Climate temperature changes and excessive airflow rate effect on two key parameters: Dissolved oxygen and microbes in the biological treatment process-aerobic bioreactor

• Biomass concentration increased with an increase in temperature up to a temperature of 32.5 °C. • DO concentration decreased with an increase in temperature up to a temperature of 35 without violating the required DO concentration of 1 – 3 mg/l. • An increase in temperature showed a significant impact on biomass concentration and DO concentration. • An increase in airflow rate did not show any significant impact on biomass concentration and DO concentration. • Aerobic bioreactor unit should be maintained at a temperature and airflow rate of 32.5 °C and 5 l/mi. The biological treatment process, aerobic bioreactor is essential for biodegradation of nutrients using microbes. The survival of microbes relies on the availability of nutrients and dissolved oxygen (DO). The challenge is that oxygen gas does not dissolve easily in wastewater which motivates plant operators to apply excessive airflow rates to uphold oxygen in the aerobic bioreactor. In addition, the rising climate temperatures suppress DO, which threatens the survival of microbes, risking poor effluent discharge. Hence, the study analyzed the climate temperature changes and excessive airflow rate effect on microbes and DO simultaneously. Climate temperature changes and excessive airflow rate on microbes and DO were analyzed using linear regression, ANOVA, and coefficient of determination (R²). Findings disclosed that climate temperature changes produced R² (0.86) and negative linear regression (0.1076 mg/L) on DO while producing R² (0.59) and positive linear regression (0.168 mg/L) on microbes. Further findings disclosed that excessive airflow rates produced R² (0.84) and positive linear regression (0.0057 mg/L) on DO while producing R² (0.0003) and positive linear regression (0.001 mg/L) on microbes. Overall climate temperatures showed variations on microbes growth (P - 8.7424 × 10 9 < 0.05) and DO (P - 6.301 × 10 29 < 0.05) while excessive airflow rates showed no variations on microbes growth (P - 0.7705 > 0.05) and DO (P - 0.98512 > 0.05) . This suggests that climate temperature change will benefit microbes despite DO being suppressed while excessive airflow rates will not benefit microbes but enhance global warming due to emissions released by blowers/pumps.