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Fermentation Test (Phenol Red). John Snow’s Cholera Spot Map.

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Presentation on theme: "Fermentation Test (Phenol Red). John Snow’s Cholera Spot Map."— Presentation transcript:

1 Fermentation Test (Phenol Red)

2 John Snow’s Cholera Spot Map

3 Environmental Microbiology Environmental Microbiology: Treatment of Waste Water and Polluted Habitats 08/09/11

4 Waste Water & Sewage A little history Ancient Romans Modern sewage system London: pipes and high pressure water New York City: 20 years later http://www.kingcounty.gov/environment/wastewater/CSO/FAQ.aspx American waste amounts: (per person per day) 150 gal water 120 gallon of waste 5lbs trash

5 Sewage Treatment Purpose: –Eliminate potential pathogens and toxins –Decrease nutrient content (reduce microbial growth) –Reduce B.O.D. Biochemical oxygen demand (BOD): Amount of oxygen required for microbial decomposition of organic matter in sample 1.Determine O 2 levels 2.Incubation with microbes (5 days/20°C) 3.Determine O 2 levels 4.Calculate difference between 1 & 3  BOD  Organic Matter (waste)

6 B.O.D. Effects Raw sewage BOD: 300 to 400 mg/liter Natural water BOD: 5-10mg/L If you dump raw sewage into “receiving water”, the dissolved O 2 can be quickly depleted by microbes http://www.theepochtimes.com/news/4-5- 12/21351.html “200 million liters of sewage and industrial waste, much of it untreated, ooze into the Ganges from Varanasi” -Richard Stone, Science 2011

7 Multi-series process (US) 1° treatment 2° treatment (4 methods) Advanced Treatment Large Scale Wastewater Treatment Effluent (treated liquid) is discharged in body of water Sludge (solid) is further treated in anaerobic digester and disposed of

8 1° Treatment Filter & settle steps remove ~50% of solids & 25% of BOD

9 Anaerobic organisms act on solids (sludge) Various populations act sequentially Organic matter  organic acids, CO 2, H 2 Organic acids  acetate, CO 2, H 2 Acetate, CO 2, H 2  methane Remaining sludge dehydrated Disposal: incineration, landfill, fertilizer Anaerobic Sludge Digestion

10 2° Treatment Eliminates most of remaining BOD Microbial degradation of organic material 4 different options

11 Aerobic organisms degrade organic material to C0 2 and H 2 O

12 1.Activated sludge- commonly used Aerobic microbes (grown in flocs) Requires innoculation & aeration Resedimentation(save floc, treat sludge) 2. Trickling filter- smaller treatment plants Spray sewage over biofilm of aerobic microbes 2° Treatment Methods Bacteria Fungi Algae Protozoa Nematodes

13 2° Treatment Methods continued 3. Lagoons - shallow ponds where photosynthetic organisms create aerobic environment (treatment takes months) 4. Artificial wetlands Similar to lagoons Aerobic & anaerobic environments Involves bacteria, algae, plants, sedimentation Habitat generation

14 Advanced Treatment Physical, chemical or biological processes Increased expense over 1° and 2 ° treatment Removal of ammonia, nitrates and phosphates Ammonia stripping: Liberates gaseous ammonia from water Denitrification: use of bacteria (creation of N 2 gas) Chemical precipitation: phosphate removal

15 Performed before effluent is discharged Chlorine Ozone Ultraviolet light Disinfection Purpose: reduce numbers of microorganisms and viruses

16 Septic Tanks (Rural Areas) Collection in large tank –Settling of sludge –Anaerobic degradation Outlet to drainage field –Aerobic oxidization of organic material Potential Problems: Improper aerationImproper drainage Presence of pathogensToxic conditions

17 Water-borne disease Salmonella typhimurium Vibrio cholerae Leigeonella species Clostridium botulinum Escherichia coli Rotavirus Hepatitis A Polio virus Giardia lamblia Entomoeba histolytica Cryptosporidium parvum

18 Macha, Zambia Waste and Water in Underdeveloped countries Pit latrine verses Composting toilets

19 Ground Water: a clean source of drinking water?

20 1.Sedimentation 2.Flocculation of organic material 3.Filtration Removal of microorganisms Chemical absorption 4. Disinfection Drinking Water Treatment Process (US)

21 Test for indicator organisms: coliforms Drinking Water Testing (US) MPN Index: Maximum for drinking water: 0/1000ml (depends on collections per month) Example: If collect 40 samples: <5% can be positive If exceed positives/month must be reported

22 Activity Read through “Ailing Ganges” article and identify similarities and differences (3 total) between waste-water treatment in India and in the US.

23 The Golden Horn of Istanbul

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