senior design

1. Redesign of a Partitioned
Aquaculture System
Austin Bartley
Kayla Kernich
Emily Skibenes

2. Introduction
https://www.facebook.com/allaboutalgae/photos/a.371644646330812.1073741825.371642179664392/371645722997371/?typ
e=3&theater

3. What is a Partitioned Aquaculture System?
Developed at Clemson University in
1989, the partitioned aquaculture
system (PAS) was designed to optimize
fish production in pond systems by
increasing net oxygen production
through the management of algal
productivity
Schematic of Partitioned Aquaculture System at Clemson University
http://www.sciencedirect.com/science/article/pii/S014486099900028X#FIG1

4. Why a Partitioned Aquaculture System?
● Major advantages of pond fish culture:
○ Low capital cost of earthen ponds
○ Reliability of pond fish production
● Disadvantages of pond fish culture:
○ Need to continuously manage pond oxygen concentration
○ Need to continuously manage other fluctuating water quality variables
● These management difficulties, combined with land, water, and environmental
constraints, have driven the search for technological improvements in pond
aquaculture

5. What is a Partitioned Aquaculture System?
http://www.lsuagcenter.com/portals/communications/publications/agmag/
archive/1999/fall/potential-for-the-partitioned-aquaculture-system-in-
louisiana
The most significant difference between
conventional pond aquaculture and the PAS is
that the PAS achieves high algal yields by
maintaining uniform water velocities
The optimization of algal production allows for an
increase in fish carrying capacity.

6. PAS Utilization for Production of Algae and Carbon Capture
● Algae transform carbon dioxide into biomass
and oxygen during photosynthesis
● Algae help in mitigating the effects of global
climate change by capturing CO2 from the
earth's atmosphere
● Algal biomass is used in various industries:
○ Nutraceutical
○ Cosmetic
○ Pharmaceutical
○ Bioenergy applications
Photo by Emily Skibenes

7. PAS Utilization for Production of Algae and Carbon Capture
● Algal raceways ponds are
commonly used in the
commercial production of
algal biomass
● Advantages:
○ Simple design
○ Low capital and operating
costs
○ Easy to construct and
operate
● PAS can be operated for
algal biomass production
instead of fish farming
Conventional Algal Raceway Ponds
http://www.sciencedirect.com/science/article/pii/S096014811300342X#bib12

8. Recognition & Definition of Problem
● Original Partitioned
Aquaculture System (PAS)
unit is scheduled to be
decommissioned in the near
future
● Removal of PAS hinders the
ability to conduct class
projects and research
● New system to be relocated
near the Student Organic
Farm
Photo by Emily Skibenes

9. 2010 qPublic.net
http://qpublic5.qpublic.net/qpmap4/map_sc_pickens.php?county=sc_pickens&layers=roads+topos

10. Goals
Biological:
● Carbon sequestration by algal
growth
○ 10 g C/m2/day
● Determining required nutrient
concentrations
● Sustaining water quality
● Maximize biomass yield
Structural:
● Raceways allowing for desired
cell retention time
○ 1 - 3 days
● Raceways allowing for desired
water velocity in channel
○ 0.125 m/s
● Integrity of system
● Safety
● Aesthetics

11. Goals
Mechanical:
● Water access
● Water movement
● Algae harvesting
● Water level control
Educational:
● Use as tool for students and
visitors

12. Constraints & Considerations
● Constraints
○ Limited monetary resources for
building/design
○ Area of land limits possible
configurations and orientations
○ Water sources in the area
limited and distant from PAS
location
○ Location floods often
● Considerations
○ Safety of working/walking around the
system.
■ Fence/height of structure prevents
children and animals from falling into
system
○ Ecological impact
○ Compensate for evaporative water loss
○ Ethical

13. 3 Questions:
User: Biosystems Engineering faculty/students
How often does algae need to be harvested?
How often/how much nutrients need to be added to the system?
What maintenance will be required?
Can this system be altered to allow for fish cultivation?
Client: Ag. Department
What are the upfront costs of installation (piping, pump, concrete, etc)?
What are the operating costs?
What future research can come from this system?
Design team:
What is the most efficient way to capture the algae?
What water velocity in the channel will produce the highest yield of algae?
What cell retention time would meet our carbon productivity goal?

