At present, the water industry incurs significant costs in supplying and dosing chemicals into pumped main sewers to reduce septicity in the sewage and thereby reduce odours at the wastewater treatment works inlet.
Hydrogen sulphide is generated in the anaerobic conditions experienced in pumped sewers. Much of the sulphide is produced in a biofilm that forms on the pipe walls over a period of months. In situations where the biofilm is not allowed to build up, septicity (and therefore odour) is greatly reduced.
Four UK water utilities are working with WRc on this project to establish the effects on odour generation of removing and/or deactivating the biofilm on the walls of pumped mains. The expectation is that the removal of the biofilm will significantly reduce the need for dosing chemical and thereby reduce the high costs incurred.
This project aims to produce a robust, efficient and cheaper means of reducing odours in rising mains.