USES OF OXYGEN, OZONE AND CARBON DIOXIDE IN PURIFICATION PLANTS: because of the continuous evolution of human activities and of the gradual decrease in the values of polluting agents considered acceptable for re-introduction in the environment, the capacity of purifying plants needs to be updated continually or in any case it is necessary to find systems of giving greater flexibility to plants whose nature makes them very rigid. From this standpoint, the best way of improving purification plants based on active mud is to use pure oxygen to develop the plants. By using pure oxygen and ozone in this type of plant it is possible to solve numberless problems: from the formation of unpleasant smell both in the mud and in the catch basins of the purification plants to the digestion of excess mud, with the ensuing reduction in the quantity of material to be eliminated.

SOL has developed autonomously some original solutions for dissolving pure oxygen in water and can solve the problems that originate from continuous changes in the regulations, in the discharge systems, in the attitude of the general public towards the environment. The acid properties of carbon dioxide are exploited ever more frequently to neutralise alkaline discharge. By using carbon dioxide it is possible to:

• prevent ACIDIFICATION of the discharge, as it is a weak acid;
• prevent the discharge from exceeding the maximum limit allowed for controlled-level substances such as sulphates, which are usually produced by using sulphuric acid.

SOL has applied carbon dioxide on a large scale proposing original systems to users with problems in the treatment of alkaline discharge and now has importance references in all the industries potentially concerned.