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17 Cards in this Set
- Front
- Back
2 Reasons for
Water Treatment (sewage) |
1. Prevent disease transmission
2. Reduce amount of organics |
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What happens if aquatic microbes use aerobic respiration?
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The water becomes aerobic (almost no dissolved oxygen) which means death by suffocation of fish & shelfish
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What is produced by anaerobic microbes that use fermentation or anaerobic respiration?
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Smelly gases
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_________ is a sulfate reducing bacteria that produces SO4 to _____ by aerobic respiration (to get a rotten egg smell).
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Desulfovibrio & H2S
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_________ Treatment: physically separates "biosolids" from dissolved & suspended organics.
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Primary
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In Primary Treatment, how much of the organics can be removed?
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30-40%
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What does Secondary Treatment do?
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Treats water from Primary Treatment
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What are the 2 goals of Secondary Treatment?
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Goal 1: Rapid conversion of organic carbon to CO2 gas
Goal 2: Reduce pathogens |
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What does Secondary Treatment rely on in converting organic carbon to CO2 gas?
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It relies on microbes to do aerobic respiration which turns the organics/sugars/etc into CO2
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For the rapid conversion of organic carbon to CO2 in Secondary Treatment to be successful, we need lots of _______ to reduce organics by _______ in a few hours.
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oxygen & 90-95%
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It's possible that the microbes (in Secondary Treatment) can sometimes be killed. This means that the organics cannot get decomposed. What is an example a microbe-killing substance?
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Toxic Chemicals (ex:// too much disinfectant flushed down a toilet)
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In Secondary Treatment, how do we get oxygen to the microbes? (2 ways)
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1. Activated Sludge Tanks which use injections of compressed air
2. Use of a Trickling Filter |
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Describe a Trickling Filter
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Water is sprayed from rotating arms (booms) and then flows over a deep bed of rocks (traditionally), as it trickles on the rocks, it picks up oxygen and microbes will colonize on the rocks using slime layers and then they break down organics aerobically
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In Secondary Treatment, the reduction of pathogens occurs where?
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In the Activated Sludge Tank and Trickling Filter
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What are the 3 ways of reducing pathogens in Secondary Treatment?
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1. Flocculation
2. Predation 3. Competition |
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Describe Flocculation
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Organic balls of goo & microbes (sticky balls) "floc" like biosolids; they sink to the bottom removing pathogens from water
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Describe Predation
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Preying on other microbes- especially protozoans, they prey on bacteria
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