Determination of the patterns of hypochlorous acid release from foamed sodium hypochlorite solutions into the air in an evaporator of special design

The disinfection of air in premises, especially in the presence of people, is an important element of the system for the prevention of infectious diseases. A promising solution for this is to fill the premises with an antimicrobial chemical agent that would quickly neutralize pathogens directly at the moment they enter the air. It is advisable to use hypochlorous acid HOCl as such an agent. But traditional methods of administering HOCl into the air by aerosolizing its solutions may be accompanied by a number of risks that can be prevented by using gaseous HOCl. Therefore, it is relevant to develop evaporation devices that would take into account the specifics of chlorine-active compounds and determine the influence of various factors on the release of gaseous HOCl from them into the air being treated. During the study, a design of a device was developed in which the transfer of HOCl into the air is carried out by contact of the latter with a foamed working solution of sodium hypochlorite NaOCl. The HOCl concentration in the treated air mainly depends on its concentration in the working solution, which, in turn, is determined by the pH of the solution and the total content of free chlorine in it. Additionally, the influence of the air and working solution temperatures, the volume of the working solution, the power of air flows and other technological factors on the air HOCl concentration was studied. When using an electrochemically generated approx. 1000 mg/l NaOCl solution with pH 8.50–8.60 at 20 °C, it is possible to maintain the total chlorine concentration in the air flow with a capacity of 50 m3/h at a level of about 0.30 mg/m3 for a long time. Simple design, multifunctionality and the fundamental possibility of combining the processes of electrochemical synthesis of HOCl and its immediate administering into the air open up broad prospects for using the developed installations for continuous disinfection of premises