Portable bleach generators find use in locations far from water treatment facilities or where water treatment facilities are temporarily off-line. They are vital pieces of equipment in cases of humanitarian relief, during floods and other natural disasters.
These devices convert salt dissolved in water to chlorine bleach through an electrolytic process. Applied electrical current causes dissolved salt to convert into sodium hydroxide (NaOH), chlorine gas (Cl2) and hydrogen gas (H2). The generators then allow the combination of the sodium hydroxide and chlorine gas to form sodium hypochlorite, a type of bleach, which effectively disinfects drinking water.
The downside of this process is that the build-up of hydrogen gas byproducts within the generators reduces efficiency and creates a safety hazard. These portable bleach generators also require large amounts of electrical power, limiting their usefulness in the field. Furthermore, the processes used to generate bleach only produce low concentration bleach solutions, often less than two weight percent, which is insufficient for disinfecting drinking water.
A new bleach generator developed by the Army answers some of these deficiencies. It incorporates a housing containing brine, anionic, and cationic chambers. Electrodes in the anionic and cationic chambers separate salt from brine into hydrogen gas, chlorine gas, and an alkali and alkaline hydroxide mass. The hydrogen gas vents through a selective membrane and a pump conveys the chlorine gas to the cationic chamber, where it combines with the alkali and alkaline hydroxide mass to form a bleach solution. Under computer control, the user can select the desired bleach concentration for production. This portable solution may find application in disinfecting drinking water, purifying wastewater, and disinfecting surfaces and could be used in commercial, municipal or industrial bleach manufacturing.
This US application 20180065868 is related to US application 20180065085.
- Safely vents hydrogen gasses
- Increased electrical efficiency
- Generates higher concentrations of bleach than competing systems
- US application 20180065868 available for license
- Potential for collaboration with Army researchers