Why Aren't H<SUB>2</SUB>S Concentrations Logical? (What We Are Missing In Daily H<SUB>2</SUB>S Patterns)

Abstract

Hydrogen sulfide (H 2 S) is a major issue in sewer collection systems. H 2 S affects the public's quality of life through odor issues and is a safety concern for sewer workers. Economic impacts result from H 2 S caused corrosion as well as safety concerns and the migration of odor. H 2 S concentrations in the sewer headspace demonstrate a diurnal pattern that is not explained by current models. Odor complaints are primarily a result of the peak concentration levels and may be more accurately predicted with a better understanding of the diurnal H 2 S concentration patterns. A simple model is proposed that addresses a stationary sewer atmosphere segment. The relationship between the factors is extremely complex. Utilizing field tests, a strong case can be made that the normally submerged slime layer, when exposed, will emit directly to the sewer atmosphere. To the author's knowledge, direct emission has not been previously proposed or documented. Corrosion patterns documented in previous studies match the expectation of high exposed slime layer emissions in combination with diffusion of the H 2 S.