Filtration

Question 1

Name the three components of the basis of filtration

Answer 1

• particle size
• density
• chemical properties

Question 2

name some reasons why filtration is important to your culture

Answer 2

• growth rates
• stress levels
• increase mortality rates
• loss in productivity
• reduction in profits

Question 3

Name the three types of culture systems according to how water is handled

Answer 3

• flow thru (use once, dump 100% of water)
• re use (partial re-use of water, partial water dump (30-70%)
• Recirculated (re-use 100% of water. Biological filtration)

Question 4

why is it important to maintain the aesthetics of your inflow/outflow of the facility?

Answer 4

• first impressions of the general public
• if water looks dirty, its assumed you have a dirty product
• public may be alarmed by ‘dirty’ discharge water
• government agency, media attack, etc

Question 5

name the thee types of filters according to their method of removal

Answer 5

• mechanical
• chemical
• biological

Question 6

Describe Physical filtration, and name the two types

Answer 6

• a mechanical type of filter that uses the difference in the physical properties between the waste products and water for separation.
• active
• passive

Question 7

Describe a stationary screen. Name some types.

Answer 7

a physical filter. placed in the waters path, trapping particulate matter as the water passes thru it.

• cartridge/cloth filter
• diatomaceous earth filter
• vibratory screen

Question 8

describe a diatomaceous earth filter. How is this different from other physical filters?

Answer 8

• a cloth bag is placed in a vessel and diatomaceous earth is released into the stream. As water passes thru the cloth bag, the diatomaceous earth builds up on the surface, which acts as a filter medium.
• it POLISHES the water. (0.1um)

Question 9

Name two types of rotary screen filtration systems

Answer 9

disk filters, drum filters

Question 10

what is the difference between disk and drum filters?

Answer 10

disk filters have a flat screen that rotates and traps waste particles on the surface. drum filters use a screen wrapped around a cylinder, which rotates slowly and traps particles collected on the surface of the screen, removing it by a spray bar.

Question 11

describe sedimentation pond

Answer 11

uses the natural forces of gravity to extract particles. requires a large area of land if there is a great deal of water to be treated.

Question 12

name a similar alternative to sedimentation ponds, describe.

Answer 12

sand filters. wastewater is placed in a vessel and fluid is then pressurized. the pressure within the vessel forces water thru the media leaving the particulates trapped in the sands pores.

Question 13

name two types of filters that rely on enhanced natural gravitational forces?

Answer 13

centrifugal filters

hydroclones.

Question 14

name the two general types of filters employing air

Answer 14

• induced air floatation (IAF)

- dissolved air floatation (DAF)

Question 15

name a type of IAF

Answer 15

foam fractionation. enzymes and proteins adhere to the bubbles surface and remain attached to the bubble on the surface, producing foam or scum.

Question 16

define chemical filtration

Answer 16

altering the charge associated with particles or by attracting the charged particles to a media.

Question 17

name four methods of waste removal (chem filtration)

Answer 17

• chem assisted floatation (CAF)
• coagulation and flocculation
• carbon filtration
• ion exchange

Question 18

describe the CAF method

Answer 18

Chemical Assisted Method is increasing the pH which increases the binding of waste products to air bubbles, aided with an air stone. waste rises on bubbles to the top, then skimmed off.

Question 19

why use coagulation and flocculation instead of CAF method?

Answer 19

when the waste product is very difficult to remove, very small, or has strong repulsive forces.

Question 20

what is coagulation and flocculation?

Answer 20

when specific chemicals are added to the waste steam, they increase the size of the waste product prior to removal.

Question 21

Describe carbon filtration

Answer 21

utilizes the chemical properties of activated carbon particles. the activated particles have tons of fissures, increasing the SA, and therefore increasing the number of sites for waste particles to bind against.

Question 22

what is a problem with carbon filtration?

Answer 22

there is no indication that the filters are inoperative when the binding sites have been consumed. in addition, the cost of reactivating carbon is greater thatn the purchase of a new one.