Reducing fatality risks from livestock manure storage facilities

摘要

The purposes of this study were to evaluate effects of environmental conditions and management factors on production of ammonia and hydrogen sulfide from commercial swine farm manure pits, and to examine reliability of typical commercial H_2S sensors for hog confinement buildings. Six swine farms with deep manure storage systems were studied. Parameters measured included air temperature, relative humidity, ammonia and hydrogen sulfide concentrations, and air velocity. Manure samples were collectedfrom each farm and analyzed for ammonium nitrogen, sulfides, total solids, and volatile solids. Concentration of hydrogen sulfide in the air is related to total volatile solids (TVS). Limiting total volatile solids can reduce hydrogen suifide and ammoniaconcentrations. Ventilation rates need to be increased during agitation. The time needed to be below the FEV (Fatal Exposure Value) and STEV (Short Term Exposure Value) for hydrogen sulfide can be forecasted for a given ventilation rate. Three hydrogensulfide sensors, one solid state and two electrochemical were evaluated. Evaluation included sensor accuracy, consistency, and durability. There is a lack of accurate and reliable hydrogen sulfide sensors for environments of swine buildings. Sensors costing 650 dollar only lasted approximately 6 months. Sensors ranging from 50 dollar to 400 dollar lasted only a few weeks to 2 months. Sensors must be protected from livestock facility environments to be effective and reliable.