5 Written questions
5 Matching questions
- Trickling filter
- secondary treatment
- Injection of ozone
- a peak efficiency of aerobic microbes in reducing organics. Secondary treatment.
- b Disinfection after secondary treatment depends on next use. Very reactive, very damaging to living thing
- c A way to add oxygen so that aerobic microbes will use up oxygen. Water sprayed from rotating booming water trickles through deep bed rocks. Pick up oxygen on rock-layers (biofilm) of decomposers. Remove organics as water passes
- d chemicals added primarily to stop chemical oxidation. Stop oxidation of fats that yields short chain fatty acids (odor, taste problems). May also have anti-microbial activity.
- e treating "clarified" water. COntains microbe, possible pathogens, dissolved organics, suspended organics.
5 Multiple choice questions
- pathogens are trapped in floc. They get killed by _________: protozoans eat bacteria
- Range of radiation sensitivity: Pseudomonas
- Organic acids. Produced by fermentation. Added to bread (Swiss cheese)
- part of secondary treatment in which microorganisms are used to reduce organics.
- Disinfection after secondary treatment depends on next use. Bleach, compressed gas. Very effective disinfectant that oxidizes everything such as proteins. Use at the end, inactivated by excess organics. Don't want to kill beneficial decomposers
5 True/False questions
Staphylococcus aureus → (species) bacteria that grow in food, orginally from skin. Secrete toxin into food that induces vomiting and diarrhea. Self-limiting. Associated with SALTY foods.
140C for 2 sec → high temp, short time (HTST)
benzoic acid → Organic acids-often naturally produced in fermented foods. Foods naturally preserved. (cheese)
sorbic acid → Organic acids. Added to fruits, margarine, meat
least sensitive → Range of radiation sensitivity: Pseudomonas