One of the important tasks of water treatment systems in the energy sector, pharmaceuticals, microelectronics, etc. industries is the removal of dissolved gases from water, primarily oxygen and carbon dioxide.

The main method for removing large concentrations of gases is physical desorption. In the case when it comes to low concentrations, chemical methods are used to bind the residual content of gases.

These methods require significant space for equipment placement, the use of reagents and often, due to contact with air, lead to secondary microbiological contamination.

A modern method for removing gases from water, which does not have the above disadvantages of classical methods, is membrane degassing. This method is based on the transfer of gases dissolved in water into a vacuum or a stream of inert gas (for example, nitrogen) through the pores of a membrane that is impermeable to water (hydrophobic). The use of such membranes makes it possible to achieve a large surface area, which accelerates the efficiency and speed of mass transfer, and also eliminates the contact of the treated water with air.

Membrane degassing plants are assembled from membrane contactors of various standard sizes, which makes it possible to apply the principle of modularity in the design of plants.

The process of membrane degassing, depending on the tasks, is usually carried out in one of three ways:

– removal of gases by means of vacuum;

– removal of gases with carrier gas;

– a combined method, the essence of which is the simultaneous supply of carrier gas and maintaining a vacuum. This method is the most efficient.

The residual concentration of dissolved gases in water can be controlled by changing the flow of water that passes through the modules, as well as the depth of vacuum or the rate of purge with an inert gas.

Disadvantages of membrane degassers:

– high capital costs in comparison with classical methods.

Advantages of membrane degassers:

– modular design;

– lack of phase contact;

– stable results;

– absence of chemical reagents;

– compactness;

– ease of installation and operation.