14. Literature Review
https://www.facebook.com/allaboutalgae/photos/a.371644646330812.1073741825.371642179664392/371645722997371/?typ
e=3&theater

15. Past Experience/Heuristics
● Creative inquiry to replace paddle wheel design
● Experience working with and around the PAS
● Creative inquiry on aquaculture at student organic farm
● Co-op experience at Harper Corporation
● Dr. Murdoch’s Hydrogeology class on wells
● Relevant Course curriculum for various parts of PAS design
○ CE 3410: Fluid Mechanics
○ BE 4100 : Biological Kinetics
○ BE 4120: Heat and Mass Transfer
○ CE 2060: Structural Mechanics

16. Governing Equations:
● Mass balance at steady state
○ (QC/V) - (QC/V) +/- r = 0
● Specific Growth Rate (Haldane light-inhibited model)
○ μL=μmaxIL/KL+IL+IL
2/Ki
● Algal Photosynthesis:
○ 106 CO2 + 16 NO3
- + HPO4
2- + 122 H2O +18H+ = C106 H152 O53 N16 P + 106 02 +
138O2

17. Governing Equations:
● Reynolds Number
○ Re = ρudh/μ
● Bernoulli’s Equation
○ h0 + P0/ρg + V0^2/2g + Δhp = h1 + P1/ρg + V1^2/2g + Δhf + Δhm
● Energy equation
○ P1​​+​1/2ρv1
2​​+ρgh1​​=P1​​+​1/2ρv​2
​2​​+ρgh2​​
● Pump Flow Rate
○ Qg/Qw = [⍴wgL/P2ln(P0/P2)]

18. Possible Options to Address Problem
Water Source:
● Hunnicutt Creek
● Seneca River
● Well water
● Municipal water from Organic Farm
● Rain barrels
Algae Capture:
● Centrifugation
● Flocculation
● Physical Separation
○ Sedimentation
○ Filtration
PAS Elevation:
● Above ground
● Below ground
● Other levels
Outflow Water Handling:
● Pump into well source
● Pump into storage tank
● Pump straight back into system
Mechanical Flow Device:
● Paddlewheel
● Air lift pump

19. Hard Data from Literature
● Cell Retention Time for Algae Growth
○ 𝜏 = 1.2 and 2.5 days
● Culture Depth
○ d = 0.3 m and 0.61 m
● Water Velocity
○ v = 0.031, 0.062, and 0.125 m/s
The partitioned aquaculture system: impact of design and environmental parameters on
algal productivity and photosynthetic oxygen production. Drapcho, C., Brune, D. (2000)
● Algal Productivity Rate
○ 5 - 10 g C/m2/d
● External Inorganic Carbon Addition
Rates
○ 0, 0.6, and 1.2 mmol/L/day

20. Data from Field Work:
● Water level in Dr. Murdoch’s well after
heavy rainfall: 1.33 m
● Using surveying equipment, elevation
difference from site to well: (1.99 m -
1.58 m): 0.41 m
● Theoretical water level at site: 0.92 m
Photo by Emily Skibenes

21. Design Methodology & Materials
https://www.facebook.com/allaboutalgae/photos/a.371644646330812.1073741825.371642179664392/371645722997371/?typ
e=3&theater

24. Analysis of Information
Length: 15.19 m
Width: 28.35 m
Depth: 0.61 m
SA: 375.37 m2
V: 228.825 m3 or 228,824.6 L
*See appendix for calculations

25. Synthesis of Design - Advantages and Disadvantages of
Culture Depth
Culture depth: 0.25 to 0.34 m
Advantages:
● Biomass concentration is higher
Disadvantages:
● Greater temperature fluctuation
○ Water Temperature
Fluctuations (Morning -> Mid
afternoon, May - September)
■ ΔT = 12.6 °F (for d = 0.30 m)
■ ΔT = 5.4 °F (for d = 0.61 m)
Culture depth: 0.34 m to 0.61 m
Advantages:
● Easier and less expensive to
mix
Design culture depth = 0.61 m

