Biocorrosion of Concrete Sewers in Greece: Current Practices and Challenges

• Main Authors: Georgios Fytianos, Vasilis Baltikas, Dimitrios Loukovitis, Dimitra Banti, Athanasios Sfikas, Efthimios Papastergiadis, Petros Samaras
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Sustainability
• Subjects: sewer corrosion; biocorrosion; concrete sewers
• Online Access: https://www.mdpi.com/2071-1050/12/7/2638

This paper is intended to review the current practices and challenges regarding the corrosion of the Greek sewer systems with an emphasis on biocorrosion and to provide recommendations to avoid it. The authors followed a holistic approach, which included survey data obtained by local authorities serving more than 50% of the total country&#8217;s population and validated the survey answers with field measurements and analyses. The exact nature and extent of concrete biocorrosion problems in Greece are presented for the first time. Moreover, the overall condition of the sewer network, the maintenance frequency, and the corrosion prevention techniques used in Greece are also presented. Results from field measurements showed the existence of H₂S in the gaseous phase (i.e., precursor of the H₂SO₄ formation in the sewer) and <i>acidithiobacillus</i> bacteria (i.e., biocorrosion causative agent) in the slime, which exists at the interlayer between the concrete wall and the sewage. Biocorrosion seems to mainly affect old concrete networks, and the replacement of the destroyed concrete pipes with new polyvinyl chloride (PVC) ones is currently common practice. However, in most cases, the replacement cost is high, and the authors provide some recommendations to increase the current service life of concrete pipes.