Degasification, odour control, evaporation

This chapter examines the gas-liquid exchanges that are applied in very different ways, depending on their purpose :

• eliminating a gas from water through stripping at normal temperature: CO₂ removal or gas adsorption in a "gas scrubber", especially applicable to the removal of odour-emitting gases (odour control);
• oxygen removed by vapor stripping in thermal degasifiers operating at temperatures close to boiling point;
• and, by extension to the latter, water evaporation, mainly seawater, for producing drinking or process water, or also for concentrating or even crystallising salts in effluents and, accordingly, avoiding discharge of any liquid into the environment, using evaporator-crystallisers.