100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Wastewater Operator Exam TN 2024 Set With complete solution | Updated 2024/25 $11.99   Add to cart

Exam (elaborations)

Wastewater Operator Exam TN 2024 Set With complete solution | Updated 2024/25

 3 views  0 purchase
  • Course
  • Wastewater Operator
  • Institution
  • Wastewater Operator

Wastewater Operator Exam TN 2024 Set With complete solution | Updated 2024/25

Preview 4 out of 112  pages

  • August 5, 2024
  • 112
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers
  • Wastewater Operator
  • Wastewater Operator
avatar-seller
STUVATE
Wastewater Operator Exam TN 2024 Set
With complete solution | Updated
2024/25
What is the purpose of wastewater treatment? - Prevention of pollution and protect public
II II II II II II II II II II II II II II II



health
II




What is inflow? - Direct discharge into the sewer from sources other than regular
II II II II II II II II II II II II II II II II



connections
II




What is infiltration? - Seepage of groundwater into the sewer system through cracks,
II II II II II II II II II II II II II II II



manholes, pipes, and connections
II II II II




How many feet apart should manholes be placed to provide access for inspections and
II II II II II II II II II II II II II II



cleaning? - 300-500
II II II II II




Manholes must be installed - At the ends of any line 8" in diameter or larger line
II II II II II II II II II II II II II II II II II II II II



Changes in grade, size of pipe or alignment II II II II II II II II



At intersections
II II



Not greater than 400ft on a 15" diameter and smaller sewers or 500ft on 18-30" sewers
II II II II II II II II II II II II II II II




Hydrogen sulfide is made in the collection system and can cause what problems? -
II II II II II II II II II II II II II II II II



Make waste more difficult to treat
II II II II II II II



Damage concrete structures II II II



Cause odor problems II II




Biological activity in long, flat sewer lines will likely cause: - Hydrogen sulfide production
II II II II II II II II II II II II II II II II II



Oxygen deficiency in sewers, manholes, or wet wells
II II II II II II II II



Metal and concrete corrosion
II II II




What is an indicator that a toxic load has entered an activated sludge plant? - Increase in
II II II II II II II II II II II II II II II II II II II



oxygen concentration in the aeration basin
II II II II II II




What two factors can influence the amount of dissolved oxygen present? - Water
II II II II II II II II II II II II II II II



temperature and organic matter
II II II II




How does water temperature affect dissolved oxygen? - Greater temperature means
II II II II II II II II II II II II II



less D.O.
II II



Lower temperature means more D.O. II II II II




How does organic matter affect dissolved oxygen? - More organic material requires
II II II II II II II II II II II II II II



more D.O.
II II

,What are problems associated with excess nutrients? - An increase in productivity of
II II II II II II II II II II II II II II II



aquatic plants thus depleting D.O. Level
II II II II II II II



Odor problems II II



Extra vegetation near surface may inhibit light
II II II II II II




II What is your best defense against infections and disease? - Good personal hygiene
II II II II II II II II II II II II II II




What may a solids build up in a receiving stream cause? - May cause oxygen depletion
II II II II II II II II II II II II II II II II II II



and be a source of odors
II II II II II II




What problems do solids cause in the system? - Fill storage areas, clog ditches and
II II II II II II II II II II II II II II II II II



channels
II II



Interfere with mechanical systems II II II II



Associated with taste/color/clarity problems in drinking water II II II II II II




What types of solids are in wastewater? - Total solids
II II II II II II II II II II II II



Dissolved solids II



Suspended solids II II



Organic solids II



Inorganic solids II



Floatable solids II




II Fresh domestic wastewater is usually what color - Grey/dishwater color
II II II II II II II II II II II




II What color is septic wastewater typically? - Black
II II II II II II II II II




II How does fresh domestic wastewater smell? - Musty early odor
II II II II II II II II II II II




In the state of TN flow measuring devices must be calibrated and maintained to ensure
II II II II II II II II II II II II II II II



_____________ of the true flow - +/- 10%
II II II II II II II II II II




What is the parshall flume best for? - Flow with solids or debris
II II II II II II II II II II II II II II II



Large flows II II



Variable flows II




II What is the usual detention time in a primary clarifier? - 1.5-2.0 hours
II II II II II II II II II II II II II II




II What does velocity drop to in a primary clarifier? - < 1fps
II II II II II II II II II II II II II




For wastewater to be considered "disinfected" what is the qualifications? - 200 CFU/100
II II II II II II II II II II II II II II II



ml for fecal colioforms
II II II II II



126cfu/100ml for E. Coli II II II




Preliminary treatment commonly consists of: - Screening
II II II II II II II II II



