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Concentrated animal feeding operations (CAFOs) such as dairy farms are a source of odorous compound emissions. In this study, by identifying relevant odour sources within a 300-head dairy farm and quantifying their emissions, we determined the separation distances to avoid odour annoyance around the dairy farm with two empirical models (Austrian and German Verein Deutscher Ingenieure (VDI) model) and a dispersion model (AERMOD). Besides, this study ponders on the selection of an appropriate meteorological station that best represents the area surrounding the farm. Results show that the maximum separation distances of an exceedance probability of P = 15% determined by the two empirical and the dispersion models are 524 m, 440 m and 655 m, while the minimum values are 202 m, 135 m, and 149 m, respectively. The NE–SW stretching separation distances match well with the wind rose. The mean ratios of separation distances determined by the two empirical models to that of the dispersion model are 1.23 and 0.95. Moreover, statistics of the separation distances indicate good accordance between the empirical models and the dispersion model.

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To promote the photocatalytic oxidation (PCO) of hydrogen sulfide (H2S) in the gas phase, TiO2-coated glass fiber filters were packed in an annular photoreactor. Glass fibers coated with TiO2 thin films were characterized structurally and morphologically by field emission gun scanning electron microscopy (FEG-SEM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). Flow rate and H2S inlet concentration were evaluated to determine the performance of the reactor. Removal efficiencies up to 99% were achieved for flow rate of 25 L h(-1) (residence time of 121 s) and H2S inlet concentration from 12 to 14 ppmv. The long-term experiment presented H2S removal of 89% for 16 h. After 28 h of continuous use, H2S degradation was observed at 64%, which suggests that the photocatalyst was losing activity due to deactivation. Moreover, the kinetics of the PCO of H2S according to the Langmuir-Hinshelwood (L-H) approach along with the mass balance of a plug-flow reactor was modeled. The reaction constant (k) was calculated at approximately 10.5 μmol m(-3) s(-1) and the adsorption constant (K) of approximately 5263 m(-3) mol with linearity (R2) of 0.98.