BIOL241 Final: Unit 9
1 Apr 2016
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Document Summary
70% of earth"s surface is covered by water. ~70% of planet"s freshwater is locked away (glaciers, permanent snow, ground ice, permafrost) only 3% of that is freshwater no life without it accessible water is a precious resource. Purification of drinking water add anionic polymers, alum, disinfectant (e. g. , cl2, o3) goals: remove potentially pathogenic microorganisms decrease turbidity (amount of suspended particles) eliminate taste and odour reduce nuisance chemicals (e. g. , fe, mn) Severl m deep and goes through just by gravity. Reduction of typhoid fever (caused by salmonella typhi) in philadelphia following introduction of filtration & chlorination to treat drinking water. Similar reductions in other waterborne diseases were seen. Bacteroides (walkerton, ont outbreak in 2000) viruses: hepatitis viruses, rotaviruses, noroviruses (norwalk-like agents) protists (protozoa): giardia, cryptosporidium, entamoeba, balantidium, naegleria. H2o19 indicator organisms: coliforms: facultatively aerobic, gram negative, nonspore-forming, rod-shaped bacteria that ferment lactose with gas formation within 48 h at 36 c an operational definition rather than taxonomic.
