Laboratory experiments were carried out at the Tshwane University of Technology, Faculty of Engineering and the Built Environment, Department of Civil Engineering to determine the optimum operating temperature and airflow rate that improves AE. The airflow rates used were 5 L/min, 10 L/min, 15 L/min, 20 L/min, 25 L/min, and 30 L/min. The airflow rate range was chosen based on the fact that low airflow rate produces low OTR/K_La compared with high airflow rates. The low OTR/K_La will result in a low AE, whereas high OTR/K_La will result in high AE in the biological treatment process. The temperatures used were 15 °C, 17.5 °C, 20 °C, 22.5 °C, 25 °C, 27.5 °C, 30 °C, 32.5, and 35 °C. The temperature range was chosen based on the fact that low temperature result in high viscosity compared with high temperature. The low temperature will result in low AE, whereas high temperature will increase the AE in the biological treatment process. The biological treatment process comprised of the following components: aeration tank, dissolved oxygen (DO) meter and probe, thermostat, air pump, airflow meter, air stone disc bubble diffuser, and a digital wattmeter. The components and the schematic diagram of the biological treatment process are detailed in Table 1 and Figure 1, respectively.