ENCE411 Test 1

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ENCE411 Test 1
2012-10-11 10:37:12
environmental engineering ence411

exam 1 flashcards
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  1. In WW TMT, what are the Primary Plant mincronutrients?
    • Nitrogen
    • Phsosphorous
    • Potassium
  2. Purpose of Primary Treatment 
    Removal of Solids
  3. What is the purpose of Seconday Treatment?
    Reduces oxygen demand in effluent water
  4. How do you remove Phosphorous from wastewater? What is the purpose of removing this phosphorous?
    • Adding Ferric Chloride
    • Purpose is to limit algae growth in effluent water 
    • forms ---> FePO4
  5. What is nitrification?
    Aerobic Biological treatment that reduces ammonia (NH3) and adjusts water to neutral pH by adding O2
  6. What is measured in the final effluent to meet water quality standards?
    • -Residual Chlorine
    • -E Coli (for pathogen destruction)
    • -Metals (comes from FeCl) 
  7. What are 3 sources of systematic errors?
    • 1- Instrument Error (calibration)
    • 2- Method Error (ex slow or incomlete reactions)
    • 3 - Personal error (insensitivity to color changes, estimate scale readings)
  8. What is a hygroscopic material?
    Reagents that readily pick up water.
  9. What is a deliquescient material?
    Materials that dissolve with water.
  10. Why is determining dissolved solids important for the environment?
    • -Waters with high dissolved solids may cause constipation and taste nastay
    • - Inversely impact irrigated crops and grasses
  11. Why is it important to determine suspended solids?
    • SS can float and cause scum layers
    • or SS can sink and cause sediment buildup
    • it is aesthetically unacceptable
  12. TS Total Solids = ? + ?
    Organic Solids (volatile) + inorganic solids (fixed or inert solids)  = TDS + SS
  13. How would you find the amount of Total Dissolved Solids (TDS)?
    • 1) Filter well-mixed sample through glass fiber filter disk;
    • 2) obtain filtrate,
    • 3) evaporating the filtrate to dryness in a weighed dish and
    • 4) drying it to a constant weight at 180oC. 
  14. How to find Total Suspended Solids (TSS)
    • 1) Weigh clean glass-fiber filter;
    • 2) vacuum filter a well mixed sample;
    • 3) dry filter with residue at 103-105 oC;
    • 4) cool;
    • 5) and weigh filter paper again;
    • 6) repeat until constant weight.
  15. Why is it useful to determine the whether a solid is fixed or volatile? 
    useful in the evaluation of wastewater treatment plant operation because it gives a rough approximation of the amount of organic matter present in the solid fraction of wastewater, activated sludge, and industrial wastes.
  16. How to determine amount of total Fixed solids vs total Volatile Solids
    • Weigh clean porcelain dish;
    • pour a given volume of a well-mixed sample;
    • evaporate and dry (103-105 oC);
    • ignite at 550 oC; cool;
    • weigh dish again,
    • repeat until constant weight.
  17. Applications of SS 
    • -determine the efficiency of treatment units
    • -regulated for stream pollution control
    • -TSS and VSS determinations are used for evaluating the strength of domestic and industrial wastes.
  18. Defiintion of Turbidity: 
    Insoluble particles of soil, organics, microorganisms, and other materials (suspended and colloidal) that impede the passage of light through water by scattering and absorbing the rays.
  19. What are some issues with measuring turbidity?
    -disparity of particles (organic vs inorganic) etc make it hard to establish hard and fast rules for turbidity
  20. As of January 1, 2002, turbidity may never exceed ___ NTU, and must not exceed ___ NTU in 95% ofdaily samples in any month.”
    1, .3
  21. What are some health-related risks associated with turbidity?
    -For chlorination to be effective, there must be contact with the chlorine and the target organisms, which can be affected by turbidity/particulate matter
  22. Name some applications for turbidity data
    • -Turbidity helps determine treatment required for raw water (determines coagulation/flocculation)
    • -used to check for filter effectiveness
    • -helps gauge the amount of chemicals (feeders) needed 
  23. what are some characteristics of activated sludge bugs?
    • 1) aerobic 
    • 2) uses organic compounds for both carbon and electrons
    • 3) nutritionally versatile 
    • 4) good floc formers
  24. What are some problems with activated sludge?
    • -Rises after a short settling period due to dentrification (N2 gas)
    • -causes operational problems and non-comliance with effluent discharge
  25. Function of protozoa
    • -Removal of coliform and pathogens from fecal matter
    • -contribute to flocculation
    • -break up large floc masses through motility
  26. What do the bacteria do to the activated sludge?
    the bacteria which are chowing down on all that tasty organic matter and stabilizing it by turning it into more bacteria…which can form floc and be removed from the system through settling.
  27. What is the purpose of gram staining in WW ttmt?
    • -Detection of protozoa amd filamentous organisms; indicateds well-operated sludge system
    • -Toxicity assesment: if protozoans shift from stalked ciliates to flagellates and free-swimming ciliates, indicates breakup of floc
  28. What is the issue with filamentous microorganisms in activated sludge?
    The filamentous microorganisms causes filamentous bulking that consists of slow settling and poor compaction
    • a) Aerobic
    • b) Anaerobic
    • c) Facultative
    • d) Microaerobic
    • e) aerotolerant
  29. What is a facultative anaerobe?
    A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation. In contrast, obligate anaerobes die in the presence of oxygen.
  30. Classification of microbes according to increasing temperature? (4)
    • Psycrophile
    • Mesophile
    • Thermophile
    • Hyperthermophile
  31. Mineralization
    measure amount of CO2 produced when organic carbon in thesample is oxidized by a strong oxidizer and comparing to a standard.
  32. Chemical Oxygen Demand (COD)
    the measured amount of oxygen needed tochemically oxidize the organics present to CO2 and water.
  33. Biological Oxygen Demand (BOD)
    Measurement of the rate at which microbes degrading organic matteruse oxygen
  34. Theoretical Oxygen demand (ThOD)
    calculated theoretical O2 demand forknow molecular structures (as O2). (use stoichiometry to find oxygen content)
  35. What is the importance of BOD? (5)
    • 1-relative measure of biologically degradable organicmatter in the system
    • 2-Important indicator of organic pollution (streams)
    • 3-It is a common discharge permit criterion
    • 4-An important design load parameter for aerobic biological treatment facilities.
    • 5-May be a basis of sewer rental charges for industries discharging to city treatmentworks.