Short calculations on the algae ponds.
(a) If the pond is initially seeded with 0.5 mg/dm3 of algae, how long will it take the algae to reach a cell density (i.e., concentration) of 200 mg/dm3? Sketch a rough plot of rg and CC over time.
(b) Suppose the algae limit the sun’s penetration significantly even before the concentration reaches 200 mg/dm3 by using u0 (1-CC/200). Assume u0 = 0.9 day–1. Qualitatively, what happens to the growth rate as the concentration of cells increases? Approximately how long would it take for the concentration to reach 200 mg/dm3? Why?
(c) An invading algae species can double twice as fast as the strain you are cultivating. Assume that it is initially at a concentration of 0.01 mg/dm3. How long until it becomes the dominant species in the pond (over 50% of the cell density)?
