PROJECT REPORT PRESENTATION

TOPIC:A RECIRCULATING AQUACULTURE SYSTEM

PRESENTED BY:

ANDREW O. AYUKA

F21/1711/2010

SUPERVISOR: DR. OMUTO C. THINE

INTRODUCTION• Re-circulating aquaculture systems

are indoor, tank-based systems in which fish are grown at high density under controlled

environmental conditions.

•These systems can be used where suitable land or water is limited, or where

environmental conditions are not ideal for the species being cultured.

•This type of aquaculture production system can also be practiced in marine

environments

PROBLEM STATEMENT AND PROBLEM ANALYSIS

A tremendous increase in the Kenyan population with a direct proportion in demand for protein-rich food.

The higher cost of protein-rich food in the country due to higher demand and limited supply

High pollution in ponds, rivers and lakes

High concentration of ammonia causes lethal stress to fish

OBJECTIVES

OVERALL OBJECTIVE

To design a re-circulating aquaculture system.

SPECIFIC OBJECTIVES

To apply principles of design of fish pond aerators in a re-circulating aquaculture systems

design of RAS components

Statement of scope

The scope of the project is limited to engineering design and functions of aquaculture system

The design can also be done for both marine and fresh water

Site Analysis and Inventory Site location and description is very subjective and has not been

determined yet. The project however targets urban areas where land and ground water are limited like Nairobi County and its neighbouring counties which have been studied to have the highest population in the country and readily available market for fish products.

Major issues that must be considered during the site selection process are:

location of the site

environmental sensitivity of the site

climatic factors

access to water

quality of water supply and

available options for effluent disposal.

Site Analysis……………….

Literature Review

Development of RAS started in the 1950s in Japan and was later introduced in Europe in the 1970s. Its commercial utilization was also introduced Netherlands, Denmark and Germany and Egypt in 1980s.

Aquaculture in Kenya is a new technology striving to satisfy a growing market for protein-rich food (fish) and reduce poverty in rural areas.

RAS has not yet been fully embraced compared to other countries and this has been attributed to the lack of the awareness by the citizens, lack of necessary skills and lack of sufficient or reliable fish feed just but to mention a few

Why recirculate? Conserves water Permits high stocking density culture in locations where

space and or water are limited Minimizes volume of effluent, facilitating waste recovery Allows for increased control over the culture environment,

especially indoors Improved biosecurity Environmentally sustainable

Literature review cont.………..

Theoretical framework

Design and Production

Based on the client’s specific requirements, production levels and geographic locations, a design is set up which suits perfectly. All systems are built from scratch using suitable materials, such as polyester, stainless steel, PVC, poly-propylene etc. which have a very long life span

For each stage of fish species specialised systems are needed. Some examples include:

Hatching systems

Broodstock system

Fry systems

Juvenile systems

Incubation systems

Recirculation Components

Site and components

Building

Pump House

Three phase electricity

Emergency generator

Bulk feed storage

Purging and packing facilities

System components

Biofilters

UV Disinfectants

Culture Tanks

Connecting pipes

theoretical framework cont.…..

Scientific Hatcheries Huntington Beach, California

Recirculating System Applications and its advantages

Applications of RAS Larval rearing

systems Nursery systems Nutrition and health

research systems Short-term holding

systems Ornamental and

display tanks High density grow-

out of food fish

Advantages of RAS RAS offers a variety of

benefits to the fish producers in comparison to open pond culture. These include the following method:

it maximizes production on a limited supply of water

low land requirements,

ability to control water temperature

independence from adverse weather conditions

nearly complete environmental control to maximize fish growth year-round

Challenges associated with RAS

They are a bit expensive in terms of their development and operation

They require skilled technical assistants to manage and supervise complex systems

However the disadvantages should not be a point of concern as with a careful observation the precautions, all the disadvantages can be avoided

METHODOLOGY

MATERIALS AND METHODS

materials and methods

Fine & Dissolved

Solids Removal

Solids

CaptureWaste Mgmt

Biofiltration

& Nitrification

Hydraulics

CO2 Removal

Water Quality, Loading, Culture Units, Species

Aeration & Oxygenation

System Control

Disinfection & Sterilization

SYSTEM LAYOUT

Table of field Data

RAS

componen

ts

Dimensions(

m)

Other

parameters

description

Growout

tanks

R=0.5m,H=1.2

m

Biofilter sizing Ammonia

removal rate

0.65 gm-2

Nursery

tanks

R=0.3m,H=1.2

m

average water

velocity

42 cm s-1

Hatchery

tanks

R=0.3m,H=1.2

m

culture tanks intake pipe diameter  

6 inch (15.24 cm)

 

Settling

tanks

R=0.25m.

H=0.8m

differential

height

3M

Broodstoc

k tanks

R=0.45m,H=1.

2m

Pump efficiency

of

80%,

stocking

rate

98 kgm-3    

Table: Recommended water quality requirements of recirculating systems.

Component Recommended value or range

Temperature 

optimum range for species cultured - less

than 5o F as a rapid change

Dissolved oxygen

60% or more of saturation, usually 5 ppm or more for warm water fish and greater than 2 ppm in biofilter effluent

Carbon dioxide

less than 20 ppm

pH 7.0 to 8.0

Total alkalinity

50 to 100 ppm or more as CaCO3

Total hardness 50 to 100 ppm or more as CaCO3

Un-ionized ammonia-N

less than 0.05 ppm

Nitrite-N less than 0.5 ppm

Salt 0.02 to 0.2 %

Recommended water quality requirements of recirculating systems.