26. Water Volume Calculations
Assuming water evaporates from the surface1 at 0.5 cm/day:
Water loss due to evaporation: 1.88 m3/day or 1876.84 L/day
Assuming Clemson’s average annual precipitation2: 127.36 cm/yr:
Water gain due to rainfall: 1.31 m3/day or 1309.73 L/day
Change in water per day:
Δ = -567.11 L/day = -0.567 m3/day

27. Water Quality Results
Samples from Hunnicutt Creek,
Seneca River, and a well near the plot
of land were tested. Desired water
quality parameters were met for all 3
sources.
Therefore, we decided to use
economics and logistics as our main
criteria for choosing water source.
Image from Google Maps

28. Cost Analysis of Water Sources
Seneca River: $6,640.00
● Includes pipe installation for 280.0 m and 2 HP pump
Hunnicutt Creek: $11,320.00
● Includes pipe installation for 516.1 m and 2 HP pump
Well water: $7,015.00
● Less variability in water quality, and less disturbance of surrounding area
Municipal water: $1,200.00
● Includes pipe installation for 57.6 m

29. Drilling a Well
Total Price: $7,015.00
Item Description Price
6’’ drilled well: 30’ @ $12/ft $3600.00
6’’ PVC casing: 70’ @ $5/ft $350.00
Bentonite Grout $150.00
Well Seal $25.00
Permit $70.00
¾ HP 10gal/min Schaefer Submersible Pump $1,100.00
260 ft 1’’ Schedule 80 Pipe and 12/3 Pump Wire in Well $520.00
PC144 44 gal tank, pressure switch, gauge, and misc. fittings $700
Ditch, Pipe, and Wire to system $350
Breaker and wire from tank to electrical panel $50
Small Rock Cover $100

30. Algae & Inoculation
● Chlorella vulgaris
● Common green algae
● Matches or is close to algae used in
reference literature
● Valuable bioproducts
Chlorella vulgaris
https://botany.natur.cuni.cz/algo/database/node/110

31. Algae & Inoculation
Steps to inoculate PAS units:
1. Receive flask stock culture
2. Transfer to 500-1000 mL beakers
a. with Bold’s Basal medium
3. Transfer to 19 L bottles
a. At least 0.5 g/L cell concentration
4. Three 19 L bottles per unit
a. Allow 4 - 6 weeks for peak biomass

32. Flow Diagram
Sketch by Emily
Mass Balance Schematic of CSTR with Internal Cell Recycle

33. Mass Balance Approach for CSTR w/ Recycle
● Utilizing mass balances and
Monod kinetics
○ Determine whether system
needs external inorganic
carbon inputs to achieve
goal of 10 g C/m2/day
Mass balance and Monod kinetic equations used
in Excel

34. Mass Balance Approach for CSTR w/ Recycle
● No addition of external inorganic carbon needed for system
Cell Retention Time (Θ) (hr) 48
Hydraulic Retention Time (τ) (hr-1) 14.75
Specific Growth Rate (μ) (hr-1) 0.023
Rate of Biomass Formation (rXB) (g/m2/day) 27.99
Rate of Carbon Productivity (rS) (g/m2/day) 10.03

35. Nutrient Addition
Nutrient g/unit/week g/system/week
Nitrogen 518.00 2072.00
Phosphorus 160.00 640.00

36. Synthesis of Design: Degree of Mixing
Mixing in an open raceway may increase algal productivity by:
● Increasing the exposure of the algal cells to sunlight
● Enhance vertical mixing
● Preventing cell settling
● Prevent thermal stratification
2 options assessed to achieve design flow of 0.125 m/s: (1) air lift pump; (2)
paddlewheel

37. Air Lift Pump
Source: Effortless Aquaponics
pressure
● Estimated cost:
$2,900.00
● Testing and research
needed to determine if
desired flow for
operating conditions
can be achieved.

