Management

Question 1

Solids removal techniques (7)and their mechanisms

Answer 1

1. Settling basin - gravity
2. Tube settler - gravity
3. Swirl separator - centrifugal forces
4. Screen filtration - size
5. Granular - size
6. Foam fractioning - proteins binds to air bubbles
7. Ozonation - oxidation

Question 2

4 most important sources of waste

Answer 2

1. Fecal
2. Feed fines
3. Uneaten feed
4. Sloughed biofilm

Question 3

5 factors affecting solid production

Answer 3

1. Fraction of uneaten feed
2. Fraction of feed fines
3. Digestability
4. Feces and feed’s resistance to shearing forces
5. Time between production and removal

Question 4

3 characteristics of solids

Answer 4

1. Specific gravity
2. Size
3. Composition

Question 5

4 reasons why it’s important to remove solids

Answer 5

1. Water quality affects fish performance
2. Plugs biofilter, screens and taps
3. Reduces N-removal
4. Solids breaks down easily, degradation and dissolves.

Question 6

Why denitrification? (2 reasons)

Answer 6

To remove the accumulated NO3 from nitrification for two reasons; high NO3 levels are toxic to fish, to reduce the pollution unit of the farmer as there is prohibited to discharge water with high concentration of nitrate NO3.

Question 7

What is the Bohr(Root) effect?

Answer 7

Blodet har sämre syretransportsförmåga vid lågt pH (och vid högt CO2 – Root)

Question 8

5 orsaker för water flow

Answer 8

1. Ge fisken syre för att kunna metabolisera fodret
2. Remove dissolved metabolites
3. Transport av solids
4. Optimum flow för fiskens hälsa, muskler och respiration.
5. Maintain water temp