Emissions of Odor, Ammonia, Hydrogen Sulfide, and Volatile Organic Compounds from Shallow-Pit Pig Nursery Rooms

Abstract

Purpose: The objective of this study was to measure emissions of gases (ammonia (<TEX>$NH_3$</TEX>), hydrogen sulfide (<TEX>$H_2S$</TEX>) and carbon dioxide (<TEX>$CO_2$</TEX>)), volatile organic compounds (VOC) and odor from two shallow pit pig nursery rooms. Gas and odor reduction practices for swine operations based on the literature were also discussed. Methods: This study was conducted for 60 days at a commercial swine nursery facility which consisted of four identical rooms with mechanical ventilations. Two rooms (room 1 (R1) and room 2 (R2)) with different pig numbers and ventilation rates were used in this study. The pig manure from both the R1 and R2 were characterized. Indoor/outdoor temperatures, ventilation rates/duration, <TEX>$NH_3$</TEX>, <TEX>$H_2S$</TEX>, <TEX>$CO_2$</TEX>, and VOC concentrations of the ventilation air were measured periodically (3-5 times/week). Odor concentrations of the ventilations were measured two times on two days. Three different types of gas and odor reduction practices (diet control, chemical method, and biological method) were discussed in this study. Results: The volatile solids to total solids ratio (VS/TS) and crude protein (CP) value of pig manure indicated the pig manure had high potential for gas and odor emissions. The <TEX>$NH_3$</TEX>, <TEX>$H_2S$</TEX>, <TEX>$CO_2$</TEX> and VOC concentrations were measured in the ranges of 1.0-13.3, 0.1-5.7, 1600-3000 and 0.0-1.83 ppm, respectively. The <TEX>$NH_3$</TEX> concentrations were found significantly higher than <TEX>$H_2S$</TEX> concentrations for both rooms. The odor concentrations were measured in the range of <TEX>$2853-4432OU_E/m^3$</TEX>. There was significant difference in odor concentrations between the two rooms which was due to difference in pig numbers and ventilation duration. The literature studies showed that simultaneous use of dietary control and biofiltration practices will be more effective and environmentally friendly for gas and odor reductions from pig barns. Conclusions: The gas and odor concentrations measured in the ventilation air from the pig rooms indicate an acute need for using gas and odor mitigation technologies. Adopting diet control and biofiltration practices simultaneously could be the best option for mitigating gas and odor emissions from pig barns.