Abstract: A combined instrument for the determination of the quantity of organic material present in a water sample is disclosed which features a first photosensor adapted to regulate the output of a source of ultraviolet regulation at a constant level and a second substantially identical photosensor positioned so as to view the same portion of the source of ultraviolet radiation as the first photosensor. The second photosensor produces a signal proportional to the transmittance of the ultraviolet radiation through the water sample and hence inversely proportional to the amount of organic material contained within the water. Such an instrument is also disclosed in combination with a water sterilizer in which the same source of ultraviolet radiation used as to monitor the amount of organic material present in the water is also arranged to provide ultraviolet radiation to the water or provide a bactericidal and sterilizing effect to the water.

Abstract: A closed water recycling system produces potable drinking water from total domestic waste-water, including household sewage. The system includes filtration and demineralization units. An electronic controller, which is preferably a microprocessor, monitors the operation of the system and automatically cleans the filter assembly, operates the demineralizer when the monitored variables indicate this is necessary, acts as a failsafe monitor to insure water quality, and shuts down the system in case of a malfunction. For example, the demineralizer may include acid and base regenerated resin beds in an ion-exchange system. When a monitor indicates that the beds require regeneration, acid and base regenerating solutions are supplied to the beds. The flow of regenerating solution and rinse is controlled by the electronics which sense conditions at the bed outlet.

Abstract: A closed water recycling system produces portable drinking water from total domestic waste-water, including household sewage. A microprocessor monitors the operation of the system and automatically back-flushes the ultra-filter assembly, regenerates the ion exchange bed when the monitored variables indicate this is necessary, and acts as a failsafe monitor to insure water quality by shutting down the system in case of a malfunction. For example, the bed includes acid and base regenerated resins having different specific gravities. When a monitor indicates that the bed requires regeneration, a water flush separates resins by specific gravity. Acid and bas regenerating solutions are supplied to opposite sides of the bed. The flow of regenerating solution is stopped when the salt band produced during regeneration approaches an outlet at the middle of the bed.