5 Written questions
5 Matching questions
- acetic acid
- primary treatment
- activated sludge tank
- a physical separation. Some "biosolids" sink, some floats: grease, oil. Skimmed off. Reducing total amount of organics remaining in water. Little microbial activity involve
- b Range of radiation sensitivity: Lactobacillus
- c brief exposure to high temperature. Can't be too long or changes the quality of food. Used mostly in milk. Kills ALL pathogens, and reduce number of spoilage bacteria (extend shelf-life)
- d Organic acids. Vinegar. Often added to veggies, meats, mayo (pickles)
- e clarified water aerated by injection of air. A way to add oxygen so that aerobic microbes will use up oxygen.
5 Multiple choice questions
- (genus) bacteria associated with unpasteurized cheese and "pre-cooked meats"-hot dogs, deli meats
- (genus)-associated with poultry. Meant-contaminated during slaughtering and eggs that pass through cloaca.
- 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
- Organic acids. Added to juices, jams, tomatoes, soda (salt)
- Organic acids. Added to fruits, margarine, meat
5 True/False questions
stable sludge → End of water treatment process is left with __________. Very slow to decompose. Not likely to create big problems, can be buried in landfill. Could improve soils, but depend on what is in it.
Preservation → pathogens are trapped in floc. They get killed by _________: protozoans eat bacteria
antioxidants → 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.
UV light → inverted by N.Appert, big prize from napoleon. Heating of food in bottles and seal it. Main concern now is growth from any surviving bacterial spores.
competition → pathogens are trapped in floc. They get killed by _________: intestinal microbes are not well adapted to this environment. Lose out by ____ for nutrients to "good bugs'