Hydrogen sulphide, or H₂S, is a toxic gas that is often found in sewerage systems, sewage treatment works and industrial wastewater treatment facilities. It develops in sewers because of biological activity in the wastewater.
There are many systems to combat odour pollution linked to hydrogen sulphide. Some only mask the problem; others, such as YaraNutriox are preventive. YaraNutriox is a natural process developed by Yara since the late 1980s. It is used by municipals at hundreds of locations with hydrogen sulphide problems.
YaraNutriox is a system for preventing hydrogen sulphide and the odours it produces. YaraNutriox acts at the source of the problem and automatically injects precise amounts of specific nutrients, where and when needed, into sewerage systems or sewage treatment works. Using complex modeling and dosing equipment it ensures the optimum injection rate to eliminate odour complaints from the community, and also prevent the risk of employee or public exposure to this highly toxic gas.
Since 2010, H₂S has been considered a toxic gas by the European Union. The gas is deadly if concentrations become too large (> 1000 ppm) and its presence is usually detected by its characteristic “rotten eggs” smell. However, above a certain concentration, hydrogen sulphide anaesthetises the olfactory nerve, so that the smell cannot be detected. Hence the importance of preventive measures, such as YaraNutriox sold by Yara.