title: Wind tunnel study of ammonia transfer from a manure pit fitted with a dairy cattle slatted floor.
abstract: In dairy cattle systems, most of the feces and urine go to the pit. At the manure pit level, mass transfer of NH3 ([Formula: see text]) has many factors, but practical difficulties hamper a controlled field evaluation. In this study, we propose a methodology for the determination of an alternative, more practical, pit transfer coefficient of NH3 (PTC), and compare it with [Formula: see text] determined from other scientific studies. The aims of this research study were: (1) to develop a wind tunnel set-up which mimics air flow patterns between the slats and above a clean section of a slatted floor section, featuring an aqueous NH3-emitting solution; and (2) to assess how air velocity, turbulence intensity, NH3 concentration ([NH3]) and PTC are influenced by inlet airflow ventilation rate (VR) forced deflection of the air above the slats into the manure pit through varying the deflection angle (DA) of a deflection panel and varying pit headspace height (HH). Main conclusions were: (1) the calculated PTC values presented a good fit to the power function of the air speed near the slats (u) (p < .001) while the average PTC (0.0039 m s(-1)) was comparable to [Formula: see text] values obtained from other studies, by remaining within the range of average values of 0.0015-0.0043 m s(-1); (2) VR and DA significantly impacted [NH3] profiles and PTC (p < .001) and (3) changing slurry pit from 0.10 to 0.90 m HH did not significantly impact [NH3] or PTC (p = .756 and p = .854, respectively).
authors.affiliation: a Technology and Food Science Unit (T&V) , Institute of Agricultural and Fisheries Research (ILVO) , Burg Van Gansberghelaan 115 Box 1, 9820 Merelbeke , Belgium.
authors.forename: Merlijn
authors.initials: M
authors.lastname: De Paepe
authors.affiliation: b Department of Biosystems Engineering , Ghent University , Coupure Links 653, B-9000 Ghent , Belgium.
authors.forename: Jan G
authors.initials: JG
authors.lastname: Pieters
authors.affiliation: a Technology and Food Science Unit (T&V) , Institute of Agricultural and Fisheries Research (ILVO) , Burg Van Gansberghelaan 115 Box 1, 9820 Merelbeke , Belgium.
authors.forename: Luciano B
authors.initials: LB
authors.lastname: Mendes
authors.affiliation: a Technology and Food Science Unit (T&V) , Institute of Agricultural and Fisheries Research (ILVO) , Burg Van Gansberghelaan 115 Box 1, 9820 Merelbeke , Belgium.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Van Weyenberg
authors.affiliation: c Deptartment of Flow, Heat and Combustion Mechanics , Ghent University , EA03 Sint-Pietersnieuwstraat 41, B-9000 Ghent , Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Merci
authors.affiliation: a Technology and Food Science Unit (T&V) , Institute of Agricultural and Fisheries Research (ILVO) , Burg Van Gansberghelaan 115 Box 1, 9820 Merelbeke , Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Demeyer
mesh_terms: D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000032:analysis*; D000818:Animals; D002417:Cattle; D003612:Dairying; D004784:Environmental Monitoring / Q000379:methods*; D005243:Feces; D008372:Manure / Q000032:analysis; D014865:Waste Disposal, Fluid
chemical_list: D000393:Air Pollutants; D008372:Manure; D000641:Ammonia
keywords: ammonia-emitting solution; automatic solution pH control; barn ventilation rate; flow patterns; pit headspace height