Method and means for odor control in waste water lagoons

A method for controlling odor in a waste water lagoon comprises the steps of aerating a top horizontal layer of a lagoon adjacent its upper surface at a depth of approximately 12 to 24 inches by introducing air through a plurality of nozzles submerged in the layer to create a plurality of air bubbles in the layer. The nozzles are moved horizontally through the layer. A device for controlling the odor in waste water lagoons includes a support structure with an elongated boom operatively secured to the support structure and extending outwardly therefrom to operatively contact water in an adjacent lagoon. Compressed air is delivered through a plurality of downwardly extending nozzles on the boom into a layer of water on the top of the lagoon approximately 12 to 24 inches deep. Power elements are secured to the boom to cause the boom to move horizontally with respect to the lagoon while the compressed air is being delivered through the nozzles

Effects of Feeding Distillers Dried Grains with Solubles to Finishing Swine on Animal Performance, Manure Characteristics, and Odorous Emissions

Seventy-two finishing pigs were used to evaluate the effects of distillers dried grains with solubles (DDGS) on pig performance, manure characteristics, and odorous emissions. Three diets containing 0, 5, and 10% DDGS were fed during six 4-wk feeding periods. Week 1 served as a dietary adjustment period. Animals were housed in two feeding rooms (six pigs per room) with one treatment per room. A new group of animals (average initial Body Weight = 85.8 kg) was used for each feeding period. Diets were replicated four times. Rooms were equipped with individual shallow manure storage pits that were cleaned once weekly (day 7). On day 4 and 7 of each week manure pit samples and air samples in 10-liter Tedlar bags for olfactometry analysis were collected from each room. Dynamic dilution triangular forced-choice olfactometry was conducted using the Ac’scent International Olfactometer (St. Croix Sensory, Stillwater, MN) located in the Iowa State University Engineering Department of Agricultural and Biosystems. No differences in animal performance, as measured by average daily gain and feed efficiency, were observed (P \u3e .05). Greater feed disappearance (P \u3c .10) was observed from animals fed 10% DDGS. A nonsignificant trend of increasing odor, in terms of odor dilution threshold, was observed with increasing dietary concentration of DDGS (P = .16). A nonsignificant trend for increasing odor with increasing DDGS demonstrates the potential for diet formulation to improve odor. This increase in odor was likely due to the increased levels of dietary crude protein, amino acids, and elemental sulfur that were observed with increasing DDGS in the diets. Diet manipulation as a means to reduce odor needs to be investigated further

Comparison of Olfactometry, Gas Chromatography, and Electronic Nose Technology for Measurement of Indoor Air from Swine Facilities

Indoor air from swine finishing facilities was analyzed by olfactometry, gas chromatography (GC), and an electronic nose. Olfactometry used dynamic dilution triangular forced-choice. Air samples collected in Tedlar bags were analyzed using an AromaScan A32S electronic nose. Sixteen compounds, primarily nonsulfur protein metabolites were quantified by GC/mass spectrometry (MS) and an equation was generated to predict odor dilution threshold (R2 \u3c .3). Electronic nose evaluation of room air samples was not strongly correlated to olfactometry measures (r \u3c .2). However, the equation developed from the GC/MS analyses was capable of predicting the electronic nose response to air samples (R2 \u3e .8). The results suggest that human panelist responses may be based on detection of compounds that were not included in GC/MS quantification procedures and are not well detected by the electronic nose

Real-Time Ventilation Measurements from Mechanically Ventilated Livestock Buildings for Emission Rate Estimations

A six-state USDA-IFAFS funded research project (Aerial Pollutant Emissions from Confined Animal Buildings, APECAB) was conducted with the purpose of determining hydrogen sulfide, ammonia, PM10, and odor emission rates from selected swine and poultry housing systems. An important aspect of emission studies is to be able to measure the mass flow rate of air through the housing system. For this research project, the decision was made to study only fan ventilated buildings due to the difficulty in estimating mass flow rates through naturally ventilated buildings. This paper highlights the various techniques used throughout the study to determine mass flow rate through fan ventilated swine and poultry housing systems

Analysis of Lateral Design Pressures, Vertical Frictional Forces and Bending Stresses on Horizontally Corrugated Steel Silo Wall Panels

This study investigated the theoretical lateral design pressures, vertical frictional forces andbending stresses exerted by shelled corn on a wall configuration made of folded steel plates. Silo walls panelswith trapezoidal corrugations were considered. Lateral design pressures and vertical frictional forces werecalculated by using Janssen’s equations for pressures in deep bins and bending stresses exerted by ensiledcorn were calculated by using principle of engineering mechanics. Inclined sections of corrugations with 135ºfrom the horizontal plane had the highest lateral design pressures and vertical frictional forces. Corrugationswith tie bars had significantly lower bending stresses than the corrugations without tie bars. Using the resultsof this theoretical work, further studies can be performed for a complete silo model with a roof structure anda hopper bottom and wind forces and the shear stresses can be added to the model. This may give a betterinterpretation of the theoretical results on real models.</p

Real-Time Ventilation Measurements from Mechanically Ventilated Livestock Buildings for Emission Rate Estimations

A six-state USDA-IFAFS funded research project (Aerial Pollutant Emissions from Confined Animal Buildings, APECAB) was conducted with the purpose of determining hydrogen sulfide, ammonia, PM10, and odor emission rates from selected swine and poultry housing systems. An important aspect of emission studies is to be able to measure the mass flow rate of air through the housing system. For this research project, the decision was made to study only fan ventilated buildings due to the difficulty in estimating mass flow rates through naturally ventilated buildings. This paper highlights the various techniques used throughout the study to determine mass flow rate through fan ventilated swine and poultry housing systems.This is an ASABE Meeting Presentation, Paper No. 044178.</p