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80 Cards in this Set
- Front
- Back
A condition common to lightly loaded, shallow lagoons is |
The growth of filamentous algae and moss
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To reduce odors from a lagoon, an operator may wish to consider |
Aeration and chlorination |
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The performance of a lagoon is influenced by |
Type of soil, depth Surface area, wind action Sunlight, temperatures Characteristics of influent |
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Ponds may be classified according to detention time. A pond with a detention time of less than three days will perform in ways similar to |
A sedimentation process |
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Duckweed |
Impedes sunlight penetration and hinders surface aeration |
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Tests such as DO, PH, and temperature indicate the _________ of a lagoon, while tests such as BOD, coliform and solids indicate the _________ of a lagoon. |
Condition/Efficiency |
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To test a lagoon for PH, dissolved oxygen or temperature, an operator would take |
A grab sample |
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One role of algae in a wastewater stabilization pond is to |
Provide oxygen for other biological life |
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Ideal organic loading for a facultative lagoon system without mechanical aeration is |
50 lbs/acre/day BOD |
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At what time of the day is the D.O. in a lagoon the lowest |
Sunrise |
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BOD is |
Biochemical Oxygen Demand |
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During the day algae _________ the PH of a pond while at night they _________ the PH |
Raise, Lower |
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A submerged inlet to a pond or lagoon |
Minimizes floating material, conserves pond heat |
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What effect does algae growth have on a lagoon during daylight hours |
Increase DO concentration |
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Lagoons are primarily |
Ponds with aerobic and anaerobic character |
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Poor lagoon effluent quality can be caused by |
Low temperatures |
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If the water in your lagoon has a PH of 7.0 it is |
Neutral |
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Most facultative Ponds have an operating depth of |
6-12 ft |
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What effect does temperature have on oxygen solubility |
As temperature increases, solubility decreases |
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The perimeter of a lagoon should be kept of weeds to |
Discourage mosquito breeding and scum accumulation |
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The velocity of the wastewatervthrough a grit chamber should be |
1.0 ft/sec |
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Grit removal involves removing what |
Heavy inorganic waste such as sand or gravel |
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Grease removal in the treatment process is best accomplished in |
Preliminary treatment |
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Comminutors are devices which |
Act both as a cutter or shredder and a screen |
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Two common methods of disposing of screenings are |
Burying and incineration |
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Grit should be removed to |
Prevent wear on pumps and plugging of lines |
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Comminutors are typically included in the treatment process to |
Reduce the size of influent solids |
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The appearance of raw primary sludge should be |
Gray with foul odor |
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Putrefecation occurs when |
Organic matter decays anaerobically |
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Heterotrophs, as opposed to Autotrophs |
Utilize primarily organic sources for energy and reproduction |
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Algae are |
Microscopic plants |
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________ has no effect on the trickling filter process |
Sunlight |
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Bacteria not commonly found in wastewater |
Systolic |
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Bacteria which normally live off dead organic matter are called |
Saprophytic |
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Least common microorganism found in an activated sludge mixed liquor |
Algae |
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Organisms essential to wastewater treatment processes include |
Saprophytes |
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Pathogenic organisms are |
Organisms which cause disease |
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Unpleasant odors at a wastewater treatment plant are generally caused by |
Anaerobic bacteria |
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Before working on a trickling filter you should first |
Shut all flow to unit |
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The main purpose for written standard operating procedures are |
Safety and training |
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When you are concerned with the chemical which you are using at your plant, you should first reference |
MSDS |
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The melting point of the fusible plug on a chlorine cylinder is |
158 - 165 degrees F |
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Oil soaked rags should be |
Stored in a metal container until disposed of Gathered and disposed of ad hazardous material |
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If you encounter a fire near electrical contacts, you should utilize _________ type of fire extinguisher |
Carbon dioxide or halon |
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Whenever you are working on electrical equipment, always |
Work in pairs Make sure you are grounded Turn off the electricity |
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Before entering a confined space or sewer manhole |
Test atmosphere for oxygen deficiency and explosiveness Provide ventilation Have a second person and safety harness ready for use Provide adequate barricades and warning devices around confined space |
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Used to express flow rates |
Cfs |
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The head on the submersible pump sewage lift station is the |
Discharge head plus friction head |
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The formula Flow (gpm) x H (ft) / 3960 (E) is used to calculate |
Water horsepower |
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When replacing packing in a pump, the ________ should be inserted between the rings of packing |
Lantern ring |
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A pump frequently used for handling strong and toxic chemicals is the |
Diaphragm pump |
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Mechanical seals consist of two subassemblies which are |
Rotating ring assembly and the stationary assembly |
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Chlorine reacts with nitrogenous compounds in water to form |
Chloramines |
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Chlorine is chemical that is |
Non-flammable but will support combustion |
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Chlorine is corrosive when combined with |
Moisture |
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Excess chlorine going from your plant to the receiving stream |
Will harm aquatic growth |
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Chlorine is |
A toxic, greenish yellow gas which is 2.5 times heavier then air |
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The purpose for limiting withdrawal rates of gaseous chlorine from 150lbs cylinders is because high rates of withdrawal causes |
Freezing of equipment |
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Repairs to a one ton chlorine cylinder should be made with a |
Class B repair kit |
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Chlorine is used in wastewater for |
Control digester foaming Odor prevention Filamentous control Disinfection |
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Formula for dosage |
Dosage = Residual + Demand |
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Chlorine reduces compounds by |
Oxidation |
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Used to remove chlorine |
Sulfur dioxide |
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When chlorine is added to wastewater, what compounds are formed |
Trichloramine Monochloramine Dichloramine |
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Chlorine feed |
The ejector creates a vacuum that causes the chlorine to be pulled into the solution water |
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Chlorination will |
Reduce BOD |
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How many fusible plugs are found on a one ton chlorine cylinder |
6 |
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The purpose of screening is to |
Remove large objects and debris from influent |
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The purpose of disinfection in wastewater treatment is |
The reduce pathogens |
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The characteristics of wastewater (such as PH, B.O.D.) that is being discharged from a plant are commonly recorded on |
A DMR |
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Nitrifying bacteria are important in treating |
Ammonia |
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The presence of a rotten egg smell is caused by |
Hydrogen sulfide gas |
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Septic is defined as |
A condition produced by anaerobic bacteria |
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A proportional weir is specially designed to |
Have the flow through the weir directly proportional to the head |
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P.O.T.W stans for |
Publicly owned treatment works |
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A buffer is defined as |
A solution or liquid which can neutralize acids or bases |
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Sedimentation is considered a part of |
Secondary treatment |
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Sewers are classified as |
Sanitary, storm, combined |
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Primary clarifiers commonly |
Reduce the BOD |
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PH is measured within a range of |
0-14 |