What type of microorganisms are primarily used in the biological treatment of wastewater?

In the biological treatment of wastewater, bacteria are the primary microorganisms used due to their ability to break down organic matter efficiently. They play a crucial role in the decomposition process, converting complex organic materials into simpler substances, which ultimately lead to the stabilization of the waste.

Bacteria also facilitate the removal of nutrients and pathogens from wastewater through various processes such as aerobic and anaerobic digestion. Aerobic bacteria thrive in the presence of oxygen and help in aerobic treatment processes like activated sludge systems, while anaerobic bacteria operate in environments devoid of oxygen, commonly utilized in digesters for sludge management.

The other microorganisms mentioned—fungi, algae, and protozoa—do play roles in the ecosystem and some wastewater treatment processes, but they are not the primary agents in typical biological treatment systems. For instance, fungi can decompose some organic materials, but they are slower and less efficient than bacteria. Algae are important for nutrient uptake and can aid in certain processes, but they are generally not the main organisms used in conventional wastewater treatment. Protozoa feed on bacteria and can assist in the treatment process, but they are more of a secondary component rather than the primary agents of degradation.

Thus, bacteria's efficiency and effectiveness in breaking down waste make them the