Shredding
Grit removal II

,Pre aeration
II




What do coarse screens remove? - Large solids, trash, wood, tree limbs, rocks, and
II II II II II II II II II II II II II II II II



other large debris
II II II




What are three coarse screens? - Bar rack
II II II II II II II II II II II



Manually cleaned bar screen II II II II



Mechanically cleaned bar screen II II II




What are three fine screens? - Wedge wire
II II II II II II II II II II II



Rotary drum screens II II II



Escalating step screen II II




II How much spacing is between bar racks? - 3-4 inches
II II II II II II II II II II II




II How much spacing is between bar screens? - ~3/8 in to 2 inches
II II II II II II II II II II II II II II




II Where are bar racks found? - In bypass channels for when flows get diverted
II II II II II II II II II II II II II II II




If manually cleaned bar screens are not attended to frequently this could cause: - Debris
II II II II II II II II II II II II II II II II II



collecting and cause head loss
II II II II II II



Flow backs up ->Organic wastes settle out-> depletes DO -> leads to septic
II II II II II II II II II II II II II



Sudden rush of septic can lead to "shock load" II II II II II II II II




The allowable head loss behind a bar screen should be ___________ - A max of 3
II II II II II II II II II II II II II II II II II II



inches
II




On a mechanically cleaned bar screen list some maintenance items: - Drive units:
II II II II II II II II II II II II II II II



adjustments must be made if cables dont wind up evenly on drums of cable machines
II II II II II II II II II II II II II II II II



Frayed or excessively worn chain must be replaced
II II II II II II II II



Bent or broken bars must be replaced
II II II II II II




If the motor on a mechanical cleaned bar screen runs but the rack doesnt operate what
II II II II II II II II II II II II II II II II



may be the problem? - Broken chain, cable or shear pin
II II II II II II II II II II II II II




What do fine screens typically consists of: - Wedge wire
II II II II II II II II II II II II II



Closely spaced bars/screening cloth II II II II



Perforated plate II




II What are the openings of fine screens - 0.06-0.25 inch
II II II II II II II II II II II




What are the three steps of maintenance to monitor with fine screens? - Visual
II II II II II II II II II II II II II II II II II



Auditory
Proper lubrication II




II What is the opening for wedge wire screens? - 0.010-0.100 in opening
II II II II II II II II II II II II II

, What wastewater is wedgewire screen not recommended for? - Wastewater that
II II II II II II II II II II II II II



contains grease
II II




How are screenings removed from internally fed rotary drum screens? - Auger/conveyor
II II II II II II II II II II II II II II



and squeezed to drain
II II II II




How are screenings removed from an externally fed rotary drum screen - Screenings
II II II II II II II II II II II II II II II



collected in the hopper
II II II II




II What are the openings on an escalating step screen? - 0.125-0.250 inch
II II II II II II II II II II II II II




What are comminutors? - Devices with cutters and screens that shred solids and return
II II II II II II II II II II II II II II II II



them to wastewater stream
II II II II




What are three disadvantages of comminutors? - Shredded rags affect operation of
II II II II II II II II II II II II II II



downstream units
II II II



Increased load on downstream units II II II II II



Head loss downstream if not checked or maintained properly
II II II II II II II II




What are four maintenance items for comminutors and barminutors? - Check for debris
II II II II II II II II II II II II II II II



in the cutting drums and bars
II II II II II II II



Sharpen and adjust the cutting blades II II II II II



Exercise inlet/outlet gates II II



Inspect travel and rotation of cutting blades
II II II II II II




If stringing parts of rags are hanging from slotted drum or U shaped bars of the
II II II II II II II II II II II II II II II II



comminutor what would that indicate? - The cutter is worn or out of adjustment
II II II II II II II II II II II II II II II II




II What is the conventional bar screen capture rate? - 6 cubic ft/ MG
II II II II II II II II II II II II II II




How do you calculate screenings removed in cubic feet of screenings per MG of flow? -
II II II II II II II II II II II II II II II II II II



Screenings removed cu ft/day
II II II II II



——————————————————
Flow MGD
II II




II What does the paint filter test measure? - Leaching effect of your screenings
II II II II II II II II II II II II II II




What benefit does grit removal have on the treatment system? - Reduce the clogging of
II II II II II II II II II II II II II II II II II



pipes and protects moving mechanical equipment/pumps from abrasion and
II II II II II II II II II



accompanying wear
II II




What does a grit channel do? - Allow grit to settle out while keeping the lighter organic
II II II II II II II II II II II II II II II II II II II



solids moving to the next treatment unit
II II II II II II II




II What is the best velocity for a grit channel? - 1ft/sec
II II II II II II II II II II II II

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller STUVATE. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $11.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

75632 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$11.99
  • (0)
  Add to cart