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<OL> <LI> Determine the efficacy of ozone to reduce biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) in food processing plant wastewater that has high concentrations of fat, protein, starch or locust bean gum. These chemical moieties represent different nutritional or additive families commonly used in the food industry. <LI> Determine the efficacy of ozone to reduce bacterial populations of Escherichia coli ATCC 4350, Staphylococcus aurus ATCC 27661 and Bacillus stearothermophilus ATCC 10149 thermospores in the presence of high concentrations of fat, protein,starch or locust bean gum.
Objective 1: One percent mixtures/solutions of heavy whipping cream (45% fat), sodium caseinate, starch and locust bean gum will be prepared in deionized water. Sterile deionized water will be used as a control. Using a Longmark PurePower O3 ozonator, solutions will be ozonated in an aerator chamber (Ace Glass Incorporated, Vineland, NJ) for 0, 2 and 10 minutes at 0.4 to 0.5 ppm ozone as measured by the DPD method. This procedure will be replicated in triplicate. Solutions will be treated at room temperature. The pH of each solution will be measured before and after each ozonation treatment. The Biochemical Oxygen Demand (BOD5) will be measured on all samples as described in Standard Methods for the Examination of Water and Wastewater (1992). The Chemical Oxygen Demand (COD) will be measured on all samples using the closed reflux, colorimetric method (COD Digestion Reagent Vials - High Range, Hach Company,Loveland, CO). <P> Objective #2: One percent mixtures/solutions of heavy whipping cream (45% fat), sodium caseinate, starch and locust bean gum will be prepared in deionized water. Class O buffer (Standard Methods of the Examination of Dairy Products, 1992) will be used as a control.Three bacterial strains will be used in this experiment: (1) Bacillus stearothermophilus ATCC 10149 thermospore suspension (Difco, Detroit, MI), (2) Esherichia coli ATCC 4350, and (3) Staphylococcus aureus ATCC 27661. The thermospore solution will be stored under refrigeration until immediately before use to prevent spore germination. The suspension will be diluted at the rate of 1 ml per 9 ml sterile Class O buffer. The E.coli culture will be grown in nutrient broth supplemented with 0.2% yeast extract (NB-YE) and the S. aureus culture will be grown in brain heart infusion broth supplemented with 0.2% yeast extract (BHI-YE) . Cultures will be grown for 18 hours at 32C on a rotary shaker (100 RPM agitation). A 1 ml sample of each culture will be diluted into 99 ml Class O buffer.One ml each of diluted thermospore suspension and diluted E. coli and S. aureus cultures will be added individually to 14 ml solutions of whipping cream, sodium caseinate, starch, locust bean gum and buffer for use in the ozonation trials. Solutions will be ozonated in an impinger (Wheaton #753332, Wheaton Scientific, Millville, NJ) for 0, 2 and 10 minutes at 0.4 to 0.5 ppm ozone. This procedure will be replicated 5 times. Statistical Analysis: Experimental results will be analyzed using ANOVA in a completely randomized block design.