Current Status and Recent Advances in Recirculating Aquaculture Systems

1
Current Status and Recent Advances in
Recirculating Aquaculture Systems

• LaDon Swann
• Illinois-Indiana Sea Grant College Program
• Purdue University and the University of Illinois
  Cooperative Extension Services

2
What Will be Discussed

• Sources of information
• Advantages and disadvantages
• Components
• Yellow perch biology and RASs
• Economics

3
Sources of Information

• Aquaculture Network Information Center (AquaNIC)
  http//aquanic.org
• Southern Regional Aquaculture Center RASs
  publications numbers 451-456.
• University demonstration projects

4
RAS Advantages

• Reduced water requirements
• Year round production
• Ability to use existing buildings
• High yields per gallon of water
• Improved feed conversion
• Reduced reproduction
• More control

5
RAS Disadvantages

• High initial investment
• Complexity
• Chronic sub-lethal effects of ammonia and carbon
  dioxide
• Lack of successes for lenders
• Inefficiencies in filtration

6
RAS Components

• Site components
• pump house
• emergency generator
• 3 phase electricity
• bulk feed storage
• oxygen supply
• building

• System components
• biological filter
• solids filter
• tanks
• aeration
• buffering systems
• heaters/chillers
• lighting

7
Site Components

• Building
• Water
• Electricity
• 3 phase preferred
• Other
• bulk feed
• oxygen tanks
• emergency generator

8
Building

• Pole barn
• enclosed or semi-enclosed
• access
• foam insulation
• moisture proof
• floor drains

9
Electricity

• 3 phase electricity
• electricity is a major cost and 3 phase will
  reduce the expense
• Emergency generator
• in event of power outage there is a 30 minute
  window to restore power to system.

Natural gas generator
10
System Components

• Primary
• Solids filter
• Biofilter
• Tanks
• Aeration
• Secondary
• Pumps
• Heaters/chillers
• Lighting
• Disinfection

11
Solids Filtration

• Sources
• Fish wastes
• Uneaten food
• Types
• Settable
• Suspended
• Fine and dissolved

Pressurized downflow sand filter
12
Solids Filtration

• Settable solids (gravity removal)
• Sediment trap
• Settling tank
• Inclined tubes
• Hydrocyclone (swirl separator)

Gravity Sump
13
Solids Removal

• Suspended Solids (non-gravity)
• Screen filtration
• Expandable granular media
• Downflow (fine sand)
• Upflow (course sand)

Suction
Screen
Screen filters
14
Solids Filtration

• Fine and dissolved solids
• Foam Fractionation
• Principle
• Particles attachto bubbles thatrise
  throughtube.

15
Biological Filtration

• Sources
• Fish metabolism
• Function
• Nitrification
• Oxidizes ammonia and nitrite to nitrate

16
Types of Bio-filters

• Submerged filters
• Simple
• Inefficient
• Trickling filters
• Simple
• Aerates

Submerged filter
17
Types of Bio-Filters

• Rotating biological contactor
• External
• Internal

Air channel
In-tank RBC airlift driven
RBC motor driven
18
Types of Bio-filters

• Fluidized Beds
• Very fine sand
• Upflow filter
• continuous backflush

Fluidized Bed(upflow)
19
Types of Bio-filters

• Bead filters
• Plastic beads
• Solids and biofilter

20
Tanks

• Criteria
• non-toxic
• durable
• Materials
• fiberglass
• concrete
• plastic
• glass
• others with liners

21
Pumps and Blowers

• Types
• impeller driven
• blowers
• Purpose
• to move water through system
• run some types of filters

Impeller driven pump
Low pressure blower
22
Aeration

• Agitation
• Agitators
• aerates
• degasses
• Blowers
• low pressure
• powers airlifts
• Ventura tubes

Bull agitator
23
Aeration

• Oxygenation
• Non-pressurized
• Downflow bubble contactor (DBC)
• Counter current diffusion column
• U-tube diffusers

24
Aeration

• Oxygenation
• Pressurized
• Pressurized spray tower
• Pressurized packed column

Pressurized packed column
25
Bicarbonate Drip

• Rational
• CO2 removal (lt20 mg/L)
• from respiration
• Buffering
• nitrification is an acidifying process
• Purpose
• Adds alkalinity to water

26
Other Components

• Lighting
• low light levels reduce stress to fish
• Heaters/chillers
• depending on species

Heater
Chillers
27
Production Rates

• Variables
• feed
• aeration
• harvest method
• continual
• batch
• ¼ to 1 lb./gallon
• Growth rates
• 0.75 - 1.0 gram/day

28
Economics 101

• Costs
• 3 fingerlings per pound 0.90
• 2 pounds of feed per pound 0.60
• Operating costs 0.50 per pound
• Sales
• 2.25 per pound over long term (5 yrs)
• Profit
• 0.25 per pound

29
Conclusions

• Building cost
• 20 of initial investment
• Production rates
• (0.33 lbs/gallon)
• Market price
• 2.25 per pound

• A typical system
• Fiberglass tanks
• Screen filter
• Bead filter
• Foam fractionation
• Bicarbonate drip
• Aeration using pure oxygen