AWWA IMS Mid Year Conference. Chemical Feed. D. Gerard Yates Central Utah Water Conservancy District

Transcription

1 AWWA IMS Mid Year Conference Chemical Feed D. Gerard Yates Central Utah Water Conservancy District

2 The chemical formula for water is: A. HCl B. H 2 O C. 2HO D. HO 2

3 Which of the following chemical compounds is most commonly used as a primary coagulant? A. Al 2 (SO 4 ) 3 14H 2 O (Aluminum Sulfate) B. FeSO 4 7H 2 O (Ferrous Sulfate) C. Fe 2 (SO 4 ) 3 9H 2 O (Ferric Sulfate) D. FeCl 3 6H 2 O (Ferric Chloride)

4 What is the primary purpose of flash mixing? A. To rapidly mix and distribute coagulant chemicals. B. To cause particles in water to agglomerate together. C. To vaporize organic compounds into smaller molecules. D. To cause a chemical reaction in which a compound is converted into another compound. Discussion: Al2(SO4) + 3Ca(HCO3)2 + 6H2O > 3CaSO4 + 2Al(OH)3 + 6H2CO3 (alum) (alkalinity) (floc) (carbonic acid)

5 When using alum, what is the preferred ph range for coagulation? A B C D (Ferric )

6 1. Which is a chemical compound? A. Cu B. NaCl C. Fe D. Al

7 2. Mud, silt, clay and other suspended matter in water that causes it to appear murky is called: A. Cloudiness B. Turbulence C. Hardness D. Turbidity

8 3. When alum is added to water, a chemical reaction occurs in which dissolved sulfate (1), alkalinity (2) and ph (3) A. (1) Increases, (2) Increases, (3) Increases B. (1) Increases, (2) Decreases, (3) Decreases C. (1) Decreases, (2) Decreases, (3) Decreases D. (1) Explodes, (2) Turns Laterally, (3) Sinks

9 4. Particles in water usually carry a negative electrical charge. In water treatment, this natural repelling electrical force is called. The Force is strong enough to hold the very small, colloidal particles apart and keep them in suspension. A. Zeta Potential B. Oxidation C. Cholorination D. Van der Waal

10 5. What is the opposite of Zeta Potential? Van der Waal

11 6. Which of the following will affect the coagulation/flocculation process? A. Type of coagulant, THM s, ph, amount of coagulant used. B. Raw water quality, hardness, zeta potential, temperature. C. Amount of coagulant used, type an length of flash mixing, type and length of flocculation, type of coagulant used. D. Reservoir level, other chemicals used, alkalinity, ph, color.

12 7. Coagulation is a physical and chemical reaction that occurs between the coagulant added and the of the water. A. Turbidity B. Residual C. Alkalinity D. Both A & C

13 8. Which laboratory test is performed to indicate optimum chemical dosage for coagulation? A. DPD Test B. Jar Test C. Marble Test D. D.O. Test (marble: precipitation potential for calcium carbonate) (picture)

14 Jar test

15 10. Even though flash mixing cannot be directly observed, which of the following is an indicator of inadequate mixing? A. Fish eyes B. Very small floc C. Frequent backwashing D. All of the above

16 11. Floc that remains suspended longer than in a jar test will probably not settle out in the sedimentation basin, and will increase the load on the filter. A. 5 to 10 seconds B. 1 to 2 minutes C. 15 to 20 minutes D. 5 to 10 hours

17 12. What is flocculation? A. The slow stirring process that causes the gathering together of small particles into larger particles. B. The destabilization process where charges on particles are neutralized and become separate from each other. C. A Treatment process were a tank is filled and a chemical solution is prepared. D. A process in which solid particles settle out of solution to the bottom of the basin. (See picture)

18 Flocculation

19 13. What is the most important consideration in coagulation and flocculation control? A. ph adjustment B. Selection of type and amount of coagulant chemical to be applied. C. Good recordkeeping to comply with drinking water regulations. D. Visual observations of the flocculation and sedimentation process.

20 14. Which of the following are common laboratory tests used to monitor the coagulation and flocculation process? A. Chlorine Demand B. ph C. Alkalinity D. Temperature E. Turbidity

21 15. Why do treatment plants need to monitor ph and turbidity? A. To calculate the removal rate of trihalomethanes B. To know when the Langlier index needs adjusting C. To calculate filter loading rates D. Changes in raw water quality

22 16. Which chemical compound is used to increase the alkalinity and ph in water treatment to improve the coagulation process? A. Lime B. Alum C. Potassium permanganate D. Calcium oxide

23 17. What is a coagulant aid? A. A chemical used to improve the performance of a coagulant. B. A chemical that will boost the molecular density of a coagulant. C. A chemical used to fight infection in a coagulant. D. A chemical that will determine the amount of coagulant to use.