38. Paddlewheels
Paddlewheels are the traditional and
most commonly used method of flow
and mixing
Uniform water velocities can easily be
achieved with the use of low rpm (1- to
3-rpm) paddlewheels
Pentair Paddlewheel Assembly
(PW11-AQ)
Cost per unit: $1,112.00
Total cost for system: $4,448.00

39. Algae Separation
● 1 x 3.5 m belt
● Duck cloth or canvas
belt
● 4 rpm or 3.8 cm/s
● Harvest every 7 days
● Frame 1.1 x 1.2 x 1.5 m
Source: Iowa State University

40. Algae Separation Cost Analysis
● Motor - $300.00 each
● Rollers - $345.00 per roller, $1,035.00 per unit
● Belt - $100.00 each
● Frame - $210.00 steel angle iron
● Other - $150.00 paint, feet, and fittings
● Total - $1795.00 per unit, $7,180.00 total

41. Instrumentation
Schematic

42. Instrumentation
Campbell Scientific AquaOne plus AquaBuoy
System
● Performs automated monitoring, control, and
alarm functions in recirculating, flow-through,
and open-pond aquaculture.
● Designed to measure input from water-quality,
flow, and amp sensors, and control aerators,
pumps, alarms, and communication devices.
● Almost any sensor can be used, including
dissolved oxygen, temperature, pH, conductivity,
salinity, turbidity, ORP, ammonia, flow, and level Price: $1,495.00

43. Fencing
Simple fence estimated at:
● 4 ft. T - post, 71 units: $260.00
● Welded wire, 4 x 100 ft., 4 rolls:
$280.00
● Amethyst Falls Wisteria, 17 plants:
$255.00
● Blackberry bush, 28 plants: $205.00
● Total: $1,000.00
● Total w/ 10% labor: $1,100.00
Amethyst Falls Wisteria
Source: www.theplantingtree.com

44. Ground Cover
Ground cover to solve problem of mowing: 1 ft of gravel estimated at:
● Recycled 57 stone: ($16/ton)(1.21 ton/yd3)(128.718 yd3)(⅔) = $1661.32
● Recycled crusher run: ($10/ton)(2 ton/yd3)(128.718 yd3)(⅓) = $858.12
● Total: $2519.43
● Total w/ 20% labor & delivery: $3023.00

45. Sustainability Measures
● Recycling water from PAS
● Carbon capture by algae
● Potential for creation of
sustainable materials
● Educational aspect

46. Budget:
Total cost of implementation:
$144,186.23
Concrete: $101,470.43
Paddlewheel: $4,448.00
Well Installation: $7,015.00
Algae Capture System: $7,180.00
Instrumentation: $1,495.00
Ground Cover: $3,023.00
Fencing: $1,100.00

47. Budget - Operating Costs
Description Energy Usage (kW-hr/day)
Paddlewheel 17.88
Inflow Pumps (2 EA) 1.024
Algae Collectors 14.32
Total Energy Usage 33.22
Solar array required: 10kW system
Total System Cost: $18,454.80
Area Requirement: 600 ft2

48. Conclusions:
Water Source:
● Well water to operate PAS
Algae Capture:
● Mechanical belt system
Nutrient Addition:
● No external inorganic carbon
needed to achieve goal
● Add 2072.00 g N/week and
640.00 g P/week
PAS Elevation:
● 2 ft deep
● 2 ft above ground
Mechanical Flow Device:
● Paddlewheel to achieve 0.125 m/s
flow velocity

49. 3 Questions of the User: BE faculty/students
1. How often does algae need to be harvested?
● Approximately every 7 days
1. How often/how much nutrient needs to be added to the system?
● Weekly addition of 2072 g Nitrogen and 640 g Phosphorous
1. What maintenance will be required?
● Weekly maintenance is required to remove the algae, the water parameters are
all monitored by sensors continuously. PAS will need to be maintained at the
beginning of each May (growing season)
1. Can this system be altered to allow for fish cultivation?
● Yes, by removing the algae capturing device and adding additional fish feed, fish
can be added

