Odor control

The absence of air and oxygen, known as anaerobic conditions, causes bacterial production of hydrogen sulfide H₂S, mercaptans, and other substances, all of which are toxic and foul-smelling gases. These unpleasant conditions spread and can be a source of complaints in a neighborhood because of their “rotten egg” or “rotten cabbage” smell.
 
Given its toxicity, H₂S causes eye, nose and throat irritation. It puts employees at serious risk in case of high-dose exposure in a confined space. Sludge may also contain pouches of concentrated H₂S that can be suddenly released by maintenance works. Several cases of death due to such H₂S exposure are reported every year.

H₂S can also be transformed into sulfuric acid, a cause of corrosion in the sewage network. This corrosion in turn threatens the lifespan of a sewage system’s infrastructure. 

Mercaptans are less poisonous than H₂S, but employees may develop headaches and become nauseous in case of prolonged exposure. At high concentration, workers may even have difficulty breathing.

To tackle these foul and toxic substances, Yara has developed Nutriox®, a comprehensive process that provides a healthy and safe environment for employees and prevents foul odors from spreading. Nutriox keeps H₂S from occurring, offering a long-term solution.

Nutriox comprises a special blend of environmentally friendly nitrates and of additional products blends, combined with an “intelligent” dosing and monitoring system to avoid over-dosing. This dosing system can be monitored online to attain an optimal solution. This offers preventive (NX product) and curative (Econox®) solutions.