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25 Cards in this Set
- Front
- Back
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What is the purpose of the water seal at base of bearings in a rotary distributor? |
Prevent wastewater leakage from center column (avoid uneven distribution of wastewater over media) |
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Typical detention time for a primary clarifier? |
1.5 - 2 hours |
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Techniques used to eliminate algae from pond effluents? |
Barley straw, constructed wetlands, duckweed systems & overland flow treatment systems. |
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Appearance of healthy activated sludge? |
Brown w/ moderate amount of crisp, white foam |
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How will hypochlorination affect the pH of the wastewater being treated? |
Raise pH |
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What impact does temp have on reaction rate of microorganism in wastewater? |
Doubles w/ every 18 degrees F (until temp is inhibitory) |
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Where is correct location for a vent inside a room storing chlorine? |
Within 12” of floor |
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What is used to control filamentous organisms? |
D.O. & TSS |
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CL Demand Formula |
Demand = Dose - Residial |
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In a healthy pond, what happens if bioflocculation occurs? |
85% removal of both suspended solids & dissolved solids within hours. |
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What temperature should chlorine containers be stored at? |
>50 degrees F |
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Breakpoint Chlorination? |
The addition of chlorine to wastewater until the chlorine demand has been met. |
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What problem might arise from tightening a gland in a pump? |
Wear on shaft or shaft sleeve. |
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How is dissolved oxygen regulated in an oxidation ditch? |
Raising or lowering the ditch outlet level control weir (The greater the submergence of rotors, the more oxygen transferred). |
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What could happen if the volatile acid/alkalinity ratio starts to increase and corrective action not taken immediately? |
CO2 content in the digester will increase |
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Common characteristics of all package aeration plants? |
- Long solids retention time. - High mixed liquor suspended solids. - low F/M ratio |
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What should be done if filamentous organisms become a problem in the mixed liquor? |
Increase DO in aeration tank. |
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What change would likely be made to an activated sludge process in the winter? |
Increase solids under aeration. |
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What is indicated when bubbles are observed coming to pond surface near the inlet? |
Solids that settled to the bottom are being decomposed anaerobically by bacterial action. |
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3 safety requirements for chlorine |
1. SCBA 2. Repair kit 3. Atmospheric monitoring device |
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What color should the mixed liquor in an oxidation ditch be? |
Medium - dark brown - if light brown, sludge wasting rate may be too high. - if solids are thick & color is real dark brown, wasting rate may need to be increased. |
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Controlled discharge ponds w/180 days detention time removal efficiencies. |
BOD 85 - 95% TSS 85 - 95% Caliform up to 99% |
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Maximum holding time for a TSS sample? |
7 days |
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How will algae impact the chlorine demand in the pond effluent? |
Increase the chlorine demand. |
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What is the main purpose of primary treatment? |
To remove substances that readily settle or float |