24 18. Which of the following chemicals is not commonly used to raise the alkalinity of water and thereby improve flocculation? A. Lime B. Soda ash C. Caustic soda D. Alum

25 19. The turbidity of your raw water changes from 50 to 300 NTU s. What steps should you take? A. Increase detention time B. Increase alum feed rate C. Increase filter run length time D. Increase chlorination

26 20. The colder the water the faster chemicals will react. A. True B. False

27 21. Temperature, ph, alkalinity, and turbidity all have an effect on the coagulation process. A. True B. False

28 22. The amount of chemical used during the coagulation process in a conventional water treatment filtration plant has no effect on the filtration process. A. True B. False

29 23. Coagulation and flocculation may remove materials causing tastes and odors from water by adsorption and/or trapping of materials within the floc. A. True B. False

30 24. One of the most important advantages of ferric chloride (iron salts), over alum is that iron salts will coagulate over a border ph range. A. True B. False

31 25. Polyelectrolytes (compounds with long-chain molecules) are used effectively as coagulants, coagualant aids, and filter aids. A. True B. False

32 26. Of the three polyelectrolyte classifications which one produces positively charged ions? A. Anionic B. Cationic C. Nonionic

33 27. Which of the three polyelectrolyte classifications produces negatively charged ions? A. Anionic B. Cationic C. Nonionic

34 28. Which one of the following chemicals, if added at higher feed rates than needed, would most likely increase the head loss on a filter? A. Anionic polymer B. Chlorine dioxide C. Caustic soda D. Potassium permanganate

35 29. During the coagulation /flocculation process, floc that is too small may be caused by: A. High turbidity B. Low flow conditions C. Improper coagulation dosage D. High levels of organic material

36 30. What is the advantage of optimizing chemical coagulant doses? A. Excessive sludge produced B. Short filter runs C. Reduced chemical costs D. Poor disinfection

37 31. What happens when a paddle wheel flocculator is operated at a speed slower then desirable? A. Floc settles out prematurely B. Floc particles break-up C. Decrease in the height of the sludge blanket D. Formation of floc particles

38 32. The flocculation compartments are separated by baffles to prevent of the water being treated. A. Sedimentation B. Short-circuiting C. Headloss D. Sludge

39 33. What is a cause of floc that is too small? A. Colder water temperatures B. Flow surges through the plant C. Excessive calcium carbonate compounds D. High levels of aluminum sulfate

40 Studies on pre-chlorination practices point out that the interaction of chlorine with organic matter in raw water forms? Chlorine + Organics = Disinfection By-products

41 What should an operator use when working on chlorine leaks within a confined space where oxygen can be displaced?

42 Which of the following is not a chemical commonly used to disinfect public drinking water? Chlorine Chlorine dioxide Iodine Chloramines Ozone

43 Operational control tests used to monitor the disinfection process are: Chlorine Residual Temperature ph Hardness Color

44 Chlorine gas is times heavier than air. A lot

45 If your samples show that the water in the distribution system is highly corrosive, what should you do? Decrease the ph Increase the ph Run really fast Look for a new job

46 The purpose in practicing breakpoint chlorination is to: Breaking point where the addition of more chlorine does not decrease the free chlorine residual additional chlorine is not consumed or converted: (Iron, manganese, organics, ammonia, nitrates or converted from monochloramine > dichloramine > trichloramine )

47 What should you do for a victim that has been exposed to large amounts of Chlorine?

48 What is used to detect chlorine leaks? Chlorine Detector Ammonia

49 What is the primary source of coliforms in a water supply? WarmBlooded Animals

50 Calcium hypochlorite is formed as a. Powder

51 Why is the turbidity of the water a concern when using chlorine? Chlorine only comes in contact with the outer surface of a particle. Chlorine Demand

52 An operator is caught in a room where chlorine gas is leaking. If the operator does not have a mask, what should the operator do? Don t Get Down Remember chlorine is 2.5 times heavier than air.

