| Cooking meat is a source of outdoor atmospheric pollution as well as a source of indoor pollution (McDonald et al., 2003). Commercial kitchens produce emissions in solid, liquid, or gaseous phases that consist primarily of grease, proteins, particulate matter (PM), volatile organic compounds (VOCs), water, and combustion products from fuel and cooked food material. Particulate matter (PM) and grease can be in liquid or solid forms or a combination of both and may contain dissolved gases. Commercial-cooking activities have produced significant amounts of fine matter and hazardous air pollutants (HAPs) (Table 1.1) (Roe et al., 2004). Concerns about the emissions are firstly, the structural fires that occur while cooking due to the accumulation of grease particles in the exhaust ducts; secondly, atmospheric pollution; and thirdly, health issues. Carboxylic acids (i.e. octadecanoic acid and hexadecanoic acid), which are commonly found on the surface of the fast food exhaust ducts, when irradiated by UV light at 185 nm and 254 nm lost mass under controlled experimental conditions up to 36% (+/- 0.02 mug/cm2) after 8 hrs under low moisture (O2 at 5% RH). The carboxylic acid photolysis kinetic rate appeared to be a zero-order with a kinetic coefficient of 0.043 hr-1. Photocatalytic oxidation employing TiO2 and UV-C radiation at 185 nm and 254 nm reduced the mass of carboxylic acids (i.e. octadecanoic acid and hexadecanoic acid), which are commonly found on the surface of the fast food exhaust ducts up to 96% (+/- 0.02 mug/cm 2) after 8 hrs at 5% RH under N2 atmosphere. The carboxylic acid photocatalytic kinetic rate appeared to be a first-order with a kinetic coefficient of 0.347 hr-1. Factors that were tested were (i) temperature, (ii) ozone, (iii) relative humidity, and (iv) TiO2. |
