Ag Engineering PE Review: Section V-A: Biological Processes

1. Ag Engineering PE Review: Section V-A: Biological Processes Ann D. Christy, PhD, PE Associate Professor Department of Food, Agricultural, and Biological Engineering

2. Outline • Exam Preparation Tips • Principles of Organic and Biochemistry • Aerobic and Anaerobic Processes • Ergonomics

3. Part 1: Exam preparation tips • Lecture IIIB, part 1 (Dr. Lima’s PPT materials for this PE review course) www.bae.ncsu.edu/www3/pe/2007/materials.htm • A Guide to Professional Licensure for Agricultural, Food, and Biological Systems Engineers. 2005. http://www.asabe.org • Any of the PPI reference books for PE exam (Civil, ME, Environmental, etc.) http://ppi2pass.com

4. References • Essential -- you will not pass the exam without the proper references, tabbed, and ready to go • Know your references -- the idiosyncrasies of your texts • Choose books with good indexes • For a comprehensive list of references, see: • A Guide to Professional Licensure for Agricultural, Food, and Biological Systems Engineers. • Official ref list is in the review website.

5. Other tips • Take time during the test to: • Read each question thoroughly • Check your calculations • Check your UNITS -- easy errors to make • Lindeburg, M.R. 1999. Engineering Unit Conversions. 4th ed. Professional Publications, Inc., Belmont, CA. • The more work you do, the better -- practice by doing LOTS of PROBLEMS!

6. Standards you might need for V.- A. • D384.2 Manure production and characteristics • EP403.3: Design of anaerobic lagoons for animal waste management • S318.15: Safety for agricultural field equipment • S440.3: Safety for powered lawn and garden equipment • Other standards with keyword “Safety”

7. References used for this on-line session • ASABE Standards 2006 • ASHRAE Handbook of Fundamentals 2005 • Bioprocess Engineering (Shuler and Kargi) • Bioprocess Engineering Principles (Doran) • Chemistry for Environmental Engineering (Sawyer and McCarty) • Civil Engineering Reference Manual for the PE exam (Lindeburg) • Environmental Engineering Reference Manual for the PE exam (Lindeburg) • Guide to Professional Licensure for Agricultural, Food, and Biological Systems Engineers (ASABE) • Human Factors (ASABE, 1991) • Livestock Waste Facilities Handbook (MWPS-18) • Wastewater Engineering (Metcalf and Eddy)

8. Part 2: V.A. Biological processes: Principles of Organic and Biochemistry • 5 questions out of the exam’s total 80 will cover all of the Biological Processes topics • Engineering applications, not pure chemistry • Structure of tonight’s session: • Background • Sample problems and solutions • Practice problems

9. Background • Organic chemistry is “the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of chemical compounds of carbon and hydrogen, which may contain any number of other elements, such as nitrogen, oxygen, halogens, and more rarely phosphorus or sulfur. (from http://en.wikipedia.org/)

10. Background • “ The original definition of organic chemistry came from the misperception that these compounds were always related to life processes. Those compounds that are related to life processes are dealt with in the branch of organic chemistry which is called Biochemistry.” (from http://en.wikipedia.org/)

11. Organic compounds • Characteristics • Combustible • Low MPs and BPs • Less soluble in water • Isomerism (1 formula, multiple compounds) • Slow reactions (molecular, not ionic) • High MWs • Bacterial food source or substrate • Sources: Nature, synthesis, Microbial fermentation

12. Organic compounds of biological importance • Carbohydrates • sugar, starch, cellulose • polymers of C, H, O • readily available energy source • Lipids • fats, oils, steroids • glycerol + 3 fatty acids • cell structural component & energy source

13. Organic compounds of biological importance • Proteins • most abundant organic molecules in living cells • polymers of C, H, O, plus N (also S, P, etc.) • 20+ amino acids (a.a.) • hundreds of a.a.s in particular proportion, sequence, arrangement, and shape (its 3-D shape is critical to its function)

14. Protein types / functions • Structural (muscle, collagen, glycoprotein) • Transport (hemoglobin, serum albumin) • Regulatory (hormones, insulin) • Protective (antibodies, thrombin) • Catalytic (enzymes) • Nucleic acids (DNA, RNA) • Energy-transfer nucleotides (ATP, ADP)

15. Sample question • #128, ASABE, 2005 (p. 21): A blast furnace is being considered for freezing bread dough (35% water, 9% protein, 4% fat, 51% carbohydrate, and 1% ash). Air at -20°F and 10 ft/s would move around cylindrical doughs which rest on belted conveyor. As dough moves from initial state (90°F) to frozen (-20°F ), its specific heat and thermal conductivity will… • (a) both increase, (b) cp increase & k decrease, (c) both decrease, (d) cp decrease & k increase

