The Forecasting of Hydrogen Sulphide Gas Build-Up in Sewerage Collection Systems

Abstract

The presence of hydrogen sulphide gas in sewerage collection systems is a common source of odour nuisance, corrosion of sewers and toxic atmospheres. The hydrogen sulphide build-up in the sewer air may be related to sulphide concentrations in the flowing sewage and with other factors, such as turbulence, aerodynamic conditions of the ventilating air now and roughness of the unsubmerged surfaces. In the present work, a mathematical model is presented for forecasting hydrogen sulphide gas build-up along gravity sewers, which is based on the analysis of a differential mass balance equation applied to a sewer reach. Good correlation was obtained, comparing the results of the model with experimental information collected in the Funchal main trunk sewer. Funchal city is the capital of Madeira, a Portuguese island in the middle of the Atlantic Ocean, and its main trunk sewer was put into operation at the beginning of 1980.

Modeling Hydrogen Sulfide Emission Rates in Gravity Sewage Collection Systems

“…Of these five processes, the rate of H 2 S emission into the sewer environment has been only scantily addressed scientifically. Other processes, such as the factors governing formation of sulfides in sewer systems and the biological oxidation of sulfides (either in the aqueous or in the gas phase) have been studied intensively and equations for their predictions have been proposed both for gravity sewers and for pressure mains (Davy 1950;Pomeroy and Parkhurst 1977;ACPA 1981;Nielsen and Hvitved-Jacobsen 1988;Matos and Sousa 1992;Matos and Aires 1995;Elmaleh et al 1998).…”

“…The most recent approach is to combine a number of smaller models, each one addressing a different process, into a comprehensive model for sulfide generation, emission, and possible corrosion rate (Matos and Sousa 1992). However, it would appear that the weakest link in most of these models is related to H 2 S emission as a function of the hydraulic conditions.…”

Hydrogen sulphide removal in waste water treatment plant by compact oxidative scrubbing in Aquilair Plus™ process

“…Waste water treatment plants (WWTPs), among other facilities, can cause odour emissions likely to generate significant annoyance in the neighbourhood (Frechen, 2004). Hydrogen sulphide is the predominant odorous molecule associated with sewage (Gostelow et al, 2001) and its formation in sewers has been extensively studied (Matos and de Sousa, 1992;Nielsen et al, 1998). In order to treat these odorous atmospheres, some classical processes are implemented: biofilters can be an alternative but the most common used are packed towers, in which pollutants are removed by chemical scrubbing (Bonnin, 1991;Chen et al, 2001).…”

New compact scrubber for odour removal in wastewater treatment plants

“…Typically, the species identified as responsible for odours in WWTPs are reduced to sulphur, nitrogen, fatty organic acids, aldehydes or ketone compounds. H 2 S is the predominant odorous molecule associated with sewage (Bonnin, 1991;Gostelow et al, 2001) and its formation in sewers has been extensively studied (Matos and Sousa, 1992;Halkjaer-Nielsen et al, 1998). Odour control at WWTPs is most of the time realised by chemical scrubbing (Bonnin, 1991;Chen et al, 2001).…”