Odor Flux Measurements at a Facultative Swine Lagoon Stratified by Surface Aeration

Odorrelated complaints are a major concern of pork producers. Open manure storage and treatment facilitiessuch as uncovered anaerobic treatment lagoons are a major contributor to odor nuisance. Repeatable and valid fieldmeasurement techniques are needed for evaluating baseline odor emissions from existing livestock facilities and theeffectiveness of odor abatement technologies. A buoyant convective flux chamber (BCFC) for measuring odor flux from liquidsurfaces of dilute wastewaters was designed, constructed, and tested. Odor flux from a surfaceaerated stratified facultativelagoon at a 6000head swine finishing facility was measured with the BCFC. The swine buildings at this facility containedrecirculation flush pits initially charged with about 0.5m depth of effluent from the second cell of a twostage lagoon systemand discharged weekly to the first cell. The first cell was overloaded by 23% as an anaerobic lagoon with an estimated dailyloading rate of about 118 g of volatile solids per m3 of lagoon volume. To mitigate odor nuisance in the surroundingneighborhood, a statictube aeration system was installed in the first cell in an attempt to create an oxygenated surface layeron an otherwise anaerobic lagoon. Odor flux measurements with the new BCFC appeared to exhibit good repeatability basedon a limited number of tests. Odor flux of the stratified lagoon measured using a simulated wind speed of 1.1 m/s in the BCFCaveraged 1.72 odor units per s per m2 of lagoon surface area. The results are preliminary in terms of representing annual odoremission rates because odor flux is affected by wind and weather characteristics, results were based on only one constantwind speed that was simulated in the BCFC, and there were relatively few data points. The data was compared with odor fluxmeasured at two unaerated anaerobic lagoons.