16. Solution (p. 48) • Consider that freezing increases ratio of ice to liquid water • Look up specific heats and thermal conductivities (Lindeburg): • Cp for water = 1 BTU/ lbm- °F • Cp for ice = 0.49 BTU/ lbm- °F • K for water = 4.271 at 90°F • K for ice = 17.531 BTU-inch / hr-sq.ft.- °F at -20°F • Answer: (d ): Cp will decrease, K will increase

17. Sample question #528, ASABE, 2005 (p. 34): Estimate maximum acceptable concentration of Heptachlor in organic river sediment given that the sediment is 12% organic, Heptachlor’s octanol partition coefficient is 25,700 L/kg, and its toxicity is 0.0038 g/L (a) 0.007 g Heptachlor / g sediment (b) 0.012 g Heptachlor / g sediment (c) 0.062 g Heptachlor / g sediment (d) 0.098g Heptachlor / g sediment

18. Solution (p. 62) • Two approaches: Follow units or find equations • Equation: SQC (g Heptachlor / g sediment ) = Foc (%) x Koc (L/kg organic carbon) x WQC (g Heptachlor / L) • Look up Koc or find 2nd equation (Sawyer and McCarty): • Koc = 0.63 (Kow) • Calculate • SQC = 0.12 x (0.63 x 25,700 x 0.001) x 0.0038 • Answer: (a ): 0.007 g Heptachlor / g sediment

19. Practice Problem: Organics • Carbon tetrachloride has a hydrolysis rate constant of 3.26 x 10-8 min-1. Assuming no other reactions occur, what is the half-life in years for this compound? • (a) 70 • (b) 60 • (c) 50 • (d) 40

20. Decomposition end products • Carbohydrates: • Aerobic: CO2 and water • Anaerobic: CO2, alcohols, organic acids • Lipids: • Aerobic: CO2 and water • Anaerobic: CO2, fatty acids, glycerol, alcohols • Proteins and other nitrogen containing compounds: • Aerobic: CO2 and water • ammonia to nitrite to nitrate • Anaerobic: CO2, methane, amino acids, organic acids • ammonia, hydrogen sulfide • Anoxic (low oxygen): nitrate to nitrite to N2 gas

21. Part 3: V.A. Biological processes:Aerobic and Anaerobic Processes Biochemical redox reactions • Electron acceptor • Aerobic: oxygen as electron acceptor • Anaerobic: other electron acceptors: • Nitrate: Denitrification (forms N2) • Organics: Acid fermentation (forms VFAs) • Iron III: Iron reduction • Sulfate: Sulfate reduction (forms H2S) • CO2: Methanogenesis • Facultative: can go either way • Electron donor (substrate, feedstock)

22. Biological transformations

23. Aerobic Growth Stoichiometry

24. Product Stoichiometry

25. Sample question • #129, ASABE, 2005: A bin of stored grain is at a moisture content of 25% (wet basis). The bin is not designed to be airtight. Over time the grain deteriorates due to the action of microorganisms until 1% of the original grain dry matter is lost. Assume deterioration can be modeled as oxidation of glucose: • Assume evolved water is retained in grain mass. The % weight change of the grain mass is most nearly: • (a) +1.5, (b) +1.1, (c ) -0.4, (d) -1.0

26. Solution (p. 48) Calculate MWs: glucose = 180, water = 18, carbon dioxide = 44, oxygen gas (O2) = 32 Focus on the 1% converted to water (6*18=108): Answer: (c ): -0.4%

27. Practice Problem: Aerobic • Acetobacter aceti are used in the production of acetic acid from ethanol following the equation: • C2H5OH + O2 --> CH3CO2H + H2O • Initial and final concentrations of ethanol are 15 g/L and 3 g/L, and 10.3 g/L of acetic acid is produced in the highly aerated system. • PART 1. What is the observed yield? • (a) 1.00 • (b) 0.90 • (c) 0.85 • (d) 0.80

28. Practice Problem: Aerobic • Acetobacter aceti are used in the production of acetic acid from ethanol following the equation: • C2H5OH + O2 --> CH3CO2H + H2O • Initial and final concentrations of ethanol are 15 g/L and 2 g/L, and 10.3 g/L of acetic acid is produced in the highly aerated system. • PART 2. What is the theoreticalyield? • (a) 1.5 • (b) 1.3 • (c) 1.1 • (d) 0.9

