Investigations of Chemical Deterioration Factors Affecting Concrete Structure and the Degradation of Protective Linings in Sewerage Facilities
By T. Miyamoto, A. Kuba and C. Abe
Concrete Journal, Vol.64, No.11, Nov. 2026
- Synopsis
- Concrete is widely used in wastewater treatment plants (WWTPs), where chemical deterioration, typically caused by sulfuric acid, occurs. This paper presents, as examples, the results of investigations of hydrogen sulfide concentrations in manholes, sewage treatment systems at WWTPs, and the deterioration of protective linings at WWTPs. Environmental conditions in sewerage facilities are not uniform, and the concentrations of deterioration factors varied between sewer pipelines and WWTPs and, even within the same WWTP, depending on the treatment process. Hydrogen sulfide concentrations in manholes were high not only immediately downstream of force-main outlets but also downstream of locations with standing water, averaging approximately 10 ppm. In the sewage treatment facilities at WWTPs, the findings indicated that deterioration may be caused not only by sulfuric acid but also by free carbon dioxide. Deterioration of protective linings was reported at half of the WWTPs that had been in service for more than 20 years.
- Keywords:
- Sewerage, Manhole, Wastewater treatment plant, Protective lining, Hydrogen sulfide, Aggressive carbon dioxide
