In biological wastewater treatment, 'yield' is defined as what?

In biological wastewater treatment, 'yield' specifically refers to the amount of biomass produced per unit of food consumed. This concept is critical in understanding the efficiency of the treatment process, as it reflects how effectively microorganisms convert organic matter (the food) into new cellular material (biomass).

The yield is a key parameter in the design and operation of biological treatment systems, as it helps in optimizing conditions for microbial growth and improving treatment performance. The higher the yield, the more biomass is produced from the same amount of organic matter, which is desirable in a treatment process as it indicates effective conversion and retention of nutrients within the system.

Other definitions listed do not capture the essence of yield in this context. The amount of food consumed focuses only on input without considering the output, while the amount of water treated pertains to overall treatment effectiveness but does not involve biological growth metrics. The amount of energy produced may relate to the process outcomes but does not define yield in biological wastewater treatment. Thus, the emphasis on biomass production from food consumption distinctly marks the correct definition of yield in this scenario.