The formation of unpleasant odours in wastewater, sludge and sewage, due to anaerobic degradation in the absence of oxygen, can occur if water or sludge remains in certain areas of the plant for a period that allows the bacterial flora to consume all the dissolved oxygen (accumulation tanks, long transfer pipes, areas where sediment sludge is deposited). In these cases the water has negative values of redox potential showing that anaerobic conditions have been created, and these can lead to the formation of chemicals (for example H2S) that can have an unpleasant smell.
SOL has solved several cases of problems arising from these conditions by adding pure oxygen to the water and malodorous sewage beforehand, so as to avoid anaerobic conditions.
The ways of adding pure oxygen have been studied and proposed taking account of the specific needs of individual applications, where unpleasant odours may be given off from several different places. The use of this SOL technology makes it possible to limit the environmental impact of plant for handling and treating wastewater and sewage, with very little work required on the plant and very low running costs, especially compared with other solutions such as covering and isolating entire sections of the plant.