책임운영기관 농촌진흥청 국립축산과학원 (로고)

This study evaluated the effectiveness of bio-curtains (hereafter referred to as curtains) installed in a pig facility from the perspective of ammonia emissions rather than ammonia concentration, as done in previous studies. The curtains were constructed by covering a rectangular frame with mesh, and they were installed outside the exhaust fans on the sidewalls of a pig facility where 48 finishing pigs (average weight 93 kg) were being raised. The experiment measured ammonia concentrations at the exhaust fan and the outer surface of the curtain under different spraying conditions (40 minutes and 70 minutes of spraying cycles) inside the curtain and exhaust fan operation rates (30%, 50%, 70%, and 100%).The ammonia emissions were calculated by multiplying the measured ammonia concentrations by the ventilation rates, and the reduction rates of ammonia emissions were then determined. The results showed that the ammonia emission reduction rates decreased step-wise with the increase in the exhaust fan operation rate under all spraying conditions. This trend was attributed to the decreased contact rate between the ammonia in the ventilated air and the spraying water inside the curtain due to increased ventilation rates and air exchange rates as the exhaust fan operation rate increased. Furthermore, when comparing the ammonia emission reduction rates between the spraying conditions, the reduction rate was approximately 3.90% higher under the spraying cycles of 40-minutes (23.66%) compared to the spraying cycles 70 minutes (19.76%). In conclusion, reduce the spraying cycle by 30 minutes (increasing the frequency of spraying by two-fold) enhanced the contact rate between ammonia and the spraying water, resulting in a 3.90% higher reduction in ammonia emissions.