front 1 What do you call the clumping together of very fine particles into larger particles (floc) after the addition of a chemical? | back 1 Coagulation |
front 2 WTP operators are mainly concerned with particles that have what type of charge? | back 2 Negative Charge |
front 3 The capacity of water to neutralize acid is called? | back 3 Alkalinity |
front 4 What parameter is measured when water is titrated with 0.2 N H₂SO₄ to a pH of 4.5? | back 4 Total Alkalinity |
front 5 Water color that includes not only the color due to substances in the water but suspended matter as well is called? | back 5 Apparent color |
front 6 Water color of a sample that has had turbidity removed is called? | back 6 True Color Finsene |
front 7 A polymer that has a positive charge is? | back 7 Cationic polymer |
front 8 A polymer that is often used as a filter aid is called? | back 8 Nonionic |
front 9 Where is the filter aid added? | back 9 Filter influent |
front 10 A negatively charged polymer is called? | back 10 Anionic |
front 11 A collection of individual samples obtained at regular intervals, usually every one or two hours during a 24 hour period and combined in proportion to the flow is called? | back 11 Composite sample |
front 12 A contaminant formed by the reaction of disinfection chemicals with other substances in the water being disinfected is called? | back 12 Disinfectant By-Product (DBP) |
front 13 The gathering together of fine particles after coagulation to form larger particles by aprocess of gentle mixing is called? | back 13 Flocculation |
front 14 A single sample of water collected at a particular time and place, which represents the composition of the water only at that time and place, is called? | back 14 Grab sample |
front 15 What test is used to determine the correct chemical dosage during water treatment? | back 15 Jar Test |
front 16 The sum of the atomic weights of the elements in a compound is used to determine? | back 16 Molecular Weight |
front 17 A sample portion of water that is as nearly identical in content and consistency as possible to that in the larger body of water being sampled is called? | back 17 Representative Sample |
front 18 A condition that occurs in tanks or basins when some of the flowing water entering a tank or basin flows along a nearly direct pathway from the inlet to the outlet is known as? | back 18 Short-Circuiting |
front 19 The cloudy appearance of water caused by the presence of suspended and colloidal matter is called? | back 19 Turbidity |
front 20 What parameter is obtained when you measure the optical property of water based on the amount of light reflected by suspended particles? | back 20 Turbidity |
front 21 What are three types of solids found in water? | back 21 Settable, Suspended, and Dissolved |
front 22 When the coagulant sodium aluminate is added to water what happens to the pH? | back 22 pH goes up |
front 23 When aluminum sulfate (alum) is added to the water what happens to the pH? | back 23 pH goes down |
front 24 When the alum dosage is decreased what generally happens with the lime dosage? | back 24 Lime dosage decreases |
front 25 When the alum dosage is increased what normally takes place with the lime dosage? | back 25 Lime Dosage Increases |
front 26 A physical and chemical reaction occurring between the alkalinity of the water and the chemical added which results in the formation of insoluble floc is called? | back 26 Coagulation |
front 27 When using alum as a coagulant, the most effective pH range for the water is? | back 27 5-7 |
front 28 What is the best pH range for coagulation? | back 28 It depends on the coagulant used |
front 29 What water treatment process is known as "flash mix"? | back 29 Coagulation |
front 30 The coagulation process requires what amount of detention time? | back 30 Less than a minute; a few seconds |
front 31 The flocculation process takes place in what length of time? | back 31 5-30 minutes |
front 32 Reducing the speed of the mixers in each succeeding tank to lower the turbulence is called? | back 32 Tapered energy Mixing |
front 33 What type of floc is should be formed during flocculation? | back 33 Discrete and fairly dense (page 115, Vol 1); Popcorn flake (page 117, Vol 1) |
front 34 What is considered the best chemical dosage obtained during coagulation? | back 34 The dosage, which produces finished water that meets drinking water standards at the lowest cost. |
front 35 During the jar test, the floc starts to settle before the mixer is turned off, and 80% of the floc is settled within 1-2 minutes. What does this indicate? | back 35 Overdosage |
front 36 Jar tests are useless unless? | back 36 Applied and Verified |
front 37 During a jar test, the floc starts settling after the mixer is turned off and 80% of the floc settles within 15 minutes. What does this indicate? | back 37 Good Settling/Dosage |
front 38 During a plant tour, the operator notices a small, well-dispersed floc throughout the flow. What action is needed? | back 38 None. This is good treatment. |
front 39 If the operator does not notice a small, well-dispersed floc, what is a likely cause? | back 39 Chemical dosage or feed rate too low; flash mixer not providing effective mixing |
front 40 The WTP is using alum as a coagulant. The floc being formed is tiny. What does this indicate? | back 40 Underdosage |
front 41 In the solids contact unit the water appears to have a bluish tint or milky color. What is the likely cause? | back 41 Overdose of alum |
front 42 As the floc enters the flocculation basin, the size of the floc increases. As it flows through the basin the flow starts to break up. What is the likely cause? | back 42 Flocculator/floc mixer speed to high |
front 43 In question 40, As the floc enters the flocculation basin, the size of the floc increases. As it flows through the basin the flow starts to break up. What is the likely cause? what action is needed to correct the problem? | back 43 Reduce flocculator speed or increase dosage |
front 44 During a plant tour, the operator notices floc flowing over the laundering weirs. What is the likely cause? | back 44 Ans. Floc too light for the detention time produced by the flow
rate |
front 45 In problem 42, During a plant tour, the operator notices floc flowing over the laundering weirs. What is the likely cause? alum is the coagulant being used. The floc is tiny and has a very fine appearance. What is the likely cause? | back 45 Alum Underdosage; Correct by increasing the dosage |
front 46 If alkalinity is an important factor in coagulation, what parameter in the water must the operator measure? | back 46 Alkalinity |
front 47 If the turbidity of the raw water increases, what action is usually taken to ensure good coagulation? | back 47 Increase coagulant dosage |
front 48 When water temperature decreases, what action is needed to ensure good coagulation? | back 48 Increase coagulant dosage |
front 49 In enhanced coagulation, where is the acid added? | back 49 Prior to coagulation |