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Flashcards in Chap9 Deck (24)
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1
Q

9.1c 5 problems associated with TSS

A
  1. Aesthetics: turbid water associated with wastewater
  2. Filterability: remove TSS to reduce the cost of cleaning the filters
  3. Disinfection: pathogens can be protected, encased in the particles
  4. pumping: SSolid damages the pumping system
  5. corrosion: the fluid flow rate is low ->form “oxygen concentration cells” under sediment
2
Q

9.2a. 5 analytical tech available for detecting TSS

A
  1. XRF (X-ray Fluorescence)
  2. XRD (X-Ray Diffraction)
  3. PSA(particle size analyzer)
  4. SDI (silt density index): old, done in field and involved in membrane and applied P
  5. Turbidity: used for drinking water
3
Q

9.3b. 6ways to improve the separation of SS from water

A

1.Increase the terminal velocity Vt:
-increase the density btw 2 media
-size of particles as large as possible
-gravitational force by centrifugation
-adjusting Temps ->change the viscosity of the continuous phase
2.

4
Q

9.4i) Surface contributes so much to the properties of colloids?

A

their surface to volume ratio is so high

5
Q

9.4ii) the surface properties that stabilizes colloids

A

surface charge

6
Q

9.5b. is the coagulation and flocculation used in sedimentation filtration, centrifugation or w cyclones

A

Sedimentation: clarification could be used prior to filtration to reduce loading.
cheaper clarification procedure used -> larger tanks built on real estate issues -> high cost of centrifuges and cyclones

7
Q

9.1 a TSS

A

particles that are removed by 0.45-micron filters

8
Q

Colloid

A

mixtures where the solute is btw 1micron and 1 nano in diameter and not homogeneous solutions

9
Q

disperse phase

A

the solute with colloidal mixtures

10
Q

disperse medium

A

the solvent

11
Q

tyndall effect

A

the scattering of light as a light beam passes thru a colloid

12
Q

turbidity

A

suspended matter the interferes with the passage of light

13
Q

9.1b 5 sources of turbidity in the natural water

A
  • collodal rock particles
  • soil flood conditions resulting large suspended
  • dometic waste
  • industrial enffluent
  • bateria growing contribute to Organic suspended matreial
14
Q

9.1b 4 sources of TSS in industrial water

A
  • water pumped from undergd
  • sludge produced from LS and ZD (zero discharge evaporation)
  • sludge produced from municipal WWT centre
  • water involved in oil & gas
15
Q

how terminal velocity depends

A
  • large diameter -> faster velocity
  • the acceleration felt
  • greater the # in density -> the faster velocity
  • as the viscosity decreases the settling will be faster
16
Q

9.5a how coagulation and flocculation served to destabilize colloid

A

Coagulation: have suspended particles that have a surface charge, keeps particles apart thereby stabilizes the colloid

17
Q

13.1 discuss the nature of material causing turbidity

A
  1. river water during a flash flood: a great amount of topsoil contribute to turbidity
  2. polluted river water: OM is food for bac to grow up and produce additional turbidity
  3. domestic WW: N,P source of food for algae which also contribute to turbidity
18
Q

13.8 turbidity of WWTP operation

A

changing the chemical dosage

19
Q

26.4 b Conditions and why 180C used as the drying temp

A

used for total dissolved solids analysis for water supplies to remove all mechanically occluded water

20
Q

7.2 stability to hydrophobic colloids in water

A

due to their size and electrical properties and it’s affected by the chemical nature of the colloid and the chemistry of the dispersion medium

21
Q

7.3 factors affect the primary charge on colloid

A

the character of the colloid
the pH
general ionic characteristics of the water

22
Q

7.4 mechanism addition of an electrolyte bring about the destabilization of colloid in water

A

the addition of counter-ions with higher charge

23
Q

7.5 mechanism of Al(III) and Fe(III)

A

form hydroxide precipitates, colloid entrapped in the precipitates

24
Q

9.4a type of particles can be detected in tyndall effect

A

colloid 1jum to 1nm