DISCLAIMER -- This is a list of questions to help you review the concepts discussed in the class. Where specific numbers aren't given, make up your own. Please do not think this is a list of questions to memorize. There will certainly be questions on the exam that are not specifically included in this list. As for exam format, see the practice exam in a separate file.

1. Look at the class exercises and homework.
2. When you see "calculation-type" questions, be sure to look at all angles of the calculation. In other words, if asked below, to calculate D given A, B, and C, be sure you can turn the problem around and calculate A, given B, C, and D. Also if asked to calculate A, check that you know what B, C, and D you need, and where you might get this information.

1. Considering aerobic and anaerobic metabolism, which one produces methane as a byproduct? Which one requires oxygen? Which one is limited to bacteria (while the other can be accomplished by many kinds of organisms)? Which one are you?
2. Given a substrate (food), calculate the theoretical oxygen demand from stoichiometry.
3. Describe how the BOD₅ test works, what it measures, and what units the results are reported in.
4. Given appropriate lab data, calculate BOD₅.
5. Correct BOD results for temperatures not equal to 20 C.
6. Given a flow with a known BOD, calculate mass of oxygen needed to satisfy the demand.
7. Calculate the oxygen required to reduce the BOD of a given volume to a specified level.
8. What constituent does BOD measure?
9. Calculate the BOD remaining in the bottle at any time.
10. Given a decay coefficient, calculate BOD_u from BOD₅.
11. Correct the decay coefficient for temperature, given appropriate information.
12. What are the important aquatic environmental effects attributable to biological metabolism of various substances?

1. What's are the hydraulic differences between complete mix reactors, plug flow reactors and batch reactors? How does concentration vary with location inside the three kinds of reactors?
2. What reactor model would you use to analyze a shallow pond? A stream? A pipeline? A blender? A filter? Groundwater flow in an aquifer (slow velocity)? Air moving through a narrow valley? A circular airshed with mountains on three sides and a constant flow of air in off the ocean? A room in your home? An irrigation ditch? A lab beaker on a mixer? An artery in your leg?

1. What is the equation for a zero order reaction? A first order reaction? A second order reaction? A saturation-type reaction (also called Monod or variable-rate)?
2. Calculate the reaction rate constant given the half-life and the reaction order.
3. Which reaction type is exponential decay?
4. Which reaction type mimics zero order at high substrate concentrations and first order at low concentrations?
5. Which reaction type is used to model biological degradation in a BOD test?
6. How does temperature affect reaction rate? Calculate the adjustment needed for a given temperature and the rate coefficient at 20 C.

1. Write out the mass balance equation in words.
2. Define "steady state".
3. Define "conservative" pollutant and give several examples.
4. Calculate hydraulic detention (or retention) time for a reactor.
5. For batch reactors and zero, first, and second order kinetics, calculate the time needed to achieve a specified concentration of a nonconservative pollutant.
6. Write and solve mass balance problems involving steady state complete mix reactors, and all types of reactions. Be sure you know how to handle multiple inflows and outflows (e.g., seepage, multiple streams, evaporation of water, and volatilization of a chemical), and multiple reactors (series and parallel).
7. Write and solve mass balance problems involving steady state plug flow reactors and zero, first, and second order kinetics.
8. Write and solve mass balance problem involving all kinds of nonsteady state reactors with conservative pollutants.
9. Why can't you write a steady state equation for a nonconservative pollutant in a batch reactor?
10. Write and solve mixing problems.
11. Calculate dilutions needed in the lab to achieve a specified concentration given the concentration of the stock solution.

1. What's the difference between infectious and noninfectious epidemiology? What are the types of disease-causing agents of concern in each?
2. Describe the transmission cycle for diseases.
3. Describe what a vector is, what its role is, and list an example or two.
4. Describe the role and activities of civil engineers in breaking the cycle of disease transmission. List an example of each of the different activities.
5. What kinds of organisms cause disease (several classes of organisms)?
6. What's a pathogen, a carcinogen, a mutagen, and a teratogen?
7. Why don't we commonly test for pathogenic organisms in water supplies?
8. What's an indicator organism? What does it indicate?
9. What group of organisms do we use as indicators? Why?
10. When you find coliform bacteria, how sure are you that pathogens are present? Explain your answer.
11. What's the difference between acute and chronic effects.
12. Define risk.
13. Describe the elements and procedure involved in risk assessment and management.
14. What is the rule-of-thumb value used as "acceptable" risk in setting health-based standards?
15. Given a concentration in water or air, calculate the lifetime average daily dose (LADD). Do this under various assumptions of exposure (e.g., work place only, lifetime assuming 30 years residence in a single location; lifetime assuming 70 years of exposure).
16. Describe the difficulty in estimating the shapes of dose-response curves. (Why don't we have as much data as we would like?)
17. Given a daily intake and cancer slope factor (CSF), calculate the lifetime risk, assuming a linear dose-response curve.
18. What is a threshold on a dose-response curve? What does it mean?
19. What are the relationships between the threshold, the NOAEL, and the Reference Dose (RfD)?
20. What kinds of substances are assumed to have thresholds and which aren't. Describe the reasoning behind the assumption that some substances don't have a threshold.
21. Given appropriate data, calculate the Hazard Index (HI) for a noncarcinogen.
22. Given appropriate data (i.e., cancer slope factor), calculate the concentration in water or air associated with a given level of risk.
23. Given the reference dose, calculate the allowable concentration in water or air.
24. Why is it useful for civil engineers to know about dose-response?

1. Describe a food chain. Name all the parts (trophic levels).
2. What "rule of thumb" value can you assume for the fraction of energy transferred from one trophic level to another?
3. Calculate the biomass in a trophic level based on energy efficiency and the biomass in other parts of the food chain.
4. Describe the difference between a food chain and a food web.
5. Describe bioaccumulation and the mechanism responsible.
6. Given that a substance bioaccumulates, and the biomass in a trophic level in a food chain, estimate the concentration of the substance elsewhere in the food chain.
7. Describe what limiting nutrients or factors are. What are they limiting?
8. Describe biostimulation. Give examples of importance to civil engineers.
9. Describe eutrophication. What's the connection between eutrophication and biostimulation? What strategies might you adopt to control cultural eutrophication?
10. What's the connection between biostimulation and oxygen depletion in water bodies?

1. Alkalinity -- Calculate the alkalinity in meq/L and mg/l as CaCO₃. Calculate the change in pH due to adding an acid or base to a natural water with a given buffer intensity. Calculate the buffer intensity given a titration curve.
2. BOD -- See the questions above.
3. Hardness -- Calculate hardness in meq/L and mg/l as CaCO₃ given lab data. Discuss what degree of hardness you would expect in various kinds of water and explain why.
4. Adsorption -- Calculate partitioning coefficient given lab data. Calculate the mass of material adsorbed given the equilibrium concentration and partitioning coefficient. Describe the relative adsorptive strengths of different materials you used in the lab. What is the main factor contributing to these differences?
5. MPN -- Describe the difference between what is measured in the MPN test and the HPC test. Which do you expect to be higher in a natural water and why? What's a presumptive test? How is it used? What does a positive presumptive test result mean?