53 After a reservoir has been entered for maintenance, it must be disinfected prior to being placed into service. Procedures for this process are given in what standard? AWWA Standard C652-11

54 A chlorine residual in water can be determined by using the reagent: DPD Or N,N-diethyl-p-phenylenediamine

55 Why do water systems test for coliform bacteria? Indicates that Water is Biologically Safe Most pathogens are less resistant to chlorine than coliform bacteria

56 Sodium hypochlorite is usually (a) percent available chlorine and calcium hypochlorite is usually (b) percent available chlorine. NaOCl = 15% Ca(OCl) 2 = 65%

57 is used to indicate the rate of gas flow on a chlorinator. Rotameter

58 What should an operator do if customers complain of swimming pool odor?

59 The (a) color and (b) odor characteristics of chlorine gas are:

60 One volume of liquid chlorine can evaporate and produce volumes of chlorine gas.

61 Chlorine cylinders are filled to percent capacity %

62 What will influence the point of application when using chlorine? Disinfection By-Products Biological Control Pre-chlorination / Pre-treatment Post chlorination CT requirements

63 By continuously withdrawing chlorine, how many lbs/day can be withdrawn safely from a (a) 150 lb. cylinder and from a (b) ton container at room temperature without the line freezing? A) 42 lbs/day B) 400 lbs/day

64 What effect does the addition of chlorine gas to water have on the water s ph? Hydrochloric Acid will decrease the ph

65 An alternative disinfectant that could be used to avoid the formation of THMs is: Chlorine Dioxide Chloramines Ozone

66 Algae can cause problems of: A. Filter clogging B. Taste and odors C. Slime growth D. All of the above Note: See picture next slide

67 Algae that affect drinking water quality

68 When is the most likely season for algal blooms? A. After fall or spring turnover. B. After the decay of calcium carbonate compounds C. During the winter turnover. D. During the summer equinox

69 What is the (a) common and (b) nickname for CuSO 4? A. (a) copper sulfate, (b) blue stone B. (a) calcium hypo., (b) Quick lime C. (a) aluminum sulfate, (b) Alum D. (a) Polymer, (b) fish eyes Note: See sample

70 Which chemical is used to treat reservoirs and lakes with algal blooms? A. Alum B. Copper sulfate C. Ferric chloride D. Polymer

71 A heavy growth of algae in a surface water reservoir will have which one of the following effects on the water? A. Lower the ph B. Raise the ph C. Will have no effect on the ph D. Increase ph acid and lower ph basic Note: ph discussion (next slide) less light, less DO, less plants, ٨ temp, ٨ ph, ٨ CO 2

72

73 Water that is high in sulfate can cause: A. Diarrhea B. Hardening of the arteries C. Mottling of tooth enamel D. Staining of plumbing fixtures > 1000 mg/l

74 Travelers from one community to another can become ill, even if drinking water meets health standards. The digestive tract may be disturbed by changes in the. A. Coliform bacteria count B. Filtration rate C. ph value and mineral content D. Amount of chlorine

75 Which word best describes the chemical combination of substances in solution so as to cause separation in the insoluable form? A. Stabilization B. Saturation C. Precipitation D. Coagulation

76 Iron and manganese react with form insoluble compounds. to A. Hydrogen sulfide gases B. Calcium carbonate compounds C. Alkalinity D. Dissolved oxygen

77 Iron and manganese problems generally occur in systems that draw water from either deep wells or from the lower levels of large reservoirs because? A. Soluble forms of these minerals reach much higher concentrations under anaerobic conditions. B. Iron and manganese can combine with THMs C. Hydrogen sulfide is mixed with these minerals and causes taste and odor problems. D. Decomposition of organic matter with iron and manganese forms troublesome constituents.

78 Primary water quality variables that an operator should be concerned about include: A. Harness and corrosion B. Turbidity and chlorine residual C. Tastes and odor D. All of the above.

79 Hydrogen sulfide in water causes the water to have and odor similar to: A. Rotten wood B. Ammonia C. Rotten eggs D. Potassium permanganate

80 If taste and odor problems develop, what do you look for? A. Iron metabolites B. The presence of trouble causing algae or diatoms C. Lack of free alum residual D. The turbidity in the raw water compared to the turbidity in the finished water.

