Senior Design Final Presentation

1. Design of Preliminary
Wastewater Treatment for
Devils Backbone Brewery
Marett Richardson Reece Wilber Sydney Lynn
Advisors: Caye Drapcho, Terry Walker, Tom Owino, Natasha Bell, Tom Jones,
Jazmine Taylor

2. Introduction
Recognizing the Problem: Devils
Backbone’s side-stream wastewater
is causing a problem at local
wastewater treatment plant (WWTP).
How to Address the Problem:
Remove high levels of BOD/COD
from the side-stream.
Photo by: Sydney Lynn

3. Goals
Bioprocessing:
● Reduce BOD to 150-200 mg/L
● Utilize biogas from waste biomass to fuel boilers
Structural:
● Structurally sound Anaerobic Digester
● Housing for CSTR and pumps
Mechanical:
● Separate yeast biomass from side-stream
● Pump to treatment location
● Mix/Aerate Anaerobic Digester

4. Safety
● Acidity of COD test
● Biogas Production
Ethical
● Who are the stakeholders?
● Food contamination
● Disrupting surrounding
environment
Considerations
Ecological
● Not to cause harm to local
environment
Ultimate use:
● Reduce the BOD
● Produce value from waste

5. Sustainability
● Use yeast waste to generate
valuable product
http://biodiversitysrilanka.org/2017/03/08/issues-of-social-environmental-
sustainability/

6. Constraints
Skills
● Outsourcing Contracting
● Knowledge of Biological
Kinetics and Heat and
Mass Transfer
Budget
● Flexible (Short Return on
Investment time)
Time
● Flexible
● Quick to reduce impact
on WWTP
Space
● 12-14 acres
Logistics
● Feasible
● Economic

7. Questions
User Questions (Devils Backbone Employee):
● What are the number of work hours needed to operate?
● What technical skills needed to operate system?
● What are the potential safety concerns?
Designer Questions (Us):
● Average weekly brewhouse wastewater sent to WWTP currently?
● How do we make flow to WWTP more constant?
● What parameters are currently required for WWTP?
Client Questions (Devils Backbone Management):
● What is the initial cost?
● What is the return of investment?
● How long will it take to construct the system?

8. Hydraulic Retention Time:
Biomass Concentration:
Governing Equations - Kinetics
Specific Growth Rate:

9. Governing Equations -Defining Variables
Kinetics
● 𝜏 = retention time (hr -1)
● KS = half saturation constant (g/L)
● S = substrate utilization (g/L)
● μmax= maximum specific growth rate coefficient (hr -1)
● μ= specific growth rate coefficient (hr -1)
● b = decay constant (hr -1)
● XB= biomass concentration (mg/L)
● YB = biomass yield
● Si= initial substrate concentration (g/L)

10. Thermal Mass Balance:
Rate of Metabolic Heat
Generation (rH):
Total Heat Generation of
Microbes (Ėg):
Governing Equations - Heat Transfer
Log mean Temperature
Difference in Pipe Flow (𝛥Tlm):
Heat Loss in System from
Single Pipe (qheat exchanger):
Reynolds Number

11. Governing Equations -Defining Variables
Heat Transfer
● 𝛥Tlm =Log Mean Temperature Difference (K)
● Tmo = Temperature of Pipe Inflow (K)
● Tmi = Temperature of Pipe Inflow (K)
● T∞ = Temperature of Reactor (K)
● U = inverse unit area thermal resistance (W/m2K)
● D = diameter of pipe in heat exchanger (m)
● L = length of pipe in heat exchanger
● U = inverse unit area thermal resistance (W/m2K)
● hi and ho = Convection Coefficients (W/m2K)
● μ = dynamic viscosity (Ns/m2 or kg/ms)
● Q = flow rate (m3/s)

12. Possible Solutions
Solid Waste:
● Animal Feed
● Anaerobic Digester
Liquid Waste:
● Constructed Wetland
● Released at 4 gal/min to
WWTP
● CSTR

13. Past Experience
● Biological Kinetics
○ COD Lab
○ CSTR Design
● Bioprocessing Classes
○ Biochemistry
○ Bioprocess Engineering
● Sustainable Energy
Production
● Heat and Mass Transfer
○ Heat exchanger design
● Internships
○ Brewery and Lab Tech Intern this
summer
○ Intern at Santasalo Gears
○ Resource recovery intern

