TEST YOUR KNOWLEDGE
Advanced Water Treatment Training Level: Advanced
To test your proficiency on the topics covered in this seminar, 20 questions are provided. The questions cover the major concepts participants learn in this seminar.
MMF = Multimedia filter CF = Cartridge filter RO = Reverse osmosis NaOH = Sodium hydroxide (caustic) EDI = Electrodeionization MB IX = Mixed-bed ion exchange UV = Ultraviolet irradiation UPW = Ultra-pure water Memb Degas = Membrane degasification UF = Ultrafiltration
NOTE: Use the above Process Flow Diagram (PFD) to answer the following questions.
1. What problem(s) can the city’s significant overfeed of alum cause in the UPW plant’s equipment?
a. MMF fouling b. Heat exchanger fouling c. CF fouling d. First pass RO unit fouling e. Second pass RO unit fouling f. EDI unit fouling g. a. & b. h. c. & d. i. d. & f. j. e., f. & g. k. All of the above l. None of the above
2. What problem(s) can the city’s overfeed of cationic polymer cause in the UPW plant’s equipment?
3. What problem(s) can the city’s significant overfeed of lime cause in the UPW plant’s equipment?
a. MMF scaling b. Heat exchanger scaling c. CF scaling d. First pass RO unit scaling e. Second pass RO unit scaling f. EDI unit scaling g. a. & b. h. c. & d. i. d. & f. j. e. & f. k. All of the above l. None of the above
4. What problem(s) can the city’s overfeed of ammonia and chlorine cause in the UPW plant’s equipment?
a. MMF performance degradation b. Heat exchanger performance degradation c. CF performance degradation d. First pass RO unit performance degradation e. Second pass RO unit performance degradation f. EDI unit performance degradation g. a. & b. h. c. & d. i. d. & f. j. e. & f. k. All of the above l. None of the above
5. What problem(s) can occur with a significant loss of acid injection in the UPW plant?
a. CF scaling b. First pass RO unit scaling c. Second pass RO unit scaling d. EDI unit scaling e. MB IX scaling f. 185 nm UV scaling g. a. & b. h. b. & c. i. b. & d. j. b., d., & e k. All of the above l. None of the above
6. What problem(s) can occur with a significant loss of scale inhibitor injection in the UPW plant?
a. CF performance degradation b. First pass RO unit performance degradation c. Second pass RO unit performance degradation d. EDI unit performance degradation e. MB IX performance degradation f. 185 nm UV performance degradation g. a. & b. h. b. & c. i. b. & d. j. b., d., & e k. All of the above l. None of the above
7. In which piece of equipment will a significant loss of sulfite injection in the UPW plant likely show up first as a performance problem?
a. CF b. First pass RO unit c. Second pass RO unit d. EDI unit e. MB IX unit f. 185 nm UV unit g. All of the above will show performance losses at the same time h. None of the above
8. The effluent quality of which piece(s) of equipment will drop with a significant loss of NaOH injection in the UPW plant?
a. Second pass RO unit b. EDI unit c. MB IX unit d. 185 nm UV unit e. a. & b. f. a., b., & c. g. b. & c. h. c. & d. i. All of the above will show performance losses at the same time j. None of the above
9. What is(are) the primary purpose(s) of injecting NaOH in front of the second pass RO unit?
a. First pass RO permeate pH is low and can damage downstream equipment? b. Decrease the damage from any chlorine compounds passing through the first pass membrane c. The addition of Na increases the rejection characteristics of the second pass RO membrane and provides better permeate quality d. The addition of OH increases the rejection characteristics of the second pass RO membrane and provides better permeate quality e. a. & b. f. a. & c. g. a. & d. h. b. & c. i. All of the above j. None of the above
10. What would be the impact(s) of injecting NaOH in front of the first pass RO unit instead of between the passes?
a. This would work for most feed waters but isn’t common because injecting between passes uses less NaOH and is therefore cheaper. You’re only treating the first pass permeate stream, not the feed stream. There is less water to treat. b. This would work for most feed waters because the addition of Na increases the rejection characteristics of the RO membrane and provides better permeate quality c. This wouldn’t work because the NaOH and scale inhibitor injections are not compatible d. This wouldn’t work because the NaOH and sulfite injections are not compatible e. a. & b. f. c. & d. g. All of the above h. None of the above
