Evaluation of a chemical scrubber for the removal of gaseous contaminants from recycled air.
A chemical scrubber was evaluated for its ability to remove two gases with differing water solubilities from recycled air. Operating parameters of the scrubber were also evaluated and included effect on air temperature and humidity. Ammonia, which has a high water solubility, was completely removed from the recycled air. Even when ammonia was continuously infused into the isolator at the rate of 1.0 liter/minute, the concentration in the recycled air never rose above 1 ppm despite concentrations of ammonia in the isolator of 4,000 ppm. Sulfur dioxide, which has a much lower water solubility, was not as rapidly removed. Continuous infusion of sulfur dioxide at the same flow rates used for ammonia resulted in increased gas pressure within the isolator. During operation of the scrubber, air temperature and humidity of recycled air rose significantly unless the water temperature to the unit was maintained at 15 degrees C. Overall, the chemical scrubber provided an effective adjunct to existing methods of purifying recycled air, but its application must be carefully selected in the laboratory animal facility.
D000336:Aerosols; D000388:Air / Q000032:analysis; D000393:Air Pollutants / Q000302:isolation & purification*; D000641:Ammonia / Q000032:analysis / Q000302:isolation & purification; D000818:Animals; D005374:Filtration / Q000295:instrumentation; D005740:Gases / Q000302:isolation & purification*; D006799:Housing, Animal; D006813:Humidity; D013458:Sulfur Dioxide / Q000032:analysis / Q000302:isolation & purification; D013696:Temperature; D014691:Ventilation
D000336:Aerosols; D000393:Air Pollutants; D005740:Gases; D013458:Sulfur Dioxide; D000641:Ammonia