Biological deodorisation

Because of the absence of air and more particularly of oxygen, wastewater when it is collected becomes septic and can be extremely malodorous, sometimes directly at the network level and usually on arrival in the wastewater treatment plant. 

At the treatment plant level, the storage and treatment of the sub-products resulting from the treatment of wastewater (sludge, scum, etc) can also release strong smells.

In the wastewater treatment plant, the nuisances are mainly related to the presence of sulphur compounds already partially formed in the network and, at a lower degree, to the presence of nitrogenous compounds.

The sulphuric compounds that form the majority of the concentrations in the foul air from the pre-treatment, and the thickening and dewatering of the sludge offer the highest olfactive thresholds. The nitrogenous compounds (ammonia, amines) are mainly present in the sludge treatment rooms.

To prevent the propagation to the surroundings of the odours produced in the treatment works, and to provide a healthy and safe environment to the operation personnel, all risks of releasing malodorous gas are minimized by using a biological odour removal system, called Alizair™.