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85 Cards in this Set
- Front
- Back
When water comes into a unit or tank? |
Influent |
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When water leaves a unit or tank? |
Effluent |
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Where does effluent go after treatment? |
Receiving water |
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B.O.D. (Define) |
Biochemical Oxygen Demand. "Strength" of the wastewater. |
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C.O.D. (Define) |
Chemical Oxygen Demand |
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BOD Test |
Five days at 20*C |
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Samples should be stored at what Temp? |
4*C |
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TSS |
Total Suspended Solids |
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Examples of waterborne diseases |
Typhoid, Cholera, Dysentery, and Hep |
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Waster water is __% Solids and ___% water? |
0.1% Solids 99.9 Water |
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What percentage of solids are dissolved and suspended? |
80% Dissolved 20% Suspended |
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Organic materials contain? |
Carbon |
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Examples of Inorganic Material |
Sand, egg shell, Metals |
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THREE types of Preliminary Treatment (SSG): |
Screening Shredding Grit Chamber |
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Bar Screen v Bar Rack |
Bar Screen= 3/8-2in space Bar Rack = 3-4in gap |
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How are screenings properly disposed of? |
Burning or Burial |
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How is Grit properly disposed? |
Burial at a properly permitted facility |
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Two ways to measure flow/use? |
Flume or a Weir |
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Self-Scouring velocity in gravity sewer: |
2 fps |
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Grit Chambers ideal water velocity: |
1 fps (0.7-1.4 fps) |
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Typical Clarifier velocity range: |
1-2 fps |
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Primary Treatment removes ________ and _____? |
Settable and Suspended |
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Primary Treatment is normally a Physical or Biological process? |
Physical |
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Primary Clarifier Detention Time |
1-2 Hours |
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Secondary Clarifier Detention Time |
2-3 Hours |
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Primary sludge is usually ____ dense than secondary and ____ in color. |
More Dark |
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Secondary sludge is usually ____ dense than primary and is _____ in color. |
Less Lighter |
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Secondary clarifiers are always required to follow a secondary treatment process in order to remove the excess microbes coming from the process. T/F? |
True |
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Water in sludge should be ______ when pumping? |
Minimized |
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Sludge should be pumped often enough to prevent... |
Septic Sludge |
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Sludge should be withdrawn ______.... |
Slowly |
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Coning occurs when an operator draws sludge..... |
Too Quickly |
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What type of disk can be used to check water clarity?
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Sekke Disk |
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Effluent from clarifier passes over what? |
Weir |
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Clarifiers can be sized or rated by three methods: |
Detention Time (Hours) Weir Overflow Rate (GPD/ft) Surface Loading Rate (GPD/ft^2) |
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Primary Clarifiers are not normally used with which Secondary Treatment methods? |
Package Plant Oxidation Ditch Oxidation Pond |
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FOUR main parts of a Trickling Filter |
1. Under-Drain System 2. Retaining Wall 3. Media 4. Distribution System |
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Trickling Filters depend on a straining action for the treatment: T/F |
False |
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Examples of Trickling Filter media: |
Rock, plastic, red wood |
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Trickling Filter media is a consistent size for good air flow through the media: T/F |
True |
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What grows on Trickling Filter media? |
Zoogleal Film |
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What process is a Trickling Filter? |
Aerobic
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How can you increase efficiency of a Trickling Filter plant? |
Add Recirculation |
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Shock Loads are handled better by Activated Sludge or Trickling Filters? |
Trickinly Filters |
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What causes Shock Loads? |
High Flow or High Organic Loads |
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The Distributor Arm dispenses the water through? |
Orifices |
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What powers the Distributor Arm? |
Jet action through orifices
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What is the purpose of a Turnbuckle? |
Level the Distribution Arm |
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Name some problems with a Trickling Filter: |
Ponding Odors Filter Flies Poor Effluent Quality Freezing Sloughing |
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Trickling Filters should remove ___% of BOD. |
75%
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Trickling Filter effluent is slightly ____ and _____ than Activated Sludge. |
Turbid Less quality |
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In the Activated Sludge process the microbes grow _____ in the water column. |
Suspended |
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Activated Sludge must have a DO above what? |
2-4 ppm |
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What organisms are indicators of good, healthy sludge culture? |
Rotifers |
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Mixed Liquor |
Contents of the aeration tank that contains: wastewater, activated sludge, and air. |
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MLSS stands for |
Mixed Liquor Suspended Solids |
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Typical MLSS range |
1000 to 2000 ppm |
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Color of Activated Sludge should be medium to rich _____ ______. |
Dark Brown. |
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Activated Sludge should remove what percentage of BOD? |
90-95%. |
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What is the term for the amount of time sludge in the system before it is waste? |
Sludge Age. |
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Typical Sludge Age for Activated Sludge |
3.5-7.0 Days |
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F/M Ratio |
Food to Microorganism Ratio. |
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The "Y-Wall" promotes... |
Good movement mixing in the aeration tank. |
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Two basic types of sludge Digesters. |
1. Aerobic 2. Anaerobic |
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Normal temperature of an unheated anaerobic digester? |
95*F (Near Body Temp) |
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Anaerobic digesters produce what two gases? |
Methane and Carbon Dioxide. |
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The two groups of bacteria which are necessary to digest sludge in an anaerobic system are: |
Acid Formers and Gas Formers |
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Digester is called 'sour' when? |
It is acidic. |
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Good sludge digestion reduces the volumes of solids by about ____% |
50% |
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What is a well digested sludge called? |
Stabilized. |
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Where can digested sludge be dried? |
Sand Bed. |
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Type of digested sludge dewatering. |
Mechanical Dewatering. |
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Ponds are usually less or more expensive to build and operate? |
Less. |
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What two processes do ponds rely on for aeration? |
Algae and Wind. |
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Typical pond pH permit limits |
6-9 pH. |
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Where do you sample in a pond for performance? |
All FOUR corners. |
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Types of Ponds and their depths. |
1. Aerobic 1-3ft 2. Anaerobic 10 or more ft 3. Facultative 3-5ft |
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Slope of pond levee |
1:2 |
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Maintain how many foot/feet of water to keep emergent weeds from growing in pond? |
3ft. |
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Blue green algae can be controlled with? |
Barley Hay |
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Fences around ponds should have warning signs how often? |
Every 300ft. |
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How can Dikes be damaged? |
Weeds, Burrowing animals, Tree Roots |
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How do you prevent short-circuiting in ponds? |
Building them multi-celled. |
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Nutrient for algae include: |
Nitrogen and Phosphorus |
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If pond is oxygen deficient, what can be added as a short term solution. |
Sodium Nitrate. |