Effect of ozonation on particulate matter in broiler houses.

The effects of ozonation on particulate matter were studied on a commercial broiler farm. The farm consisted of 4 identical tunnel-ventilated houses (12.8×152.4 m): 2 houses were treated with O3 (maximum concentration 0.1 ppm) and the other 2 served as control units. The particle size distributions of total suspended particulate (TSP) samples from both control and treated houses were found to have very similar profiles with no statistical difference. The TSP concentrations were significantly higher in treated houses as compared with those in control houses, and the mean of the differences was 5.50 mg/m3. In both treated and control houses, there were substantial vertical TSP concentration gradients and the concentrations decreased with height. At broiler chicken height (0.28 m), TSP concentrations were 13±3 mg/m3 in control houses and 17±2 mg/m3 in treated houses. At human breathing height (1.55 m), TSP concentrations were 8±4 mg/m3 in control houses and 7±2 mg/m3 in treated houses. Particle phase NH4+ concentrations were higher in treated houses (ranging from 0.59 to 42.01 mg/m3 with mean=17.49 mg/m3) than in control houses (ranging from 0.34 to 13.55 mg/m3 with mean=4.42 mg/m3). The TSP samples from locations in the vicinity of the farm showed higher concentrations downwind than that upwind, but there were no significant differences observed among different ambient locations for TSP NH4+ concentrations. The results from this study did not show that direct application of ozonation technique has beneficial effects for particulate matter control in broiler houses.