Evaluating the Efficiency of Two Modules of Ammonia Capturing and Recovery Using Gas-Permeable Membranes in a Poultry House.

Ammonia volatilization from poultry manure is one of the major air quality and human health concerns associated with confined poultry production. High accumulation of ammonia may negatively affect the health of both workers and birds; therefore, this study was conducted to determine the efficiency of two ammonia capturing and recovery modules using gas-permeable membrane systems. The modules, flat and tubular membranes, were placed inside a 6.0 m X 6.0 m room in an UMES poultry house. The objectives of the study were to: 1) evaluate the performance of two gas-permeable membrane ammonia-capturing system models in capturing ammonia, and 2) assess ammonia emission rate between control and treatment rooms. In these systems, ammonia selectively passed through microporous, hydrophobic, gas-permeable membranes and was captured in a circulated acidic solution. Once ammonia gas passed through the membrane and was in contact with the acidic solution, ammonium (NH⁺₄) salt was formed, which was retained and concentrated in the acidic solution. The experiment consisted of three treatments: 1) control with no birds or membrane systems, 2) birds alone, and 3) birds with both membrane systems. Each room had 400 birds. The results of this study indicates that ammonia was successfully captured by both membrane modules reaching 57%ammonia recovery. Tubular membrane system was more efficient (78%) in capturing ammonia than flat membrane system. Moisture content (MC), Litter pH, and temperature significantly contributed to high ammonia emission in the poultry rooms. Average MC, pH and temperature were 23.6%, 7.3, and 72.7 for control rooms and 29.5% 7.4 and 74.3 for treatment rooms respectively. Chicken mortality rate was higher in the control room (6.5%) as compared to the room with the installed system (2.5%).The average feed conversion ratio (FCR) for broilers was lower in the experimental room (1.14) when compared to the control room (1.21).