The biological aerobic process employs microbes to eliminate inorganic and organic matter available in the wastewater. The challenge is that measuring the growth of microbes is time-consuming and requires expensive laboratory equipment and a trained professional microbiologist. Techniques used to measure the growth of microbes are classified under indirect and direct methods.

Indirect methods include metabolic activity, turbidity, and dry cell weight, while direct methods include direct microscopic count, plate count, filtration, and most probable number (Koch 2007). These methods are reliable and have been proven to produce satisfactory results.

However, in a climate-changing environment where temperatures continue to rise, application of the indirect and direct methods may be disadvantaged, since most of them rely on laboratory experiments. The current study proposes measuring the oxygen uptake rate (OUR) of microbes to monitor the performance of the biological aerobic process in a climate-changing environment...