ENCE412 test 1

  1. Residential water use makes up __ % of the total water demand.
  2. Industrial water use makes up __% of the total water use.
  3. Commercial/Businesses make up __ % of the total water use.
  4. Public water use makes up __% of the water demand.
  5. Leaks account for __% of the total municipal water use.
  6. What are the names of the two drinking water plants?
    • Patuxent
    • Potomac
  7. What are 6 residential uses of water?
    • Cooking
    • Cleaning
    • Showers
    • Toilets
    • Laundry
    • Drinking
  8. How to calculate peak daily demand?
    1.8 * Average Daily Demand.
  9. Storage Equation:
    S = V - 1.5*(avg daily)
  10. What is the combined draft of water demand?
    Max Daily + Fire flow
  11. What are examples for pathogens? (3)
    bacteria, microorganisms, protozoa
  12. Safe Drinking Water Act (SDWA)
    Under SDWA, EPA sets standards for drinking water quality and oversees the states, localities, and water suppliers who implement those standards.
  13. Summary of the Clean Water Act
    The Clean Water Act (CWA) establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters.
  14. What is coagulation?
    the destabilization of particles/solids/colloids in a liquid so that they can agglomerate together to produce a larger particle.  Most coagulants that can be added are iron or aluminium salts that react with alkalinity to form metal hydroxides which initiates the coagulation process.
  15. What is the drinking water turbidity standard?
    <1 NTU
  16. What particles are removed during the coagulation process?
    • soil/sediment
    • microbes
    • metals - Cu, Al, Ca (precipitate)
    • organic particulates
    • oil droplets
  17. What is flocculation?
    The physical operation of bringing together destabilized particles (slow mix). `
  18. What are the two most common coagulants?
    Al, Fe
  19. What is the jar test?
    • Add raw water, add coagulant at 6 different doses, mix rapidly (2 mins), mix slowly (15 mins) settle 30 mins, measure turbidity
    • -find correct coagulant dose
  20. Besides the jar test, what is another way to find correct coagulant dose?
    Streaming Current Detector (SCD)
  21. How to calculate %removal?
    % removal = h/H or vp/vc
  22. For vp >vc, there is ___% removal.
  23. What does the turbidity v time graph look like for a sand filter?
    Image Upload 1
  24. What does the headloss v time graph look like for sand filter?
    Image Upload 2
  25. Disinfection is more effective in lower or higher pH? Why?
    Lower. HOCL is a strong disinfectant and is dominant when pH is low.
  26. Compared to free chlorine, how is performed chloramine in terms of disinfection?
    • weaker disinfectant
    • low demand
    • stable residual
    • no DBP's
Card Set
ENCE412 test 1
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