CALCULATION, ANALYSIS AND DESIGNTank size, number of fish and amount of water required

Height of the tank, h= 1.2 m

Diameter of the culture tank, d= 1.0 m

Volume of the tank

Using the height of water in the tank= 1.2;

V=0.9425 m3 (volume of a single tank)

Total volume of 12 culture tanks= 11.31 m3

For the determination of the number of tilapia to be in the12 culture tanks:

Assuming a stocking rate 98 kgm-3 and the size of each tilapia fish is 150 g; the mass of fish in the culture tanks can determined as follows;

If 1 m3= 98 kg.m-3;

Then for 11.31m3= 98 kg.m-3*11.31 m3= 1108kg.

Therefore the number of tilapia fish in the culture tanks; N is;

N= 7386.67 tilapia (take as 7386 tilapia)

 

Biofilter sizing

Assuming an average ammonia production rate 10 g per 45.3592 kg per day and

Ammonia removal rate 0.65 gm-2 of biofilter;

Ammonia production rate;

NH removal can be determined as follows;

Where mass of fish= 1108kg

Therefore,

NH removal =244.27 g of fish tanks per day

The required biofilter surface area, BSA can be calculated a follows;

Taking one-inch sheet rings have a specific surface area 216.54 m2/m3, the biofilter volume; BV can be determined as follows;

Therefore, BV= 1.735m3

Results

volume of a single tank

V=0.9425 m3

Total volume of 12 culture tanks=

11.31 m3

tilapia fish in the culture tanks

7386

biofilter surface area

biofilter volume 1.735m3

Designed Drawings RAS system layout

Designed Drawings

Front view

CONCLUSION

The general objective of the study was to design a re-circulating aquaculture system. Some applications of the fish pond aerations were also incorporated in the RAS systems designs

Comparison of any fishpond and a RAS shows that RAS has very many advantages:

to maximize production on a limited supply of water

low land requirements,

ability to control water temperature quality

independence from adverse weather conditions

nearly complete environmental control to maximize fish growth year-round

Maintenance practices done in RAS include:

Monitoring temperature, pH, ammonia and oxygen levels

Flushing away mechanical filters to avoid clogging of the filters

Flushing water in tanks whenever the ammonia level is high and the pH. level is to the extreme beyond control

RECOMMENDATION Aquaculture policy

Once the aquaculture policy is put in place, there would be need to harmonize various sections of legislation to avoid overlap, contradictions and conflicts

Any public funding of RAS projects should include detailed scrutiny of plans by a multidisciplinary team of independent experts.

Aquaculture development

Support for research and pilot-scale projects should be encouraged.

Partner with large scale commercial fish farmers through production agreements in the form of out-growers such as practiced in the tea, sugarcane and some rice schemes in the country

Some existing Government facilities that are essentially used as demonstration could be upgraded into commercial farm level by a group of entrepreneurs so that they run the farms on a commercial basis on lease

Human resource (Extension)

Formation of target groups and farmer-to-farmer clusters with the ultimate goal of developing a critical mass of fish farmers able to move aquaculture to commercial level.

Organizing field days for farmers with demonstration centers for better technology transfer

Training clusters of fish farmers in aqua-business in line with the upgrading of demonstration centers for the same purpose

Investment Cost Quant

ity

Unit

Price

KSH

KSH

1 Building and Utilities (1200m2)

1 1800000

1800000

2 growout Tanks 50cm radius

12 2500 30000

3 Settling Tanks 25cm radius

8 1500 12000

4 nursery Tanks 30cm radius

8 1800 14400

4 hatchery Tanks 30cm radius

6 1500 9000

6 Brood stock Tanks 45cm radius

6 2000 12000

4 Storage Tanks10000lt

3 40000 120000

5 Pumps 1kWh 2 5000 10000

  0.75kWh 5 45000 22500

  0.5kWh 1 3500 3500

  Submersible 0.5kWh

2 2000 4000

6 Oxygenator-Quad 40

2 4000 8000

7 Sandfilter-Triton 60

6 1500 9000

8 Biofilter 10 10000 20000

9 Aerator and LHO 6 3000 18000

1

0

Pipes and valves Of various diameters

Lump sum

120000 120000

1

1

Generator -Voltmaster 15kW

1 120000`

120000

1

2

Water Quality Equipment

Lump sum

20000 20000

1

3

Office Equipment

Lump sum

300000 300000

  Total 2652400

REFERENCES

1.Buck, P. D. (2014). Land based recirculation systems. Retrieved hmarc 9, 2014, from (http://www.awi.de/de/forschung/neue_technologien/marine_aquaculture_maritime_technologies_and_iczm/research_themes/marine_aquaculture/land_based_recirculation_systems/la

2. Illora, I. M. (2008). Hydrodynamic characterization of aquaculture tanks and design criteria for improving self-cleaning properties. Castelldefels: technical university of Catalonia.

3. Inc, D. A. (2012). UV Size chart. Retrieved March 21, 2014, from http:// definitive-aquarium.com/tools/uv_size_chart.html

4. Industries, D. O. (2008). Best practice environmental management guidelines of primary industries. Victoria: Department of Primary Industries.

5. Leschen, I. A. (2011). Case study on developing financially viable Recirculation Aquaculture Systems (RAS) for tilapia production in Egypt: Technology transfer from the Netherlands. Alexandria: Egyptian Aquaculture Centre and Institute of Aquaculture, University of Stirling.

6. Libey, H. a. (2007). Fish farming in recirculating aquaculture systems (RAS). Virginia: department of fisheries and wildlife sciences, Virginia technology.

Thank you