11. If the RO units are passing more CO2, what will happen to the polishing bed portion of the EDI unit?
a. Becomes smaller b. Loads up with sodium ions associated with CO2 c. Becomes larger d. Loads up with chloride ions associated with CO2 e. a. & b. f. c. & d. g. All of the above h. None of the above
12. What can cause boron to break through a mixed-bed ion exchange unit fed directly with second-pass RO permeate?
a. pH, because except at very low pH levels boron is non-ionic b. The cation exchange resin overloads with boric acid c. pH, because except at very high pH levels boron is non-ionic d. The anion exchange resin overloads with boric acid e. a. & b. f. c. & d. g. All of the above h. None of the above
13. The influent to the 185 nm UV unit has the following characteristics:
Resistivity = 18.2 Megohm-cm; TOC = 10 ppb; Bacteria = 3 cfu/100 mL; Oxygen 4 ppm. The effluent of the 185 nm UV unit will likely have: a. Lower resistivity b. Lower TOC concentration c. Lower bacterial count d. Lower oxygen concentration e. Only 1 of the above (a. – d.) is correct f. Only 2 of the above (a. – d.) are correct g. Only 3 of the above (a. – d.) are correct h. All 4 of the above (a. – d.) are correct i. None of the above is correct
Resistivity = 18.2 Megohm-cm; TOC = 10 ppb; Bacteria = 3 cfu/100 mL; Oxygen 4 ppm. The effluent of the 185 nm UV unit will likely have:
a. Lower resistivity b. Lower TOC concentration c. Lower bacterial count d. Lower oxygen concentration e. Only 1 of the above (a. – d.) is correct f. Only 2 of the above (a. – d.) are correct g. Only 3 of the above (a. – d.) are correct h. All 4 of the above (a. – d.) are correct i. None of the above is correct
14. What is the primary purpose of the 254 nm UV unit located just downstream of the UPW Tank?
a. Kill bacteria b. TOC reduction c. Removal of oxygen d. Removal of silica e. None of the above
15. What is the primary purpose of the nitrogen-purge membrane degasification unit?
a. Remove carbon dioxide from the influent water b. Remove nitrogen from the influent water c. Add nitrogen to the influent water d. Remove oxygen from the influent water e. None of the above
16. A no-purge membrane degasification unit will:
a. Remove carbon dioxide from the influent water b. Remove nitrogen from the influent water c. Add nitrogen to the influent water d. Remove oxygen from the influent water e. Only 2 of the above (a. – d.) are correct f. Only 3 of the above (a. – d.) are correct g. All 4 of the above (a. – d.) are correct h. None of the above is correct
17. The influent to the 254 nm UV unit located just downstream of the UPW Tank has the following characteristics:
Resistivity = 17.8 Megohm-cm; TOC = 1 ppb; Bacteria = 3 cfu/L; Oxygen 4.2 ppm. The effluent of this UV unit will likely have: a. Lower resistivity b. Lower TOC concentration c. Lower bacterial count d. Lower oxygen concentration e. Only 2 of the above (a. – d.) are correct f. Only 3 of the above (a. – d.) are correct g. All 4 of the above (a. – d.) are correct h. None of the above is correct
Resistivity = 17.8 Megohm-cm; TOC = 1 ppb; Bacteria = 3 cfu/L; Oxygen 4.2 ppm. The effluent of this UV unit will likely have:
a. Lower resistivity b. Lower TOC concentration c. Lower bacterial count d. Lower oxygen concentration e. Only 2 of the above (a. – d.) are correct f. Only 3 of the above (a. – d.) are correct g. All 4 of the above (a. – d.) are correct h. None of the above is correct
18. Compared to the influent, the effluent of the secondary mixed-bed ion exchange unit will likely have:
19. The purpose of the UF treatment step is to:
a. Remove any dissolved organic compounds that have made it through the treatment scheme b. Remove any dissolved silica compounds that have made it through the treatment scheme c. Remove any carbon dioxide that has made it through the treatment scheme d. Remove any boron that has made it through the treatment scheme e. Only 2 of the above (a. – d.) are correct f. Only 3 of the above (a. – d.) are correct g. All 4 of the above (a. – d.) are correct h. None of the above is correct
20. If the drinking water to the plant contains 5 mg/L of TOC, which piece of equipment removes the highest percentage of TOC?
a. First pass RO unit b. Second pass RO unit c. EDI unit d. MB IX unit e. 185 nm UV unit f. None of the above