Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 12/12/2006
Publication Date: 9/17/2007
Citation: Loughrin, J.H., Lovanh, N.C., Mahmood, R. 2007. In Situ Measurements of Malodors in a Swine Waste Lagoon. ASABE Annual International Meeting.
Technical Abstract: Obtaining data on the concentrations of malodorous compounds contained in waste lagoons is essential if the factors affecting their emission are to be described. We monitored selected compounds in a 0.4 ha lagoon that received waste from approximately 2000 sows. Phenol, p-cresol, m-cresol, p-ethylphenol, indole, and skatole were measured by the use of equilibrium samplers consisting of submersible stir plates and stir bar sorbtive sampling using polydimethylsiloxane-coated magnetic stir bars. The samplers were deployed at depths ranging from 10 to 170 cm at two locations within the lagoon, and the concentrations of the compounds tracked during the late summer to early fall of 2006. After the lagoon was partially drained for crop application, all samples were taken at 10 cm. At the same time, compounds were monitored 40 cm above the surface of lagoon by passing air at 100 ml min-1 through thermal desorption tubes containing 7-cm long beds of Tenax GR or Tenax TA adsorbents. Submersed samplers and air collection platforms were deployed for three hours during which time data on environmental factors such as air and water temperature, humidity, and solar radiation were collected. Levels of malodorous compounds were higher in the top layer of the lagoon than at the middle or bottom of the lagoon. Skatole concentration, for instance, averaged 54, 24, and 38 ng mL-1 in the top, middle, and lower depths, respectively. During a span of intermittent lagoon drainage, concentrations of malodorous compounds fluctuated widely and after the drainage period averaged 16-fold higher than prior to drainage probably due to a relatively high contribution from fresh waste. Tenax TA proved superior to Tenax GR for sampling polar malodorous compounds above the lagoon surface.