOR ATHENS

The existing WWTP, providing only preliminary and primary treatment for the 3.3 million inhabitants and the industries of the Athens greater area, requires upgrading to provide secondary treatment in accordance with the Urban Waste Water Directive. The activated sludge process was considered the most suitable to provide full treatment at the scale of operation required. The very limited land area necessitated the use of deep aeration tanks and rectangular, horizontal flow sedimentation tanks. Surplus activated sludge and primary sludge will be digested in an extended digestion plant. Dewatered sludge will be disposed to landfill. Alternative future sludge treatment and disposal options have been identified and quantified.