50. 3 Questions of the Client: Ag. Department
1. What are the upfront costs of installation (piping, pump, concrete, etc)?
● Total overall cost: $145,690.89
1. What are the operating costs?
● Dependent on energy source used
1. What future research can come from this system?
● Adding a greenhouse for seasonal extension
● Operating the system with fish or other aquatic organisms
● Testing varying algal capturing mechanisms for max algal yield
● Determining possibilities of air lift pumps for forced flow

51. 3 Questions of the Design Team:
1. What is the most efficient way to capture the algae?
● For our system, mechanical belt system
1. What water velocity in the channel will produce the highest yield of algae?
● During the day: 0.125 m/s
1. What cell retention time would meet our carbon productivity goal?
● 48 hours

52. Timeline

53. References/Patents
1. Brune, D., et al. (2004).19 Partitioned Aquaculture Systems: Biology and Culture of Channel Catfish Developments
in Aquaculture and Fisheries Science pp. 561–584., https://doi.org/10.1016/s0167-9309(04)80021-8.
2. Caswell, W.; Norvell, K. (2016) Algal harvesting in the Partitioned Aquaculture System: Clemson University, BE
4750 Senior Design
3. Chisti Y. (2016). Large-Scale Production of Algal Biomass: Raceway Ponds: Algae Biotechnology pp 21-40.
https://doi.org/10.1007/978-3-319-12334-9_2
4. Clark, N, Dabolt, R. (1986) A General Design Equation for Air Lift Pumps Operating in Slug Flow: AiChE Journal
pp 56-64. doi: 10.1002/aic.690320107
5. Drapcho, C., Brune, D. (2000). The partitioned aquaculture system: Impact of design and environmental
parameters on algal productivity and photosynthetic oxygen production: Aquacultural Engineering. 21. 151-168.
https://doi.org/10.1016/S0144-8609(99)00028-X

54. References/Patents
6. Gross, M
7. Mandal S, Mallick N. Biodiesel Production by the Green Microalga Scenedesmus obliquus in a Recirculatory
Aquaculture System: Applied and Environmental Microbiology. 2012;78(16):5929-5934. doi:10.1128/AEM.00610-
12.
8. Swann, L. A Fish Farmer’s Guide to Understanding Water Quality: Illinois-Indiana Sea Grant Program Purdue
University
9. Turker, H., Eversole, A., Brune, D. (2003). Filtration of green algae and Cyanobacteria by Nile tilapia,
Oreochromis niloticus, in the Partitioned Aquaculture System: Aquaculture. 215. 93-101.
https://doi.org/10.1016/S0044-8486(02)00133-3.
10. Wurts, W, McNeill, S, Overhults, D. (1994). Performance and Design Characteristics of Airlift Pumps for Field
Applications: World Aquaculture: 25(4): 51-55. http://www2.ca.uky.edu/wkrec/AirliftPumps.htm

56. Appendices - Volume Calculations

57. Appendices - Structural Calculations

58. Appendices - Water Quality Test (Hunnicutt)

59. Appendices - Water Quality Test (Seneca River)

60. Appendices - Water Quality Test (Well Water)

61. Appendices - Soil Test

62. Appendices - Design Calculations

63. Appendices - Air Lift Pump Equations
● Solving for Velocity:
○ Vg= Vw * [⍴wgL/P2ln(P0/P2)] *
○ L = 0.05 m
○ P2 = 101 kPa = 101,000 kg/m*s2
○ P0 = P2 + ⍴wgh = 106,000 kg/m*s2
○ g = 9.81 m/s2
○ ⍴w = 1000 kg/m3
○ Vw = Velocity of effluent water (m/s)
○ Vg = Velocity of injected gas (m/s)

64. Appendices - Air Lift Pump Equations (Cont.)
● Modified Bernoulli’s equation:
○ ṁ0(V0
2/2g + h0) + ṁ1(V1
2/2g + h1) = ṁ2(V2
2/2g + h2) + Δhf
○ ṁ = mass flow rate (kg/s)
○ V = velocity (m/s)
○ g = 9.81 m/s2
○ h = height (m)
○ Δhf = friction loss (m)