Application of ion-exchange-based additive to control ammonia emissions in fattening pig barns with slatted floors

The intense productivity related to the livestock sector has led to the development and application of different technologies and procedures to mitigate, mainly, NH3 emissions. The addition of ion-exchange-based additives, such as Active NS, is one of the practices that may help reducing nitrogen emissions. In this study, the use of Active NS to mitigate NH3 emissions in pig barns with slatted floor has been assessed during three pig fattening cycles. Two naturally ventilated identical barns were used to carry out the experiments at full-scale. Active NS was only applied in one of the barns while the other one was used as a reference to compare ammonia emissions between both barns during a 1-year monitoring campaign. The concentration of ammonia in the air at different points of each barn besides the ammonia emission rate generated directly from the slurry were measured monthly. The maximum reduction of ammonia emission (ranging from 17.6% to 38.3%) was systematically obtained at mid fattening cycle, where the concentration of Active NS in the slurry was between 40 and 45 g m(-3). The retention of ammonium into Active NS structure caused an increase of total nitrogen in the slurry of 19.6% compared to the control barn. This result indicated that the application of Active NS promoted better nitrogen retention in the slurry, thus avoiding its loss by volatilization during the storage of slurry. Lab-scale experiments were additionally performed in order to validate the results observed at full-scale under controlled conditions resulting in similar findings and confirming the adequacy of Active NS optimal dosage. (C) 2021 Elsevier B.V. All rights reserved.