Water and waste treatment Chapter 31, pp 785-800
A) water pollution = most problems when human feces enter the
water supply
1) microbial pollution - many diseases are transmitted by
“fecal-oral” route
(e.g. shigellosis, typhoid fever, cholera, hepatitis A, Giardia )
2) chemical pollution = toxins, carcinogens, metals, inorganic
ions such as
phosphates - leads to eutrophication which may cause algae blooms
resulting
in water pollution
3) coal mining - results in acid drainage from mines (like
sulfuric acid)
B) tests for water pollution
1) indicator organisms for microbial pollution
- should be present in human feces
- should survive in water as well as pathogens, but not normally
found in water
- should be easy to test for
- indicator organisms = coliforms
- coliforms = aerobic or facultatively anaerobic, gram -,
nonendospore forming
rods that ferment lactose producing gas within 48 hrs
- generally test for fecal coliforms = common inhabitants of
intestines such as
E. coli (MPN or membrane filtration Fig 31-7, p794)
C) Biological Oxygen Demand (BOD) = indicator of organic matter
in water
1) water samples are stored in airtight bottles 5 days in dark
2) after 5 days, dissolved oxygen is measured
3) more organic matter = lower dissolved oxygen (not good)
ecologically - more organic matter in water results in increased
BOD as microbes degrade the organic matter and consume oxygen in
the process = depletes oxygen levels in water resulting in death
of aquatic organisms
D) Waste water
1) waste water treatment - summarized Fig 31-1, p787
2) trickling filter Fig 31-2, p789
3) artificial wetlands Fig 31-3,
p 790
E) Solid waste
1) landfills
2) incineration
3) composting Fig 31-9, p796
F) Bioremediation
1) pollutants; biological magnification (Table 31-1, p797)
2) means of bioremediation = pp 797-798
Best Solutions:
REDUCE
REUSE
RECYCLE
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