81 Tasted and odor in surface waters can be caused by the growth of aquatic organisms and the decomposition of organic matter. Water that is devoid of oxygen will also produce very offensive odors which are caused by: A. Anaerobic bacteria B. Chloroorganic compounds C. Humic substances D. Iron and magnesium

82 Activated carbon is used to reduce: A. Alkalinity B. Tastes and odors C. Hardness D. ph

83 What is the name of the process of how activated carbon works: A. Adsorption B. Absorption C. Coagulation D. Electolysis

84 The most common chemical used for tastes and odor control in drinking water is: A. Potassium permanganate (KMnO 4 ) B. Powdered Activated Carbon (PAC) C. Aeration (O 2 ) D. Chlorine (Cl 2 )

85 Which of the following treatment chemicals could be effective oxidants useful in the control of taste and odor problems: A. Chlorine, potassium permanganate, ozone, granular activated carbon B. Granular activated carbon, powdered activated carbon, ozone, chlorine C. Potassium permanganate, chlorine dioxide, powdered activated carbon, ozone D. Chlorine, potassium permanganate, ozone, chlorine dioxide

86 A step in determining the Threshold Odor Number (TON) of water is to: A. Count the number of odor-producing organisms present B. Dilute the sample with distilled alcohol C. Dilute the sample with odor-free water D. Count eh number of odor producing complaints from consumers

87 Threshold odor # (TON) tests are conducted at what temperature A. 10 degrees Celsius B. 60 degrees Celsius C. 100 degrees Celsius D. 20 degrees Celsius

88 1. Which of the following has no influence on the corrosion process: A. Dissolved gases B. Bacteria C. Temperature D. Protozoans

89 Corrosive waters can be the result of the presence of: A. Acids B. Calcium C. Magnesium D. Organic material

90 Which of the following is not a problem related to corrosive water? A. Tuberculation B. Rusty water C. Electrolysis D. Leaks E. They are all problems

91 What is the opposite of aggressive or corrosive water? A. Electrolysis B. Oxidation C. Saturation D. Scaling

92 Which of the following conditions when found in a water supply, would increase the corrosiveness of the water on metal? A. High alkalinity B. High dissolved CO 2 C. Low dissolved oxygen D. Low dissolved mineral content

93 Cathodic protection means protection against for metal surfaces. A. Cathodes B. Corrosion C. Scaling

94 7. What are the two common minerals that contribute to the hardness of water: A. Aluminum and iron B. Potassium and magnesium C. Calcium and magnesium D. Iron and manganese

95 8. Black stains on plumbing fixtures might be attributed to: A. Magnesium B. Manganese C. Carbon D. Copper

96 Iron in water can cause: A. Staining of plumbing fixtures B. Staining of clothes washed in water C. The water to have a bad apperance and tastes D. All of the above

97 Which element can cause red water complaints in a water distribution system? A. Aluminum B. Copper C. Iron D. Manganese

98 Hardness is expressed in what terms: A. ppm as CO 2 B. mg/l as CaCO 3 C. ppb as Ca D. mg/l as CaH 2 S

99 In order for water to be considered soft it should be at which level of hardness (CaCO 3 )? A. 50 mg/l B. 100 mg/l C. 150 mg/l D. 300 mg/l A)

100 Scaling deposits of calcium carbonate (CaCO 3 ) will accumulate more rapidly and in greater volume in water. A. Hot B. Cold C. Rain D. Lake

101 Plotting the ph and alkalinity on the Baylis curve or Langlier Index is used to detect: A. Noncarbonated hardness B. Van der Waals force C. ph saturation D. Corrosiveness

102 15. A water that indicates a negative number on the Langlier Index usually is: (Hint: Langlier Index (LI) = ph ph s s=saturation) A. Scaling B. Hard C. Polluted D. Corrosive Langlier Index Negative (-) Positive (+) Corrosive or Aggressive Neutral Scale Forming Note: Anything above positive 1 should be considered highly scale forming. Anything below negative 1 should be considered highly corrosive or aggresive

103 16. If the ph of the water being delivered into the distribution system exceeds the ph at saturation by 0.5 or more, what most likely will occur? A. Corrosion will be initiated B. Scale formation C. Neutral water D. Aggressive water

104 What is the purpose of calculating the Langlier Index and using coupons in the distribution system? A. They are used to determine the cost of the system. B. They are used to analyze the softening effect of the water on clothes. C. They are used to evaluate the stability of water. D. They are used as analytical tests to determine phosphate concentration.

