Sewer Reticulation Analysis

Filth flowing out from sewage pipe angle shot

Sewer Reticulation Analysis

Bioremedy has the ability to model and report a clients’ susceptibility to sulphide production within their sewer reticulation. We supply OdaLog Hydrogen Sulphide monitoring equipment.

Background in Biological Breakdown of Sewage Waste and H2S Generation

The majority of wastewater discharged to a sewerage system is aerobic as it contains dissolved oxygen.  Aerobic and facultative bacteria initially use dissolved oxygen in the sewage to breakdown organic matter in the sewage as follows –

Organics + oxygen   →   CO2 + H2O + energy

Typically, after approximately one to four hours the dissolved oxygen is consumed in a rising main or wet well and the sewage turns septic.  The rate at which the sewage turns septic is dependent on factors such as temperature, availability of nutrients and pH.  In particular, built up fat, oil and grease (FOG) on a pump station wall and in a rising main can turn sewage septic prematurely as the FOG has an extremely high biological oxygen demand.

Once the sewage turns septic, anaerobic and facultative bacteria begin to break down waste as follows –

Organics + NO3  →  CO2 + N2 + energy

Organics + SO4  →  CO2 + H2S + energy

Organics  →  organic acids + CO2 + H2O + energy

↳ CH4 + CO2 + energy

As H2S gas is released in a pump station wet well, discharge manhole  a common sulphur bacterium performs the following reaction to form sulphuric acid (H2SO4) –

H2S + oxygen  →  H2SO4  +  energy