14. Background: What is COD?
Biochemical oxygen demand (BOD)
● the amount of organic carbons that bacteria can oxidize
Chemical Oxygen Demand (COD)
● total measurement of all chemicals in the water that can be oxidized
How They’re Related:
● BOD = 60% of COD
● COD is 150-330 mg/L

15. Data: Imhoff Settling Cone
Photo by: Sydney Lynn

16. Data: COD Standard Curve

17. Data: Liquid COD Concentration
Liquid
Samples
Tube
Number Absorbance
Dilution
Factor
COD
Concentration
(g/L)
COD
Concentration
(mg/L)
1:2 - 1 1 0.646 2 22.2 22200
1:2 - 2 2 0.646 2 22.2 22200
1:4 - 1 3 0.542 4 37.3 37251
1:4 - 2 4 0.540 4 37.1 37113
Average Liquid COD = 29,691 mg/L
Photo by: Sydney Lynn

18. Data: Mass COD Concentration
Mass
Samples
Tube
Number Absorbance
Dilution
Factor
COD
Concentration
(g/L)
COD
Concentration
(mg/L)
1:10 - 1 9 0.552 10 94.9 94,845
1:10 - 2 10 0.538 10 92.4 92,440
1:20 - 1 11 0.289 20 99.3 99,313
1:20 - 2 12 0.271 20 93.1 93,127
Average Mass COD =94,931 mg/L
Photoby:SydneyLynn

19. Data: Mixed Sample COD
Concentration
Mixed
Samples
Tube
Number Absorbance
Dilution
Factor
COD
Concentration
(g/L)
COD
Concentration
(mg/L)
1:10 - 1 15 0.542 10 93.13 93,127
1:10 - 2 16 0.542 10 93.13 93,127
1:20 - 1 17 0.247 20 84.88 84,880
1:20 - 2 18 0.294 20 101.03 101,031
Average Mixed COD = 93,041 mg/L
Photo by: Sydney Lynn

20. Analysis of Data
● High COD values
○ Liquid must be treated as well
● Amount of solids
○ 40% of volume is Yeast Mass
Sample Theoretical COD
(mg/L)
Average Calculated
COD (mg/L)
Liquid (Beer) 125,000-300,000 29,691
Mass (Yeast) 120,000-200,000 94,931
Mixed Side-Stream 5,000-40,000 93,041

21. Synthesis of Design: Overall View
Brewery
Primary
Settling
Tank
Side-stream
CSTR
Solid Waste
Liquid
Waste
Generated
Yeast
Mass
Treated
Liquid
Waste
WWTP
Generated
Yeast Mass
Biogas
Iron
Sponge
Clean
Biogas
Fuel for
Boilers
Anaerobic Digester
Gas Storage Tank
Secondary
Settling
Tank

22. Primary Settling Tank
Side-stream
from Brewery
150,000 L/day
Liquid Waste to
CSTR
90,000 L/day
30,000 mg/L COD
60,000 L/day
95,000 mg/L COD
Solid Waste to
Anaerobic Digester
Volume = 152,000 L
http://ecompendium.ssw
m.info/sanitation-
technologies/settler

23. CSTR
Generated Yeast
Mass Mix
Liquid Waste
Q = 90,850 L/day
XBi = 0 mg/L biomass
Si = 30,000 mg/L COD
Q = 90,850 L/day
XB = 9.4 g/L biomass
S = 31 mg/L COD
Volume =16,000 L
𝜏safe = 4.08 hr-1
https://www.alibaba.com/product-
detail/high-pressure-continous-
stirred-tank-
reactor_60615087418.html?spm=
a2700.7724857.main07.80.3088c
01ehhJT15

24. Calculating COD Reduction in CSTR
For additional calculations, see Appendix

25. Secondary Settling Tank
Liquid Waste to
WWTP
90,120 L/day Waste
Liquid
31 mg/L COD
730 L/day Biomass
31 mg/L COD
Solid Waste to
Anaerobic Digester
Generated Yeast
Mass Mix
Q = 90,850 L/day
XB = 9.4 g/L biomass
S = 31 mg/L COD
Volume = 92,000 L
http://ecompendium.ssw
m.info/sanitation-
technologies/settler

26. Anaerobic Digester
Solid Waste
from
Settling
Tanks
60,730 L/day
95,000 mg/L COD
as biomass
Biogas
Produced
1,730,000 L/day
biogas
Temperature = 35 °C
Volume = 260,000 L
𝜏 = 4.18 day
https://en.wikipedia.org/wiki/Anaerobic_digestion

