Desalination 195 (2006) 109–118 0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved *Corresponding author. Wastewater reclamation by advanced treatment of secondary effluents M. Petala a , V. Tsiridis a , P. Samaras b *, A. Zouboulis c , G.P. Sakellaropoulos a a Chemical Process Engineering Laboratory, Department of Chemical Engineering, Aristotle University of Thessaloniki and Chemical Process Engineering Research Institute, 57001 Thermi-Thessaloniki, Greece b Department of Pollution Control Technologies, Technological Educational Institute of Western Macedonia, 50100 Kozani, Greece Tel. +30 (24610) 40161; Fax +30 (24610) 39682; email: psamaras@kozani.teikoz.gr c Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece Received 4 May 2005; accepted 17 October 2005 Abstract The objectives of this study were the investigation of the performance of an advanced treatment system, for the reclamation of secondary municipal effluents, and the study of the environmental quality of treated effluents. The secondary effluents from a conventional activated sludge process were fed to an advanced wastewater treatment system, consisting of a moving-bed sand filter, a granular activated carbon adsorption bed and ozone disinfection. The performance of this plant was evaluated by measuring the physicochemical, microbiological and ecotoxicological characteristics of reclaimed water. Sand filtration resulted in about 45% turbidity removal, while carbon adsorption enhanced mainly the removal of organic content, i.e. the total organic carbon removal exceeded 80%. The quality of treated effluents, obtained after ozonation by an ozone dosage of 26.7 mg/L, was found to comply with the respective US EPA proposed guidelines for urban reuse, food crop irrigation and recreational impoundments. However, a high ozone dose caused adverse effects on bacterium V. fischeri, possibly due to the formation of secondary oxidation byproducts. The annual cost of overall tertiary treatment process was evaluated to 0.24 €/m 3 , indicating the relatively high cost of these processes. Nevertheless, such processes are required in order to produce an effluent, with a high reuse potential. Keywords: Tertiary treatment; Reuse; Reclamation; Filtration; Ozonation; Ecotoxicity