Odour formation is predominantly produced as a result of anaerobic activity and the subsequent degradation of organic matter. Reduced sulphur compounds form the majority of odourants associated with bad smells, such as hydrogen sulphide (H₂S). Sludge treatment and lagoons, for example, can produce malodours.

Odours can be addressed in either the liquid or gaseous phase. The former tackles the odourants before they have the chance to move to the gaseous phase and become a nuisance (preventative) and the latter removes the odourants once in the gaseous phase.

Biochemica has considerable experience in assessing and providing the Best Available Techniques (BAT) for odour control.