UBC Tests

University of British Columbia tests Envron Ozone Odor Control System

UBC Testing (1980s)

The University of British Columbia and the British Columbia Ministry of Agriculture, tested the Envron odor control system for mushroom composting. A local mushroom composting facility was chosen as the test site. Ozone was  applied to the odorous gases using an Envron mixing system.

Odor panel tests are double-blind experiments in which people are given measured odorous gases or non-odorous gases to sniff through a machine that can accurately dilute samples. As the human nose is the ultimate arbiter for odors, this test indicates whether people would find the odors offensive or not.

Odor Panel Dilution Testing

UBC odor panel test results confirmed odor removal with the Ozone system. The untreated samples required dilution rates of between 1701-3043, which is typical of odorous substances. The Ozone treated samples were between 209-264, which is typical of non-odorous substances. As well, the treated samples had a faint Ozone smell, which is an almost antiseptic or sanitary smell.

These results are consistent with commercial uses for Ozone in other industries including sewage lift stations. Odors at lift stations result from anaerobic processes and Ozone kills these odors quite readily. From work in hog and poultry barns, Envron had already seen Ozone’s ability to quickly kill even very penetrating odors.

On-site testing of odor samples

One of the main principles in applying Ozone is to thoroughly mix the Ozone with the odorous gases. This can be accomplished in an open air facility through the use of a ventilation system that pushes Ozonated air across the tops of the compost. Or if the composting facility is enclosed, Ozone can be added to the ventilation system at the exhaust. A properly designed “destruct stack” is also used to ensure adequate mixing of the air and the ozone.

If the composting is done in an open-air facility, the Ozone Generators should be slightly oversized to compensate for a less efficient odor/Ozone mix. If the gases are exhausted through a ventilation system, then the generators can be downsized accordingly