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36 Cards in this Set
- Front
- Back
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As temperature of water increases what happens to the dissolve oxygen saturation value?
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decreases
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What are compounds of C, H, and O such as starches and sugar, made by green plants, and used as food by other organisms
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Carbohydrates
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what acid is formed when carbon dioxide reacts with water?
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Carbonic acid
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List two ways that phosphorus is removed from wastewater?
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Secondary bio-treatment (anoxic), or use of metal ion coagulants, such as Alum or ferric chloride or lime.
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List two reasons why sulfate is of concern in wastewater
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Because they are responsible for two serious problems, odor and sewer corrosion.
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Bacterial action of free available chlorine is _______ than that of combined available chlorine.
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More
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which of the following chemical substances is most likely to cause corrosion or deterioration of metal and concrete surfaces?
a. K2CR2O7 b. FeCL3 c. CHCL3 d. H2S |
d. Hydrogen Sulfide
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Which one of the following is NOT normally associated with wastewater?
a. CH4 - methane b. CO2 - carbon dioxide c. H2O - water d. H2S - hydrogen sulfide e. Na2SiF6 - sodium silicofluoride |
e. Na2SiF6 - silicofluoride
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What is a major source for formation of hydrogen sulfide?
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Sulfur compounds
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What is sodium aluminate is used for?
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Coagulation and phosphorus removal
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A dechlorinating agent which releases sulfur dioxide is?
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Sodium metabisulfite
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Sodium bicarbonate can be added to which plant process for PH adjustment?
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Alkalinity addition to digester
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Long-chain charged polymers used as coagulants aids are called?
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polyelectrolytes
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What is a strong purple oxidizing agent used for odor control?
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potassium permanganate
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What has skunk scent, sometimes produced in digester, and used as an odor in natural gas?
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methyl mercaptan
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What is a toxic. odorous gas sometimes formed during incomplete break-point chlorination?
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nitrogen trichloride
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Two primary nutrients causing algae and other plant growths in water systems are _________ and _______?
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nitrogen and phosphorus
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To be most reprehensive, a 24-hour composite sample should be collected in ?
a. glass sample bottle in proportion t the flow b. flow-proportional every hour d. every 2 hours with al least 100mls of sample |
b. flow proportional volumes each hour
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Grab samples are considered to be reprehensive of the ---------
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systems conditions at the time the sample was taken
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What three phosphate forms are found in wastewater?
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a. orthophosphate, condensed phosphate and organically-bound phosphates
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What effect does turbidity have on CL2 demand?
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it will increase demand because organisms are harder to penetrate
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The free chlorine residual in water is?
a. the amount of uncombined chlorine remaining in the water after it has had time to react. b. only measured in drinking water samples c. the sum of all measurable chlorine in the water d. total chlorine residual minus the combined demand |
a. the amount of uncombined chlorine remaining in the water after it has had time to react.
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Chlorine is very corrosive when combined with?
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moisture
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Chlorine leaks in metal containers tend to?
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get larger
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The differences between the amount of chlorine added to water and the amount of chlorine remaining at the end of a specified contact period is called the?
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Chlorine demand
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Chloramines are formed by the addition of CL2 and?
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Ammonia
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Generally, tastes and odors may be INCREASE or DECREASED by chlorination?
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Decreased (depends)
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Is chlorine gas DENSER or LIGHTER than air?
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Denser
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The most important use of CL2 in water treatment is?
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Disinfection
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When ccCL2 reacts with nitrogenous compounds in wastewater. what are formed?
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Chloramines
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Lime is general term that stands for two types of chemical.
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Quick lime and hydrated lime
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Another name for quick lime is _________ and ________?
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Calcium oxide and unslaked lime
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Unslaked lime is called?
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Hydrated lime
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What is lime used for?
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Coagulant, PH adjustment
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Lime can effectively remove what nutrient from wastewater?
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Phosphorus
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What is filtrated in a belt press operation?
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It is liquid overflow from a sludge dewatering filter
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