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Microbiology of Water & sewage I. Why is it important to know? 1. Disease prevention A. - Vibro cholerae Severe diarrhea (white rice) Loss of 20 L/day Vomiting, muscle cramps 5 pandemic since the early 1800's 1832-1836 200,000 Americans dies 1961 - Indonesia 1989 - Africa 1991 – Peru B. - Salmonella typhi Salmonella infections Enteric fever Headache Intestine rupture Bleeding C. - inflammation of the brain or meninges D. - intestinal inflammation Waterborne Disease E. - skin inflammation 1. 1993 - 94 30 outbreaks in 17 states (22 from microorganisms, 8 chemical - lead, copper, floride). a. Drinking water, pools, rivers, ponds, lakes 2. 403, 000 crytosporidisses - Milwuawkee ( 5 outbreaks) a. Mostly Gastroenteritis & Dermatitis 3. 100 chemical contamination a. Lead, copper 4. Remainder from known organisms. ( 33% parasites. 23% bacteria, 26% chemicals, 16% unknown) 2. Prevent pollution - drinking water, pools, whirlpools, hot tubs, ponds, lakes, rivers . Why ? Water is needed for everyday living. II. Sewer Systems A. Since roman times. B. 1840 - Chadwick - sewer system & use sludge for fertilizer. 1. to increase water pressure. 2. Did not accomplish Sludge C. 1848 - England , because of the threat of chorea. D. 1866 - NY city, because of the threat of chorea. E. By 19th century, most of the major cities have some type of sewer system. Review What disease is the main reason for the sewage system? III. Water testing & treatment A. Why? Detecting & removing contamination (pathogenic microorganisms). Avg. American 150 gal of water/day 4 lbs of food 19 lbs of fossil fuels Per Day 120 gal of sewage 5 lbs of trash 2 lbs of pollutants B. Three types of water 1. City with 1 million people 120 million gal of raw sewage - fit for drinking. 2. - Poisonous chemicals or pathogenic organisms (clear & sparkling). 3. - may or may not be contaminated but has an undesirable appearance or taste. B. Typical treatment 1. Water stands to let solid mater . 2. Water is removed & mixed with flocculent to bind with bacteria & viruses ( - Chemical) - clumping. 3. Clumping settles out. 4. Filter through gravel or earth. 5. Disinfect with . , C. Types of Treatment Organic to inorganic Mineralization or Stabilization 1. - removal of large objects ( Screening & Sedimentation). 2. - chemical is added to convert remaining material in sewage into an odorless inorganic substance. 3. - Removal of phosphates & nitrogen - may cause eutrophication. D. Microorganisms Degrade the components of Sewage to inorganic Compounds. 1. - microbial oxidation = Carbon Dioxide & inorganic nitrogen containing nutrients for plants. 2. - Carbon dioxide & methane E. (BOD) - Oxygen consuming property is equal to the proportional to the amount of degradable organic material. 1. Incubate a sample for 5 days @ 20C. 2. Measure oxygen consumed growing in the sample (eat organic matter). 3. Aerobic microorganisms- CO2, Anaerobic microorganisms. 4. High = High = High IV. Role of bacteria in Purification of stream & rivers Beginning Dump wastes in river & there was no harm to the ecosystem. - microorganism (aerobes (more efficient)& anaerobes(less efficient)) were able to break down the organic wastes to inorganic to be recycled back into the system. Now - Overload. consume oxygen (air) quickly for the river. in micro floral and not all aerobic bacteria get oxygen, therefore they die. Anaerobic bacteria can not keep up with the break down of wastes. Large organisms (plant & animals) start to die off & add to the waste build up. V. Methods for Wastes treatment A. Primary Treatment 1. Remove material that will settle out (sticks, rags, & trash). 2. Removed by a series of screens then stand for 90 minutes to 2 hours. 3. Sometime flooculate is added alum to settle out quicker. 4. Remaining material is then sent to secondary treatment. 5. Sediment material is sent to a digester or is incinerated. B. Secondary Treatment - used municipals. 1. Designed to stabilize most organic material & reduce BOD of sewage. 2. Activated Sludge Treatment - sewage is a nutrient for aerobic organisms. 3. Oxygen is applied by mixing sewage in an aerator. 4. Most degradable organic material is then converted into a gas. 5. Bacteria is then food for protozoans. 6. Small increase in organisms & a large decrease in BOD. 7. Microorganisms are then removed by a digester & a portion is left behind to inoculum a new load of wastes. C. Tertiary Treatment 1. Designed to reduce eutrophication. 2. Discard effluent into rivers & lakes (contains large amounts of phospahtes or nitrates). 3. May increase growth of microorganisms & gradually deplete oxygen supply & threaten aquatic life. 4. Certain bacteria (Bacillus, Pseudomonas) are used to removed nitrates & phosphates by denitrification. 