5 Written questions
5 Matching questions
- stable sludge
- Staphylococcus aureus
- a in body, we convert nitrites and nitrates to ______ which is CARCINOGENIC.
- b 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.
- c 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
- d prevent, slow spoilage. Dilemma, need to inhibit or kill microbes but agents can't be too toxic.
- e (species) bacteria that grow in food, orginally from skin. Secrete toxin into food that induces vomiting and diarrhea. Self-limiting. Associated with SALTY foods.
5 Multiple choice questions
- canning temperature needed for high acid foods (pH<4.5). Kills all vegetative cells. If spores survive, can't germinate at low pH
- physical separation. Some "biosolids" sink, some floats: grease, oil. Skimmed off. Reducing total amount of organics remaining in water. Little microbial activity involve
- 0-4C. Slows metabolism and growth. Extend shelf life but not forever. Does create good conditions for psychrophiles. Ex) lactobacillus, listeria, pseudomonas
- (species) bacteria found in soil. Anaerobic in can food. Causes paralysis
- end product of anaerobic sludge digester. Organics will be fermented or organic acids + carbon dioxide. It is then converted to _________ by methanogens.
5 True/False questions
Pseudomonas → (Genus) spoil meat, secrete green fluorescent slime.
activated sludge tank → 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.
72C for 15 sec → ultra high temp. Usually sterilized milk, if sealed, don't need to refrigerate.
bacillus cereus → (species) bacteria that will grow in food. Secrete toxin. Causes vomiting, diarrhea. Source: soil bacteria in dust.
benzoic acid → Organic acids. Added to fruits, margarine, meat