Gaseous emissions (NH 3 ,N 2 O, CH 4 , CO 2 ) during pig slurry biological aerobic treatment and treatment by-product storages L. Loyon * , F. Guiziou, F. Be ´line, P. Peu Environmental Management and Biological Treatment of Wastes Research Unit, Cemagref, France Abstract. Field measurements of ammonia (NH 3 ), nitrous oxide (N 2 O), methane (CH 4 ) and carbon dioxide (CO 2 ) were made from raw pig slurry storage, from different biological aerobic treatments and from stores holding the treated products. Biological treatments consisted of intermittent aeration by (i) submerged ejector aerator, (ii) surface aerator and (iii) fine-bubble diffuser. Emissions were measured from the solid separated fraction of raw slurry and from whole-aerated slurry and from supernatant and sludge following sedimentation. Measurements of gaseous emissions were made under field conditions using the dynamic chamber technique for all liquids (raw slurry, reactors and treatment by-products) and by enclosing the heap of solid separated fraction in a large polytunnel with air drawn up by a fan. The results showed that the emissions of CH 4 , CO 2 and NH 3 were greater for the non-aerated effluents (raw slurry and separated solid fraction) which have a higher ammonium and organic matter level than for treatment by-products. N 2 O was only detected above the biological reactor and the concentration was low (b 1% of the total nitrogen entering the treatment plant). D 2006 Elsevier B.V. All rights reserved. Keywords: Ammonia; Methane; Nitrous oxide; Aerobic treatment; Pig slurry 1. Introduction In response to the EU Nitrate Directive some farms in Britanny (France) need to treat their pig slurry to comply to the land application level of 170kgN/ha and year. At present, 250–300 pig slurry treatment plants are in operation in the region. 80% of these plants employ biological treatments using intermittent aeration. Some biological treatment units are set up with physical separation devices (mainly decanter centrifuge and screw press) and 0531-5131/ D 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.ics.2006.02.017 * Corresponding author. E-mail address: laurence.loyon@cemagref.fr (L. Loyon). International Congress Series 1293 (2006) 299 – 302 www.ics-elsevier.com