Modeling dust-borne odor dynamics in swine housing based on age and size distributions of airborne dust

In this paper, we derive a mathematical model characterizing the adsorption of odor on the surface of airborne dust in swine housing based on the concept of homogeneous surface diffusion of a complete mixing airflow system. The philosophy of the paper is to incorporate the age and size distributions of airborne dust into the diffusion model for evaluating the dust-borne odor dynamics in a ventilated airspace. A closed-form solution is presented here to allow a series of numerical experiments for investigating the effects of adsorption characteristics, the mean age of airborne dust, surface effective diffusivity, and dust particle size on the adsorption of odor to the existing aerosol. Results obtained show that the most favorable performance of a ventilation system in reducing odor concentrations is when the system model is operated under r(p) / √D(s)τ < 1, in which r(p) is the radius of an airborne dust, D(s) the effective diffusivity of bulk odor in air, and τ is the mean residence time of airborne dusts in ventilated airspace. The model enables engineers to evaluate the performance of the ventilation systems in reducing the odor emitted from stored manure in swine housing.