5. Chemical are added. 6. Nitrogen is then removed. D. Digester treatment Anaerobically Stabilizes Sewage 1. Anaerobic organisms act of the solids remaining after aerobic treatment. 2. Removes water from the sewage so that a minimum of solid matter remains. 3. Anaerobic organisms produces . Sewage Treatment E. Pathogens May survive During Sewage Treatment. Pathogenic organisms are general removed fro sewage at the secondary treatment, but viruses may survive. 1. Bacteria a. Bacteria are in feces are usually diluted by water in sewage. b. These bacteria must compete with a huge mass of bacteria in secondary treatment that have been adapted to those conditions. c. Most are out . 2. Viruses a. Animal viruses lack appropriate host cells in sewage, although may survive a long time. b. If large quantities are present, may survive after secondary treatment. c. Viruses adhere to , which then can be . VI. Small Scale Treatment A. 1. Sewage is channeled into swallow ponds (lagoons). 2. Stays for to months. a. Setting occurs b. Sewage is stabilized by aerobic &/or anaerobic bacteria 3. Pathogenic bacteria are usually eliminated by competition. B. Tricking Filter 1. Used frequently by smaller treatment plants. 2. Used in place of in secondary treatment. 3. Pebbles & rocks get coated with aerobic microorganisms & aerobically degraded sewage. 2mm thick layer Outer layer - fungi Middle layer Fungi, algae, cyanobacteria Inner - bact., algae, protozoa. C. Septic Tanks 1. Individual dwelling or small communities. 2. Sewage is collected in . 3. Solid wastes settles out & is degraded by anaerobic microorganisms. 4. Fluid overflow (high BOD) - . 5. Depends on aeration & soil (Clay prevent proper function). D. Artificial Wetlands VI. Micro Floral of Water A. Habitat for many different microorganisms Sulfur bacteria, iron bacteria, free-living spiral forms, spore forms B. Water has soil in it so soil habitants are also included microorganisms bacillus. VIII. Testing water Potability Presence of organisms capable of causing disease. A. - any water contaminated with feces contains a pathogen and is therefore considered unpotable Acaule B. Lab Test - by health dept. for fecal contamination 1. test - lactose test (fermented or not) 2. test - Present- small sample. Incubated & if gas is produced, contaminated. 3. test - agar plat 4. - describe gram negative testing C. Membrane filter technique Water Testing IX. Control of water borne diseases A. Coagulation, sedimentation, filtration, & use of chemicals. 1. water. any suspended material from untreated 2. Add (aluminum potassium sulfate). 3. Alum settles out and carries a large amount of bacteria with it. 4. bacteria. the remaining particles & residue 5. is added. B. Swimming Pools Respiratory tract, eye & ear, intestinal tract diseases Athlete foot from damp area - chlorine & bromine C. Drinking fountain direct contact Respiratory area D. Ice Use water Scoops & clan machines E. Sewage Disposal Reduce the amount of Oxygen Demand - Biological Primary Treatment 1. Remove the greater part of solids (Sludge) - flows into a large sedimentation tank. 2. Sent or second tank for anaerobic digestion Turns to acids, methane, and carbon dioxide. 3. Sludge is pumped into open areas for air drying or filtered to remove most of the water. Final can be used as fertilizer or soil conditioner Secondary Treatment Oxidizes all organic material - removing any BOD Accomplished by aerobic breakdown by organisms within flora of sewage waste. Not enough to accomplished this in a reasonable amount of time. 1. Activate Sludge Process Pumps affluent from to a large tank for aeration 2. Trickle Filter Sewage is sprayed over a gravel filter (6 mo. To setup) Aerobic microorganisms attaches to the rocks. 3. Tertiary Treatment Effluent from secondary has a large amount of nitrogen & phosphorus) Removes the reaming amount of nitrogen & phosphorus to prevent algae growth. Septic Tank Only on the surface Exposed to air through a long drain embedded in gravel. X. Microbiology of Solid Wastes A. US million tons / yr from industries, homes. B. Landfills 1 Use near town & communities, cheap. 2. Sanitary a. with each day. b. used for recreation or site development. c. Disadvantages 1. number of sites 2. anaerobic decomposition up to 50 yrs. 3. Produces gas which may lead to explosion if not removed. 4. Pollutants may – heavy metals, pesticides. C. – paper, plastics, Glass, Metals D. 1. Natural decomposition of organic solids. 2. Backyard a. Garden debris, kitchen organic wastes (except meats). b. Place in box with soil & let sit in sun. c. heat kills pathogens leaving nutrients for yard usage. 3. Commercial