105 Which of the following is not a method for controlling scale formation or corrosion? A. ph and alkalinity adjustment with lime B. Chelation C. Sequestering D. Langlier Index (this is not a method, it is only and indicator of water quality)

106 What is calcium carbonate saturation used for? A. Corrosion control B. Alum control C. Chlorine control D. Algae control

107 Name a chemical used to help resist corrosion in the distribution system: A. Calcium hydroxide [Ca(OH) 2, also called Hydrated lime] B. Sodium hydroxide [NaOH, also called caustic soda] C. Polyphosphate compounds D. All of the above

108 Polyphosphates are used for iron retention. A. True B. False

109 What method is usually used to reduce iron deposition of distribution pipes? A. Flushing the main lines B. Polyphosphate treatment at the source of supply C. Pumping high rates of water D. Both A and B

110 A corrosion caused by contact of two different metals is called? A. Metal corrosion B. Galvanic corrosion C. Hydraulic corrosion D. Erosion corrosion

111 If a copper line and a galvanized line are connected together and the ground is moist, which of the following would most likely occur first? A. The copper line would corrode B. The soil will turn red C. The galvanized line would corrode D. Calcium carbonate scaling will for on the galvanized line

112 The most important factor affecting the useful life of piping is: A. The ability of the material used to resist internal and external corrosion B. The depth of the pipe C. The flexibility of the pipe D. The smoothness of the inside of the pipe of C factor

113 What is the effect of water having low hardness on metallic pipes? A. The water is extremely corrosive B. It will cause fewer losses of head during pumping C. The water will start scaling D. No effect at all

114 What parameters can be used to monitor the stabilization process? A. ph and alkalinity B. D.O. and TDS C. Temperature and calcium carbonate content D. Pipe and coupon testing E. All of the above (be aware of all of these as possible answers).

115 If a finished water is shown to be highly corrosive, what can the drinking water system do to control it? A. Increase fluoride dosage B. Increase polymer dosage C. Increase ph D. Increase sludge removal

116 29. What is the usual purpose for adding soda ash to a raw water supply? A. To reduce the non-carbonate hardness B. To reduce chlorine residual C. To increase the sodium content D. To increase the turbidity

117 Meniscus

118 What is the name of the process of mixing an acid and a base called? A. Equalization B. Coagulation C. Neutralization D. Presence/absence

119 Which laboratory test is performed to indicate the optimum chemical dosage for coagulation? A. DPD test B. Jar test C. Marble test D. D.O. test

120 Which test is normally used for determining the fluoride concentration of treated water? A. Marble B. NTU C. SPADNS

121 The ph scale runs from (a) and (b) is considered to be neutral A. (a) 0 10, (b) 5 B. (a) 0 14, (b) 7 C. (a) 1 14, (b) 10 D. (a) , (b) 100 ph Scale Acidic Neutral Basic

122 A ph reading of 6.0 in raw water indicates the sample is: A. Acidic B. Alkaline C. Basic D. Neutral

123 Which of the following numbers would indicate a basic ph sample? A. 2 B. 4 C. 6 D. 8

124 The chemical formula for calcium carbonate is: A. CaCO 3 B. CuSO 4 C. NaCl D. NaCO

125 The condition in infants know as methemoglobinemia (Blue Baby Syndrome) is thought to be caused by high concentrations of what contaminate: A. Boron B. Phosphate C. Nitrate D. Fluoride

126 The indicator methyl orange is used to test for: A. Alkalinity B. Chlorine residual C. ph D. Total Hardness

127 Sulfuric acid (H 2 SO 4 ) is used as the titrant for what chemical test? A. Alkalinity B. Chlorine residual C. Fluoride D. Sulfate

128 The titrant used in performing a hardness test is: A. SPADNS B. Buffer solution of ph 7.0 C. Sodium thiosulfate D. EDTA

129 If your results show a concentration of 450 mg/l of alum in the finished water, you should first: A. Feel satisfied that you have achieved maximum alum levels B. Increase the dosage C. Check the calculations and or rerun the test D. Reduce alum feed rate

130 The chemical symbol C stands for: A. Calcium B. Carbon C. Chlorine D. Copper

131 Which of the following is an example of an inorganic contaminant that could be found in a water sample what would be a threat to human health? A. Arsenic B. Chromium C. Cadmium D. Lead E. Mercury F. Selenium G. All of the above (all of the above are examples of inorganics that are potential health hazards)

132 Which of the following is an example of a volatile organic chemical? A. Giardia lamblia B. Lead C. Trichloroehylene D. Nitrate (NO 3 )

133 What is the MCL for fluoride? A. 6.0 mg/l B. 4.0 mg/l C. 1.0 mg/l D. 2.0 mg/l

134 To achieve maximum benefits of fluoridation, what is considered the optimal concentration? A. 0.1 mg/l B. 1.0 mg/l C. 2.0 mg/l D. 4.0 mg/l Note: the MCL for fluoride is 4.0 mg/l and SMCL is 2.0 mg/l.

135 The End QUESTIONS????????????