Planet Earth

2. Planet Earth Abiotic component – non-living component Atmosphere (air) Lithosphere (soil) Hydrosphere (water) Biotic component – biosphere, living component Plants Animals Microorganisms Humans

3. Cell classification Acaryotic - viruses Prokaryotic – simple structure Eukaryotic – more complex structure Taxonomic classification Conventional classification – based on observable properties Kingdom phylum class order family genus species Genetic classification - phylogeny

4. Figure 4.1 Schematic of a rod-shaped bacterial (prokaryotic) cell.

5. Figure 4.2 Schematic of a eukaryotic cell.

6. Figure 4.3 Schematic of a virus.

7. Figure 4.4 Schematics of Anabaena and Chlorella algae.

8. Figure 4.5 Three bacterial cellular forms and arrangements.

9. Figure 4.6 Examples of a Diaptomus and Daphnia. Examples of Crustaceans/microcrustaceans

10. Figure 4.7 Photograph of Dr. W. Jack Lackey holding a rockfish (up to 200 cm long and 57 kg in weight).

11. Figure 4.8 Examples of fungi.

12. Figure 4.9 Examples of a leech and flatworm. Helminths - worms

13. Figure 4.10 Examples of macrophytes.

14. Figure 4.11 Example of a protozoan.

15. Figure 4.12 Example of a rotifer.

16. Figure 4.13 Diagram of a virus.

17. Figure 4.14 Bacterial growth curve.

18. Microbial Growth Specific growth rate, μ, changes as species of organisms change and as the environmental conditions change. A French microbiologist, Monod, developed a relationship that showed that the specific growth rate is a function of the maximum specific growth rate, μmax, and the amount of limiting substrate (food):

19. If we combine the two equations above we get an equation that describes microbial growth rate: When microbial growth takes place in a flow-through reactor we have to account for microorganism loss through death and decay (endogenous decay) which is represented in the equation below:

20. The net growth rate for a reactor is then obtained by adding equations 4.3 and 4.4: Or: Cell yield is defined as the quantity of biomass produced per unit of substrate (food) used:

21. The equation that describes the rate substrate is used, the specific substrate utilization rate, U, is: We can then define the yield as: The specific substrate utilization rate, U, can also be described using a Monod-type function: If we substitute equations 4.4 and 4.7 into equation 4.5, we get:

23. Figure 4.15 Representation of a food chain.

24. Figure 4.16 Simple food chain.

25. Figure 4.17 Example of a food web. Source: http://www.epa.gov/glnpo/atlas/images/big05.gif.

27. Figure 4.18 Simplified diagram of the carbon cycle.

28. Figure 4.19 The nitrogen cycle in surface water. Source: EPA Nitrogen Control Manual (1993), p. 7.

29. Nitrification Nitrosomonas NH 4+ + 1.5 O2→ NO2- + 2 H+ + H2O Nitrobacter NO2- + 2 O2→ NO3- Overall Nitrifiers NH4+ + 2 O2→ NO3- + 2 H+ + H2O

30. Denitrification 6 NO3- + 2 CH3OH → 6 NO2- + 2 CO2 + 4 H2O 6 NO2- + 3 CH3OH → 3 N2 + 3 CO2 + 3 H2O + 6 OH- Overall 6 NO3- + 5 CH3OH → 3 N2 + 5 CO2 + 7 H2O + 6 OH-

31. Figure 4.20 The phosphorus cycle.

32. Figure 4.21 Schematic of simplified sulfur cycle.

33. Figure 4.22 DO profile for Norris Lake, September 5, 2007. Source: http://tnfish.org/WaterQualitySampling_TWRA/.

34. Figure 4.23 Temperature profile for Norris Lake, September 5, 2007. Source: http://tnfish.org/WaterQualitySampling_TWRA/.

35. Figure 4.24 Lake stratification during summer and winter.

36. Figure 4.25 Temperature and mixing profiles during turnover and stratification.

39. Dissolved Oxygen (DO) Depletion in Streams When a biodegradable organic is added to a natural water, bacteria naturally present in the water will begin to use the organic matter as a carbon/energy source. Aerobic organisms will use oxygen as the terminal electron acceptor in the process. This process is called deoxygenation. It can be modeled by the following equation: Rdeoxygenation = kD L Where: Rdeoxygenation = rate at which oxygen is removed from a stream, mg/L.d kD = deoxygenation rate coefficient (base e), d-1 L = ultimate biochemical oxygen demand (BOD), mg/L

40. At the same time deoxygenation is occurring oxygen may also be reintroduced into the system in a process called reaeration Reaeration takes place when oxygen from the atmosphere is dissolved into the water. When water is traveling quickly over rocks or through rapids oxygen is more quickly introduced into the water as opposed to a slow moving, quiet stream. The reaeration process can also be modeled by a first order process; RREAERATION = -k2 D Where: Rreaeration = rate of reaeration (rate at which oxygen is transferred into the stream) k2 = reaeration rate coefficient (base e), d-1 D = dissolved oxygen deficit, mg/L D = DOsat - DO DOsat = DO saturation concentration at stream conditions DO = actual or measured DO

42. Figure 4.26 DO versus time.

43. DO Depletion Model (Streeter-Phelps Equation)

44. If we substitute Equation 4.30 into equation 4.29 we get: Now we integrate with the boundary conditions: When t = 0, D = Do, L = L0, and When t=t, D = Dt, L = Lt

45. To use this equation we need to calculate the DO deficit at the point of dischagre, Do. First we must calculate the DO at the point of discharge: Now the DO deficit is: Sometimes we have to adjust the reaction rate constants for temperature. This can be done using the Van’t Hoff-Arrhenius equation:

46. Ө should be 1.024 for k2. For kD, Ө should be 1.145 when the temperature is 200C or less, and 1.056 when the temperature is between 20 and 300C. The maximum deficit will occur when the reaeration rate is equal to the deoxygenation rate. This point is called the critical pointand can be found be differentiating equation 4.33 and setting the result equal to zero: tc = time of travel to the critical point. Once you find tc, you can use that time in equation 4.33 to find the maximum deficit.