27. Temperature Profile Top of the AD
Comsol

28. Temperature in Anaerobic Digestor
Initial Thermal Mass Balance:
Flow Rate of Water in Pipe Heat Exchanger (Q):
For additional
calculations, see
Appendix

29. Mixing in Anaerobic Digestor
OVIVO LM™ Mixer
Fluid speed = 15 m/min
https://www.ovivowater.com/product/municipal/municipal-wastewater/sludge-
treatment-anaerobic-digestion/digestion-mixing/ovivo-lm-mixer-linear-motion/

30. Iron Sponge
Biogas
Produced
1,730,000 L/day
biogas
Clean Biogas
1,730,000 L/day
biogas

31. Gas Storage Tanks
Clean Biogas
1,730,000 L/day
clean biogas
https://www.alibaba.com/product-detail/Double-membrane-methane-gas-tank-
gas_60611866020.html?spm=a2700.7724857.main07.9.767f998eBYGkr5&s=p

32. Alternative Design Options
Releasing Side-stream at 4 gal/min
Brewery
Primary
Settling
Tank
Side-stream
Solid Waste
Liquid
Waste
4 gal/min
WWTP
Biogas
Iron
Sponge
Clean
Biogas
Fuel for
Boilers
Anaerobic Digester
Gas Storage Tank

33. Alternative Design Options
Releasing Side-stream at 4 gal/min to WWTP
● 24,000 gallons/day side-stream
● 4.16 days to release at 4 gal/min
● Flow-rate would have to be 16.66 gal/min
https://alliancetruckandtank.com/products/storage-tanks/

34. Alternative Design Options
Brewery
Primary
Settling
Tank
Side-stream
CSTR
Solid Waste
Liquid
Waste
Generated
Yeast
Mass
Treated
Liquid
Waste
WWTP
Generated
Yeast Mass
Secondary
Settling
Tank
Compost

35. Composting Solid Waste
● 60,730 L/day solid waste
● Cheaper Option
● No biogas production
Alternative Design Options
http://weclipart.com/compost+pit+clipart

36. Synthesis of Design: Results
Biogas Produced: 1,730,000 L/day
Amount of Energy from Produced Biogas:
64 MBTU = 18,750 kW/hr per day
Amount of Energy Required to Run System:
288 kW/hr per day

37. Synthesis of Design: Results
Cost of Design:
Component Price ($)
Gas Storage Tank 865
Liquid Pumps 2,010
Air Pumps 3,600
Anaerobic Digester 250,000
CSTR 32,000
Piping 2,000
Settling Tanks 107,079
Iron Sponge 650
Total Cost $398,204

38. Economics Results
Money Saved from Biogas Production: $196.22/day
How long to get ROI:
5.5 years operating 7 days/week
7.6 years operating 5 days/week

39. Conclusion
● COD/BOD was reduced
via CSTR
● Sustainable fuel source
for boilers
https://www.showclix.com/event/devils-backbone-pa-kick-off-beer-dinner

40. Conclusion - Questions Answered
User Questions (Devils Backbone Employee):
● What are the number of work hours needed to operate?
● What technical skills needed to operate system?
● What are the potential safety concerns?
Designer Questions (Us):
● Average weekly brewhouse wastewater sent to WWTP currently?
● How do we make flow to WWTP more constant?
● What parameters are currently required for WWTP?
Client Questions (Devils Backbone Management):
● What is the initial cost?
● What is the return of investment?
● How long will it take to construct the system?

41. Timeline

42. Acknowledgments
Carolina Bauernhaus Ales
Lexington Wastewater Treatment
Facility

43. Questions?

44. References
1. John. “Brewery Wastewater BOD values”. 24 March 2015.
http://brewerywastewater.com/brewery-wastewater-bod-values/
2. Meussdoerffer, Franz G. “A Comprehensive History of Beer Brewing”. 15 Sep.
17. https://application.wiley-vch.de/books/sample/3527316744_c01.pdf
3. Oliva-Teles, Aires, and Paula Gonçalves. "Partial replacement of fishmeal by
brewers yeast (Saccaromyces cerevisae) in diets for sea bass (Dicentrarchus
labrax) juveniles." Aquaculture 202.3 (2001): 269-278.
http://www.sciencedirect.com/science/article/pii/S0044848601007773
4. Van Der Merwe, M., Britz, T.J. “Data from Anaerobic Digestion of Baker’s
Yeast Factory Effluent Using an Anaerobic Filter and a Hybrid Digester”
Biosource Technology 43 (1992): 169-174.
http://www.sciencedirect.com/science/article/pii/096085249390177D
5. Feng, Y., Wang, X., Logan, B.E. et al. “Brewery Wastewater Treatment Using
Air-Cathode Microbial Fuel Cell” Appl Microbiol Biotechnol (2008) 78: 873.
https://doi.org/10.1007/s00253-008-1360-2 .
6. Shahida Begum and A H Nazr. 2013. “Energy Efficiency of Biogas Produced
from Different Biomass Sources”
http://iopscience.iop.org/article/10.1088/1755-1315/16/1/012021/pdf

