Intergrated approach for microbiological impact assessment of public wastewater treatment plants

Abstract

Wastewaters are a source of pathogenic micro-organisms in the environment. The microbial load and residues found in the final effluents of wastewater-treatment plants (WWTPs) depend on the WWTPs' abatement capacity and the final disinfection treatment systems applied to wastewaters before discharge into water. A historical database with data on surface and marine-coastal water quality and on the characterization of WWTP effluents was made using data from 1997 to 2004 to assess the microbiologic impact along the coast of the Venice province (Italy, northern Adriatic sea). The monitoring of river and sea discharges along the coast is integrated with the application of the Synthetic Pluriennal Faecalization Index (ISPF). The experimental study was conducted in the period from November 2002 to April 2004 by the Veneto Regional Environmental Prevention and Protection Agency. The results of this investigation on faecal contamination together with previous data are presented with a preliminary performance characterization of the WWTPs' disinfection technologies (sodium hypochlorite, peracetic acid, UV rays, and ozone).

Keywords:

• Total and faecal coliforms
• Faecal streptococci
• Escherichia coli
• Enterovirus
• Cytopathogenic virus
• Integrated analysis

Acknowledgements

The authors thank the two anonymous referees whose observations were particularly useful for significant modifications of the text and for the general structure of the paper, and the ARPAV Provincial Department of Venice, in particular the entire personnel of the Laboratory Service and the Territorial Service. Moreover, the authors thank Mr Lucio D'Alberto for the general review of the paper and the useful suggestions.