TEST YOUR KNOWLEDGE
Electrodeionization Water Treatment Training Level: Advanced
To test your proficiency on the topics covered in this seminar, 25 questions are provided. The questions cover the major concepts participants learn in this seminar.
1. Mg+2 is a(n):
a. Cation b. Anion c. Positron d. Neutron
2. Mg+2 is one of the major contributors to:
a. Hardness b. Alkalinity c. pH d. None of the above
3. What is the main form of CO2 at a pH of 4?
a. Dissolved CO2 (H2CO3 = Carbonic Acid) b. HCO3- (Bicarbonate Ion) c. CO3-2 (Carbonate Ion) d. None of the above
4. What is the main form of CO2 at a pH of 7?
5. What is the main form of CO2 at a pH of 10?
6. RO membranes remove which of the following the best?
a. Single charged ions b. Double charged ions c. Triple charged d. All of the above are removed the same amount
7. The most common scaling compound is:
a. Calcium carbonate (CaCO3) b. Calcium sulfate (CaSO4) c. Calcium chloride (CaCl2) d. None of the above
8. The high pH in areas where hydroxide ions (OH-) are present will cause the CO2 in solution to:
a. Fizz b. Off gas c. Change into carbonate ions d. All of the above
9. RO membranes reject which of the following organic compounds the best?
a. CH4 b. CH3OH c. C2H5OH d. None of the above
10. As long as an upstream RO membrane is operating correctly, there is no worry of chemical attack of EDI membranes.
a. True b. False
11. What is the purpose of Ion exchange resin in the concentrating compartment in some EDI’s?
a. Lower overall stack resistance b. Reduce the need for brine injection c. Reduce the need for concentrate recycle d. All of the above
12. Which gas(es) is(are) produced at the cathode?
a. Hydrogen b. Oxygen c. Chlorine d. a, b correct e. b, c correct f. a, b, c correct g. No gases are produced
13. Which gas(es) is(are) produced at the anode?
14. If there is more resistance in a direct current circuit, what has to happen to voltage in order to produce the same current?
a. Increase b. Decrease c. Stay the same d. Voltage has no impact
15. If the voltage is increased in a direct current circuit, what will happen to current if the resistance stays the same?
16. What changes would cause you to have to supply more voltage to an EDI unit in order to make the same quality of product water?
a. Colder feed water b. Higher dissolved substances concentration in the EDI unit feed water c. Scaling of ion exchange resin beads and/or membrane sheets d. Organic fouling of ion exchange resin beads and/or membrane sheets e. Higher EDI feed water flow rate f. None of the above g. a – f correct
17. What is the purpose of injecting sodium chloride into the concentrate channel feed water?
a. Decrease voltage requirement b. Increase current flow c. Decrease resistance to current flow d. None of the above e. a, b, c correct
18. What is the purpose of recirculating a portion of the concentrate channel water?
19. Scaling is mainly caused by single charged ion pairs.
20. The current drops in an EDI unit. Which of the following could cause this?
a. Lower feed conductivity b. Lower feed water temperature c. Lower voltage d. Scaling e. Fouling f. Chemical attack g. a & b h. a, b, c, & d i. b – f j. a - f
21. Salt is seen building up on the outside of an EDI unit. This is:
a. Normal, of no concern b. Dangerous, could lead to shorting c. Neither a nor b d. Both a and b
Use the following process flow diagram (PFD) to answer 22-25.
22. The EDI unit is scaling. What are some possible causes given this PFD?
a. Multimedia filter malfunction b. Softener malfunction c. Activated carbon malfunction d. UV malfunction e. Cartridge filter malfunction f. RO malfunction g. b & e h. b & f i. d & f j. None of the above
23. The EDI unit is fouling with particles. What are some possible causes given this PFD?
a. Multimedia filter malfunction b. Softener malfunction c. Activated carbon malfunction d. UV malfunction e. Cartridge filter malfunction f. RO malfunction g. a & e h. b & f i. d & f j. None of the above
24. The EDI unit is fouling with organics. What are some possible causes given this PFD?
a. Change in feed water to plant b. Multimedia filter malfunction c. Softener malfunction d. UV malfunction e. Cartridge filter malfunction f. RO malfunction g. a & e h. a, b & f i. a & f j. None of the above
25. The EDI resin is chemically attacked. What are some possible causes given this PFD?
a. Multimedia filter malfunction b. Softener malfunction c. Activated carbon malfunction d. UV malfunction e. Cartridge filter malfunction f. a & e g. b & d h. d & e i. None of the above