Estimation of emission factor for odorants released from swine excretion slurries

Abstract

In this study, the odorant emission rates from excretory wastes collected in sealed containers from a large swine facility were determined offsite in a laboratory using both raw slurry from ([1] windowless pigpen (WP) and [2] open pigpen (OP)) and treatedwaste samples ([3] composting facility (CF) and [4] slurry treatment facility (SF)). The emission rates of up to 41 volatile odorants were measured for 100 g waste samples (of all four types) in a 0.75 L impinger with an air change rate of 8 h(-1). The initial emission rates (mg kg(-1).h(-1)) for themost dominant species from each waste type can be summarized as: (1) WP: NH3 (16.3) and H2S (0.54); (2) OP: H2S (1.78), NH3 (1.69), and p-cresol (0.36); (3) CF: NH3 (7.04), CH3SH (0.30), and DMS (0.12); and (4) SF: NH3 (11.7), H2S (11.7), and p-cresol (0.25). Accordingly, the emission factors for the key odorant (m(E), kg.pig(-1))) for fattening pigs in the WP and OP facilities of S. Korea were extrapolated as 3.46 (NH3) and 0.38 (H2S), respectively. The emission factors were estimated assuming exponentially decaying emission rates and slurry production rates obtained from the literature.