Evaluating sulfuric acid production models for predicting microbially induced concrete corrosion in sewer systems

Abstract

Microbially induced concrete corrosion (MICC) is a degradation process in wastewater systems that significantly reduces service life of cement‐bound sewer pipes. Several models are described in literature that correlate acid production rate with the main influencing parameters: H2S concentration in the sewer atmosphere, pH value at the concrete surface, temperature and relative humidity. This study selects three such models and applies them to a long‐term field trial conducted over five years across different wastewater shafts in Berlin. Based on the time‐dependent influencing factors, constant equivalent values are derived that result in a comparable level of mortar degradation. Using these equivalent concentrations, the theoretical acid production is calculated for the different models. Finally, a suitable approach is identified for future use as input data in a simulation software, which aims to fully represent the corrosion process, enabling reliable predictions of the long‐term durability of cement‐bound sewer pipes.