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41 Cards in this Set
- Front
- Back
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ammonia is removed from wastewater in secondary treatment by?
a settling b nitrifying bacteria c anoxic zone d filtering |
b nitrifying bacteria
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waste water solids that will not decay or decompose are called
a organic b inorganic c total solids d suspended solids |
b inorganic
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an inorganic substance found in waste water is
a fecal matter b sugar c sand d bacteria |
c sand
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4. The BOD closest to average domestic raw sewage is:
a) 55 mg/l b) 95 mg/l c) 195 mg/l d) 295 mg/l |
d) 295 mg/l
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5. The TSS closest to average domestic raw sewage is:
a) 55 mg/l b) 95 mg/l c) 195 mg/l d) 295 mg/l |
c) 300 mg/l
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6. The average pH of domestic sewage is:
a) 3.5 – 4.5 b) 4.5 – 5.5 c) 5.5 – 6.5 d) 6.5 – 7.5 |
d) 6.5 – 7.5
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7. The pH of septic sewage is:
a) lower than that of fresh sewage b) the same as fresh sewage c) higher than that of fresh sewage d) zero |
a) lower than that of fresh sewage
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8. A material that will not pass through a glass fiber filter is called a:
a) dissolved solid b) suspended solid c) volatile solid d) liquid |
b) suspended solid
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9. An industrial waste that has low settleable solids, high BOD and a white color is:
a) canning waste b) plating waste c) paper waste d) dairy waste |
d) dairy waste
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10. A solid that can be efficiently removed by primary treatment is a:
a) dissolved solid b) suspended solid c) volatile solid d) colloidal solid |
b) suspended solid
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11. Biological waste treatment virtually stops at temperatures below:
a) 60 Fahrenheit b) 50 Fahrenheit c) 14 centigrade d) 6 centigrade |
d) 6 centigrade
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12. The main problem with excessive inflow and infiltration is:
a) it dilutes the concentration of influent b) it reduces influent temperature c) it increases pumping costs d) it reduces detention time |
d) it reduces detention time
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13. Disease causing bacteria are:
a) decomposers b) nitrifyers c) coliforms d) pathogens |
d) pathogens
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14. One reason for preliminary treatment is to:
a) remove inorganic solids b) remove organic solids c) decrease aeration d) reduce flow |
a) remove inorganic solids
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The main difference between primary and secondary treatment is:
a) primary treatment is more expensive b) primary removes dissolved solids, secondary removes suspended solids c) secondary treatment requires chemical addition d) primary relies on physical processes, secondary relies on biological processes |
d) primary relies on physical processes, secondary relies on biological processes
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16. The gas most likely to kill wastewater operators is:
a) chlorine b) methane c) carbon dioxide d) hydrogen sulfide |
d) hydrogen sulfide
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17. At 7:00 am June 1, a flow totalizer is read. At 7:00 am June 2, it is read again. The first number is subtracted from the second number. The result should be reported on the DMR for:
a) June 1, since that date had most of the flow b) June 2, since that is the end of the flow c) either day, as long as you’re consistent d) divide the flow between the two days |
a) June 1, since that date had most of the flow
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18. Disinfection is supposed to destroy:
a) all coliforms b) all bacteria c) all pathogens d) all microorganisms |
d) all microorganisms
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19. A process in which wastewater is distributed over a fixed bed of media is:
a) activated sludge b) ponds c) rotating biological contactors d) trickling filters |
d) trickling filters
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20. Digested sludge may be dewatered by a:
a) centrifuge b) tertiary filter c) comminutor d) progressive cavity |
a) centrifuge
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21. Fecal coliforms are not generally harmful. They are used to measure the efficiency of the disinfection process, and are called:
a) parasites b) amoebas c) indicator organisms d) pathogens |
c) indicator organisms
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22. To measure flow in an open channel you need a primary device (V-notch weir or flume) and a:
a) preliminary device b) depth measuring device c) stirring device d) magnetic meter |
b) depth measuring device
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23. A flow measuring device used to report plant flow to the DNR must be calibrated every:
a) six months b) year c) two years d) five years |
b) year
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24. Anaerobic wastewater would have:
a) no life b) no phosphorus c) no dissolved oxygen d) no smell |
c) no dissolved oxygen
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25. The best way to prevent excessive grease from causing problems at a WWTP is to:
a) use degreasers b) expand primary treatment c) skim it off the surface d) control it at its source |
d) control it at its source
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26. Lift stations are used to:
a) lift heavy equipment b) pump sewage uphill c) separate solids d) control pressure in collection systems |
b) pump sewage uphill
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27. Tertiary sand filters help to:
a) reduce TSS in effluent b) reduce sand in effluent c) dry sludge d) treat BOD |
a) reduce TSS in effluent
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28. Check valves are installed to:
a) keep liquid moving in one direction b) check the pressure on a system c) control the amount of flow d) relieve excessive pressure |
a) keep liquid moving in one direction
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29. In a centrifugal pump, the motor turns the shaft, which is connected to the:
a) casing b) volute c) impeller d) lantern ring |
c) impeller
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30. A good preventive maintenance program can:
a) inhibit maintenance work b) repair broken equipment c) reduce unexpected downtime d) reduce the lifespan of equipment |
c) reduce unexpected downtime
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31. When sampling final effluent for BOD compliance, use a:
a) sterile bottle b) grab sample c) composite sample d) clean sample |
c) composite sample
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32. When entering a manhole in the collection system, always:
a) breathe through a respirator b) follow confined space regulations c) work quickly d) use a ladder |
b) follow confined space regulations
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33. The two main reasons for treating wastewater are:
a) reduce odor and solids b) for drinking and swimming c) the DNR and the EPA d) to protect the environment, and prevent disease |
d) to protect the environment, and prevent disease
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34. Before municipal sewage sludge can be land applied it must:
a) meet pathogen reduction and vector attraction reduction requirements b) be dewatered c) be mixed with lime d) meet nutrient quality requirements |
a) meet pathogen reduction and vector attraction reduction requirements
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35. Metal platers must pretreat their liquid wastes before discharging to the municipal sewer. Why is that pretreatment necessary?
a) to reduce BOD b) to reduce TSS c) to reduce toxicity d) to reduce pathogens |
c) to reduce toxicity
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36. The best way to reduce the amount of toxic chemicals dumped into the municipal sewer is:
a) impose heavy fines b) randomly monitor the collection system c) send out a questionnaire d) provide a toxic chemical drop off site |
d) provide a toxic chemical drop off site
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37. Secondary treatment should remove what percentage of BOD from the wastewater?
a) 5 – 15 b) 20 – 35 c) 50 – 60 d) 80 - 95 |
d) 80 - 95
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38. Why are algae important in a non-aerated pond?
a) it provides dissolved oxygen for the microorganisms b) it provides food for the microorganisms c) it blocks the sunlight d) it absorbs most of the BOD |
a) it provides dissolved oxygen for the microorganisms
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39. If the flow increases considerably, and the automatic sampler settings are not adjusted:
a) the sample will not be preserved b) the sample container could overflow c) they will self adjust d) the sampler will fail |
c) they will self adjust
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40. Primary sludge:
a) is less odorous than secondary sludge b) is lighter than secondary sludge c) is more volatile than digested sludge d) is ready for land application |
c) is more volatile than digested sludge
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if the automatic composite sampler gets plugged and there is no BOD sample available you should
a) use a grab sample instead b) not do a BOD analysis that day c) average yesterdays and tomorrows results d) buy a new sampler |
b) not do a BOD analysis that day
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