What type of microorganisms are primarily used in biological treatment processes?

Bacteria are the primary microorganisms utilized in biological treatment processes due to their remarkable ability to break down organic matter and other pollutants in wastewater. They are essential agents in the decomposition of waste, converting harmful substances into less toxic forms through various metabolic pathways. This process is typically facilitated in aerated or anaerobic environments, where bacteria can thrive, consuming organic materials and transforming them into byproducts such as carbon dioxide, water, and biomass.

The predominance of bacteria in biological treatment systems is a result of their rapid growth rates, adaptability to different environmental conditions, and efficiency in organic matter degradation. They can be found in a variety of wastewater treatment systems, including activated sludge processes and biofilm reactors, where they are pivotal for the treatment of municipal and industrial waste.

Other microorganisms, like protozoa and fungi, do play a role in wastewater treatment, but their contributions are secondary compared to the foundational role of bacteria. Protozoa, for example, often serve as grazers on bacteria, aiding in further purification, while fungi primarily contribute to the breakdown of complex organic matter in specific types of systems. Viruses, on the other hand, do not contribute to the treatment process in a beneficial manner; they can even be detrimental by infecting and destroying bacteria