Integrated Air and Water Phase Modelling of H2S Transport in Sewer Systems

Type of project

M.Sc.

Contact

Luis Roman (luro@dhigroup.com)

Topic

Hydrogen sulphide (H2S) is a major problem in many sewer networks where it can cause severe economic cost in maintaining the infrastructure due to corrosion, odor nuisances and dangerous working environment.

During the transport time to the wastewater treatment plant, the wastewater is transformed by ongoing biological processes. Aerobic heterotrophic activity leads to the growth of biomass, which attaches to the sewer pipe walls as biofilm and begins to corrode the dissolved oxygen in the wastewater. Anaerobic conditions can occur particularly in pressure mains, promoting the growth of bacteria that convert sulfate to sulfide. When sulfide is released as the gas H2S, it enters the sewer system atmosphere, causing odor and corrosion issues.

Many sewer systems are primarily designed to collect and transport sewage effectively but without consideration to prevent formation of H2S.

https://dhigroup.nos.co/images/681074021b47e10458c73814/Collection Systems.jpeg

Relevance to DHI

Today models applicable to use on large scale cities are limited (Qian et al., 2021). For modelling air flow in sewers several proposals and analyses are available (Edwini-Bonsu and Steffler, 2006, Wang et al., 2012, Lowe, 2017, Matos et al., 2021).

In order to address this problem, extending MIKE 1D (ref. MIKE 1D) with a prototype air flow module is key to designing effective odor and corrosion control strategies. This requires an integrated model of the liquid and air phases, including the formation of H2S.

What is the student's contribution

• Further implementation and development of the prototype air phase module in MIKE+
• Model configuration of novel odor control strategies in sewer systems