chap 13 Flashcards
SP. 1a. List 4 boards categories of methods used to separate DO from water
adsorption
exclusion
stripping
extraction
SP. 1b. What types of contaminants are removed using these techniques?
dissolved organics
SP.1b. ii. Distinguish between the phases and surfaces used in each of these techniques
- adsorption: liquid/solid partition
- exclusion: liquid/liquid
- stripping: liquid/gas
- extration: liquid/liquid
SP.1c which of the tech described for removing DO from water are suitable for
- non-polar molecules - Adsorption
- slightly polar organic molecules - exclusion
- large organic molecules -
- volatile organic compounds - stripping
SP.1c which of the tech described for removing DO from water are suitable for
- non-polar molecules - Adsorption
- slightly polar organic molecules - exclusion
- large organic molecules -
- volatile organic compounds - stripping
SP.1d. distinguish between the operating principles behind RO, membrane separation and pervaporation
- RO:
- membrane:
- pervaporation: permeation + evaporation
SP.1e. how are the waste streams dealt with in
GAC
Pervaporation
Stripping
GAC- once GAC is spent, it is burnt and the exhaust must be scrubbed of HCl, backwashing
Pervaporation:
stripping: Contaminants are partitioned into the air (or steam stream) therefore will be removed by GAC or Catalyst combustion using propane as a fuel
SP.1f . why would you have to protect an RO from BTX (Benzene, Toluene, Xylene)
BTX dissolves the membrane
GAC would be installed upstream of an RO unit to protect the RO membrane which can be oil soluble.
SP2a. List 3 board categories of tech used to destroy the organics in water
Chemical Oxidation
Biological Oxidation -
bio reduction - H2
SP2c. list the oxidants commonly used to destroy DO chemically
air, chromic acid, ozone, hydrogen peroxide, supper oxidation,
chlorine, ClO2
SP2c. list the oxidants commonly used to destroy DO chemically
air, chromic acid, ozone, hydrogen peroxide, supper oxidation,
chlorine, ClO2
SP2d. Chemicals sent to Swan Hills to be destroyed, what types of oxidation tech is used, what has to be done to the waste stream if heteroatoms are in the waste
Heteroatoms are atom that found in cyclical O compounds, does not include H,C. contains P,S,N,O, As
Bioreduction - reduced species such as h2S
SP2e. Advantages an disadvantages of Ozone and chlorine and recommend sutable application for each
Ozone:
ADV: low capex, source from air
DIS: high opex cuz use a lot of Electricity, toxic, strong oxidation, hard to handle, can not leave residual in water
Chlorine:
Application: disinfect water prior chlorination
ADV: leaves residual in water,easy to use, low capex
DIS: products are chlorinated substances
Application: kill bacteria and virus
SP2f. sometimes Ozone is used to remove DO from water and sometimes hydrogen peroxide is used. compare ADV, DIS of each method. Application
Hydrogen Peroxide:
ADV: not toxic as Ozone
DIS: reaction slow
Application: Toxicity reduction, BOD/COD removal
SP2g. O, OH, HOCl are oxidants used to eliminate dissolved organics from water. Give some of the chemicals used to supply these compounds
Ozone (O.)
Hydrogen peroxide (OH)
Chlorine - HOCl
SP2h. when BOIX is used to remove dissolved organics from water, do the microorganisms what supply the energy (delta G) for the reactions
supply: air (oxygen), water, carbon (food for the organisms)
the microorganism are required for the process: mircoorganism fed on the dissolved organic waste producing carbon dioxide and ater.
SOC: Synthetic organic carbon can not be dissolved by microorganism
SP2i. List the requirements for the long term maintenance of the ecosystem required in BIOX and how they are supplied
Food/BOD: maintain control w efficient BOD removal, the proper amt of food must be supplied
DO: Insufficient oxygen level inhibit BOD removal
pH/toxicants: rapid change in pH or type of waste organic inhibit the process
Time; the degree of degradation varies with time
Nutrients: bac required to trace amt of N, P for cell maintenance
Temperature: low temp -> slow rate
high temps -> kill many strain of bac
Adv and Dis of CHEMOX & BIOX
BIOX:
ADV: not dangerous like CHEMOX
DIS: reaction slow than CHEMOX (compare BOD5 and COD analyses
Different rate of bio-degradadion on # compounds
SP2k. Define F/M ratio and then give the configurations which are suitable for streams with high F/M ratio and for low F/M ratio
Food/ Microorganism ratio High F/M: -activated sludge oxidation Low F/M -aeration basin and oxidation ditches (12-48)
SP2l. which BIOX applications are suitable for a large foot print and which are suitable for a small foot print
-large foot print
SP3a four ways to remove oil and grease from water
- separation
- coalescense
- filtration
- chemical treatment
SP3b. two factors from the stokes equation are most significant for the removal of OG
size and density
SP3c. some examples of where sheering forces on OG drops in water
Sheering energy break OG to small drops
when the mixture goes thru the pumps
affects on settling time require to remove OG from water: long time
SP3d. baffles are sometimes added to skim tanks to improve separation of OG from water. what are the baffles added for, why is it that sometimes these baffles reduce separation efficiency
baffles are added -> shearing energy added to make the water droplets smaller and take more time to be separated
if designed is wrong, baffles can reduce separation efficiency
no baffles: water moves in narrow stream thru the tank
