In aerobic treatment processes such as activated sludge systems, the predominant microorganisms are aerobic bacteria. These bacteria thrive in environments where oxygen is present, which is essential for their metabolic processes. In activated sludge systems, air is introduced into the wastewater to maintain a sufficient oxygen level, allowing these bacteria to efficiently break down organic matter and pollutants. This process not only helps in the reduction of biochemical oxygen demand (BOD) but also supports the stabilization of waste, making it less harmful before it is discharged or further treated.
The presence of aerobic bacteria is critical because they help to convert organic materials into carbon dioxide and biomass while utilizing oxygen in the process. This conversion is a fundamental aspect of wastewater treatment, promoting the overall efficiency of the treatment system. Other types of microorganisms such as pathogenic bacteria, helminths, and viruses may be present in wastewater but are not the primary organisms involved in the aerobic treatment processes like activated sludge systems.