Development and testing of an indoor air scrubber for removing ammonia from air within poultry houses

Abstract

High levels of ammonia (NH₃) in poultry houses negatively affect bird BW, FCR, and disease resistance, and negatively affect the health of agricultural workers. The objectives of this research were to build and test the efficacy of a newly developed indoor air scrubber on reducing NH₃ concentrations. A full-scale prototype was constructed, and a series of experiments were conducted in a shop under various conditions using sulfuric acid for capturing NH₃. Dilute sulfuric acid (1%) was sprayed through 21 nozzles placed in six rows at multiple heights and orientations. Scrubbing efficiency was tested for two h at five NH₃ concentrations (10, 25, 50, 75 and 100 ppm) and two air flow rates (7,372 and 9,334 m³ h^-1) with three replications of each of the ten scenarios. The efficiency of the scrubber decreased with increases in air flow rate and NH₃ concentration. At the lower air flow rate the percent NH₃ reduction was 99, 98, 96, 94, and 93% when inflow concentrations were 10, 25, 50, 75, and 100 ppm NH₃, respectively, with corresponding outflow concentrations of 0.1, 0.7, 2.2, 4.2, and 7.3 ppm NH₃. At the higher flow rate, the percent reduction was 90, 91, 88, 87 and 87% at 10, 25, 50, 75 and 100 ppm NH₃, respectively, with corresponding outflow concentrations of 1.1, 2.4, 6.1, 9.9, and 13.1 ppm. When inflow NH₃ levels were relatively high (>50 ppm), the scrubber captured over 100 g N hr^-1. This technology would result in much lower NH₃ concentrations in poultry houses, which would improve poultry production and worker health, and capture valuable nitrogen fertilizer, while reducing air and water pollution