The Aria™ odor control system is a true destruction process, based on the photocatalytic generation of reactive oxygen species and the subsequent large-scale decomposition of odor molecules and other potential contaminants. No other competitive system can make that claim. At its core, photocatalysis is characterized by the acceleration of the decomposition reaction of components in air in the presence of a catalyst, and depends on the ability of the catalyst to create electron–hole pairs, which generate radicals able to undergo secondary reactions. Among the critical success factors in the successful use of the Aria™ (patent pending) technology is the selection of the catalyst and other features to maximize the efficiency.

The earliest mention of photocatalysis dates to 1911, when Dr. Alexander Eibner integrated the concept in his research. This was followed by significant improvements in 1938, by Doodeve and Kitchener, with additional improvements in 1960 and 1970 by various researchers. Research and development in photocatalysis, especially in electrochemical photolysis continued, and in 2017 Chu et al. published a critical review.

Research carried out by American Air Scrubbers since the early 2000’s has resulted in the refinement of the catalyst systems, geometry, and photocatalytic effect to optimize the performance of the systems. The technology is well developed, based on sound scientific principles, and has been tested in several applications with each iteration generating a series of improvements which American Air Scrubbers has been able to consolidate in its patented technology. In the current embodiment, “odor molecules” are oxidized; not just adsorbed or masked or filtered. Cell walls, proteins, and related components are denatured/deactivated, essentially killing the microbes. Other researchers have confirmed these effects [1].

In other studies, reactive oxygen species (ROS) are emerging as important elements in the bacterial response to lethal stress. Three naturally occurring species, superoxide, hydrogen peroxide, and hydroxyl radical, are receiving the most attention [2,3]. Hydrogen peroxide, which can also be produced from superoxides, serves as a substrate for hydroxyl radical formation. This oxidative process can kill cells, since hydroxyl radical breaks nucleic acids, carbonylates proteins, and peroxidates lipids.

Bacteria contain protective proteins that can detoxify ROS (SodA, SodB, SodC, AhpCF, KatG, KatE) and counter damage (e.g., SoxRS, OxyRS, and SOS regulons). However, bacteria may also use ROS to self-destruct when stress is severe. Indeed, no protein-based mechanism has been identified that detoxifies hydroxyl radical. Association of ROS with the lethal action of multiple antibiotic classes has been taken as an example of stress-stimulated self-destruction, but complexities in the system have led to challenges. To clarify issues surrounding a debate that may have clinical importance, we review key aspects of the hypothesis that ROS contribute to antimicrobial lethality.

The optimal mode of operation of the Aria™ units in a recirculation mode. The required residence time in the system is short, and elimination of odor and microbial mater is controlled through the number of air changes in the space/volume.

1. Applications of Air Ionization for Control of VOCs and PMx Paper # 918 (Session AB-7a: Advances in, and Evaluation of, IAQ Control. Dr. Stacy L. Daniels Director of Research, Precision Air, a Division of Quality Air of Midland, Inc. 3600 Centennial Drive, Midland, MI 48642
2. Imlay JA. Pathways of oxidative damage. Annu Rev Microbiol. 2003;57:395–418.
3. Reactive oxygen species and the bacterial response to lethal stress Xilin Zhao and Karl Drlica.