UNIVERSITY OF NAIROBI

DEPARTMENT OF ENVIRONMENTAL AND BIOSYSTEMS ENGINEERING

FEB 540: ENGINEERING PROJECT ORAL EXAMINATION

2014/2015 ACADEMIC YEAR

PROJECT TITLE: DESIGN OF AN AQUAPONIC SYSTEM

BY: WAMBUA LYDIA WAYUA

REG NO. F21/1731/2012

SUPERVISOR: MR. S.C. ONDIEKI

8TH May 2015

INTRODUCTION: DID YOU KNOW…?

1. Fish water is loaded with nutrients?

2. Crops can grow to their maximum potential

using fish water as they would in well fertilized

soil?

3. Crops can grow without soil?

GROWING WITHOUT SOIL (HYDROPONICS)

FISH WATER: INTENSIVE FISH FARMING

DEFINITION: AQUAPONIC SYSTEM

Aquaponics is the marriage of intensive modern fish farming in tanks to intensive modern hydroponic farming.

Hydroponic farming: “Hydro” –water, “Ponos”- working.

It is the art of growing crops in sand, gravel or liquid with added nutrients without soil.

Main crops grown in hydroponics: local vegetables, tomatoes, strawberries, lettuce, cucumber, peppers as well as ornamental crops such as herbs, roses and foliage plants.

Main fish type kept: tilapia, cat fish, Nile perch e.t.c

LITERATURE REVIEW: PIONEERS IN

AQUAPONICS

The pioneer of aquaponic system was in USA, at the

University of Virgin Islands.

The system was developed in the 1970s and has been

operational commercially since then.

LITERATURE REVIEW CONT…

Interest is expanding in sustainable agriculture and producing food closer to urban centers, stimulating involvement from a small but growing aquaponics industry.

This technology is slowly being adopted in Kenya .

Hydroponics, in Kenya :Mr. Chege Peter from Zambezi area in Kikuyu and the nutrient solution is named ‘hydropeter’.

An aquaponic farm has been operational in Kinangop by Mr. Daniel Kimani

LITERATURE REVIEW: COMPONENTS OF THE

SYSTEM

DID YOU KNOW…?

1. Aquaponics can grow 90% more food on 90%

less space?

PROBLEM STATEMENT

Problem statement

Addresses two major issues;

(1) The issue of limited land

(2) Low yields

Hypothesis

An aquaponic system can grow 90% more food on 90%

less land.

OVERALL OBJECTIVE

To design a system that integrates crop and fish farming

for a potential farmer in Kamulu area, Nairobi.

SPECIFIC OBJECTIVES

1. Evaluate and select the most suitable design alternative

2. Design of:

a) A strawberry hydroponic system

b) fish tanks and a sump.

c) Mechanical filtration devices

d) Biofilter

d) A water recirculating system: pumps, piping, and fittings

GENERATION OF CONCEPT DESIGN

FUNCTIONAL DECOMPOSITION METHOD

GENERATION OF ALTERNATIVE DESIGNS

HYDROPONIC ALTERNATIVES

HYDROPONIC ALTERNATIVES

EVALUATION & SELECTION OF DESIGN

Decision matrix was used for evaluation

MOST SUITABLE SELECTION

Selected components are:

Fish tank………………………...circular fish tank

Settable solids removal…………settling basin

Suspended solids removal………filter tank

Hydroponic system…………......vertical tower configuration

Pump………………………........centrifugal type

PRODUCT DESIGN: DESIGN STEPS

1. Design of a vertical strawberry farming system Farm dimensions

The farm dimensions were measured with a tape measure and the elevation profile obtained using a GPS and Google earth.

Number of towers (Zipgrow, 2014)

Number of crops per tower (Zipgrow, 2014)

.

DESIGN CONT…

2. Calculation of the fish tanks volume

fish rearing area ratio 1 ft3 of fish rearing to 2 ft3 of

media, (Rakocy, Masser and Losordo, 2006)

critical standing crop, a value of 0.5 pounds per

gallon recommended fish density

DESIGN CONT…

3. Calculation of the flow rate

The system flow rate was calculated using the

empirical formula:

DESIGN CONT…

4. Design of the inlet and outlet water structures for the fish tanks.

DESIGN CONT…

5. Design of the settling basins.

DESIGN CONT…SEDIMENTATION BASIN

DESIGN CONT…

6. Design of the piping network.

fluid flow continuity equation Q = AV

From which,

A=Q/V

A=∏r2; r = ; d=2r, where d is the pipe diameter.

The head loss in the pipes is determined as:

hf =

DESIGN CONT…

Selection of a suitable pump for the system

Calculation of system head:

pump power requirement will be obtained using the

equation:

SYSTEM LAYOUT

RESULTS

CONCLUSION: ESTIMATED ANNUAL PRODUCTION

FROM THE DESIGNED SYSTEM.

RECOMMENDATIONS

Solar power harnessing

Rain water harvesting

REFERENCES

LOSORDO.T.M, MASSER.M.P and RAKOCY.J, (1998),

Recirculating Aquaculture Tank Production System: An

overview of critical considerations, SRAC Publication No. 451,

New York

MALONE .R. (2013), Recirculating Aquaculture Tank

Production System: A review of current design practice, Southern

Regional Aquaculture Centre (SRAC) Publication No. 453

MASSER .M.P, RAKOCY.J and LOSORDO .T.M, (1999),

Recirculating Aquaculture Tank Production System:

Management of Recirculating Systems, SRAC Publication No. 452,

New York

THE END

THANK YOU

EXTRA SLIDES

COST-BENEFIT ANALYSIS

SITE ANALYSIS

Tilapia thrive in the temperature range of 21.11° C to

29.44° C while the recommended temperature for

strawberries is 15-30°C. Thus these two fall exactly

within the temperature range in Kamulu.

electricity supply to the area

Strawberries require maximum sunlight exposure

BILL OF QUANTITIES