29. Anaerobic Growth Stoichiometry

30. Anaerobic processes and mediating organisms (from Hughes and Christy, 2003)

31. Phases of anaerobic degradation Off gas composition changes with each phase: Aerobic Anaerobic acidogensis Anaerobic methanogenesis Decelerated biodegradation

32. Waste Treatment Lagoons • Low-biomass biological reactors • Large land area • Design volume: • MWPS-18: Livestock Waste Facilities Handbook (Figure 7-1; Tables 7-1, 7-2) • Geometry: • MWPS-18: Livestock Waste Facilities Handbook (Tables 11-1 to 11-3)

33. Lagoon types ( by depth) • Aerobic (1-2 ft) • Facultative (most common, 5-8 ft) • Partial-mix aerated (6-20ft) • Anaerobic (15-30 ft)

34. Design criteria • Volumetric loading rate (lbs/ft3-day) • Anaerobic lagoons • Areal loading rate (lbs/ft2-day) • Facultative lagoons • Hydraulic retention time • all types

35. Sample question • #529, ASABE, 2005 (p.34): Financial backers of a proposed 5,000 head swine farrowing facility are considering siting the facility in one of the following states. They would like to use an anaerobic lagoon for treating the manure. From the perspective of volatile solids loading rates only,the state requiring the smallest lagoon treatment volume is: • (a) Florida • (b) Kansas • (c) North Carolina • (d) Idaho

36. Solution (p. 62) • Three possible approaches: • ASABE standard EP403.3 - Figure 2 (map of USA showing max loading rates for anaerobic lagoons) • MWPS-18: Figure 7-1 (map of USA showing climatic zones) and Table 7-1 (lagoon volume per animal for each zone) • General knowledge of temperature sensitivity of biological reactions (warmer = faster reactions) Answer: (a ): Florida

37. Practice Problem: Anaerobic • Design a two-stage anaerobic lagoon for a 1250 sow, feeder pig operation located in southern Ohio. Assume two 8-piglet litters per sow per year. Include a synthetic liner in your design which allows lagoon construction using 2:1 side slopes. Use a 20 foot liquid depth which includes 2 feet of freeboard. The best dimensions (in feet) for lagoons #1 and #2 are, respectively: • (a) 150’ x 407’, 150’ x 236’ • (b) 100’ x 408’, 100’ x 234’ • (c) 200’ x 521’, 200’ x 290’ • (d) 150’ x 500’, 100’ x 200’

38. Part 4: V.A. Biological processes: Ergonomics • Ergonomics(or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance (from http://en.wikipedia.org/)

39. Human factors elements • Equipment • Controls, information displays, dimensions, arrangement of components • Environment • Temperature, illumination, vibration, noise, air quality • Task • Duration, repetitiveness, feedback, frequency of response, accuracy and speed requirements • Personnel • Intelligence, training, experience, motivation, motor skills, sensory capability

40. Sample question: Equipment • #130, ASABE, 2005 (p. 22): A monitor is to be designed for use in the cab of a tractor. The design will be located 1 m from the operator’s head. Select the most appropriate text height (mm) for the application. • (a) 6 • (b) 8 • (c) 11 • (d) 14

41. Solution (p. 48) Equation: H = 0.0022 D + K1 + K2 Where D = 39.37 inches K1 = 0.26 (night use, dynamic movement of operator) K2 = 0.075 (importance to operation of vehicle) Solution: H = 0.422 inches = 10.7 mm Answer: (c ): 11 mm

42. Sample question: Environment • For each of the following conditions, predict whether a person might be expected to feel comfortable or not. i. RH = 40%, Tdb = 72°F, light work, clothing suited to summer wear ii. RH = 40%, Tdb = 72°F, light work, clothing suited to winter wear • (a) both are comfortable • (b) both are uncomfortable • (c) first is comfortable, second is not • (d) second is comfortable, first is not

43. Solution From ASHRAE Handbook of Fundamentals (2005) Answer is: (d) second is comfortable, first is not

44. Practice Problem: Ergonomics • For each of the following conditions, predict whether a person might be expected to feel comfortable or not. • i. Tdp = 60°F, Twb = 66°F, light work, clothing suited to summer wear • ii. Tdp = 60°F, Twb = 66°F, light work, clothing suited to winter wear • (a) both are comfortable • (b) both are uncomfortable • (c) first is comfortable, second is not • (d) second is comfortable, first is not

45. Questions? Comments? Good Luck in October!