An aerobic culture is growing on a mixture of organic matter, such as that found in domestic wastewater, with ammonia as the N source. How many mg of nitrogen (N), phosphorus (P), and oxygen (O2) must be provided per mg of COD removed for each of the following situations? Do not derive the stoichiometric equations. Instead, answer the questions using stoichiometric generalizations. Finally, to get complete credit you need to comment on the effect that decreasing Y has on the design and/or operation of a treatment plant.

a. Yhobs = 0.80 mg biomass COD formed/mg substrate COD removed.