45. 7. Otter, G. E., A.R.I.C. and L. Taylor, B,Sc., F.R.I.C. “Determination of the
Sugar
Composition of wort and beer by gas liquid Chromatography.” 8 March 1967.
Courage, Barclay & Simonds Limited, Southwark Bridge, London, S.E.I)
http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1967.tb03086.x/p
df
8. Drapcho, Dr. Caye. “Biological Kinetics”. (BE 4100) Class Notes.
9. Drapcho, Dr. Caye. “Heat and Mass Transfer”.(BE 4120) Class Notes.
10. Khanal, Samir Kumar. “Biomass Yield”. Anaerobic Biotechnology for
Bioenergy Production: Principles and Applications. Nov 18, 2011.
11. Biogas Production from Brewery Wastewater. Biothane. Retrieved from
http://technomaps.veoliawatertechnologies.com/processes/lib/pdfs/3292,Article-
Jorien-final.pdf
12. Natural Gas. U.S. Energy Information Administration. Retrieved from
https://www.eia.gov/naturalgas/weekly/
13. Moser, M, R Mattocks, Dr. S Gettier, K Roos. Benefits, Costs and
Operating
Experience at Seven New Agricutural Anaerobic Digesters. Retrieved from
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.591.1823&rep=rep1
&type=pdf
References

46. Appendices - Sample Calculations
Calculating biogas production

47. Appendices - Sample Calculations
Calculating COD and BOD Concentrations:

48. Appendices - CSTR Calculations
Hydraulic Retention Time (𝜏):

49. Appendices - CSTR Calculations
New Substrate Utilization with 𝜏safe:
Also know as, COD output for CSTR

50. Appendices - CSTR Calculations
Biomass Concentration in CSTR:
Biomass Produced in CSTR to be sent to AD:

51. Appendices - Anaerobic Digester Calculations
Specific Growth Rate of Heterotrophic Bacteria on Yeast
Mass (𝜇):
Metabolic Heat Yield [1/YH]:

52. Appendices - Anaerobic Digester Calculations
Hydraulic Retention Time (𝜏):
Biomass Concentration (XB):
Source: Biological Kinetics (BE 4100) Class
Notes. Lecture X Page X. Caye Drapcho.

53. Appendices - Anaerobic Digester Calculations
Rate of Heat Generation (rH):
System Volume (V):
Total Heat Generation in System (Ėg):

54. Appendices - Anaerobic Digester Calculations
Sum of Resistances for Heat loss (RT):
Heat Loss in System to Conduction and Convection (qloss):
Where layer 1 is the enamel
coating in the digester and layer 2
is the concrete used for the
structure.
qcond was lost only from one side
of the digester, the top, because
all other sides were perfectly
insulated with the Pamunkey soil.

55. Appendices - Anaerobic Digester Calculations
Initial Thermal Heat Balance:
● 90°C is too hot for this anaerobic digestion
● A cooling system was installed to cool system for optimum digestion
temperature

56. Appendices - Anaerobic Digester Calculations
Thermal Heat Balance to bring down to 35°C (308 K):
Heat loss required by cooling system (qheat exchanger):

57. Appendices - Anaerobic Digester Calculations
Set following values to solve for Log Mean Temperature
Difference (𝛥Tlm):
● (T∞) = 35°C = 308 K
● (Tmo) = 34°C = 307 K
● (Tmi) = 7°C = 280 K

58. Appendices - Anaerobic Digester Calculations
Solve for inverse unit area thermal resistance (U):
Convection Coefficient (hi):
The conduction (𝛥x/k) is assumed to
be 0 because it is a thin metal wall.

59. Appendices - Anaerobic Digester Calculations
Nusselt’s Number (Nu):
Reynolds Number for Turbulent Flow (ReD):

60. Appendices - Anaerobic Digester Calculations
Flow Rate of Water in Pipe Heat Exchanger (Q):