Polyphosphate-accumulating organisms

Cluster of PAOs

Polyphosphate-accumulating organisms

Polyphosphate-accumulating organisms (PAOs) are a group of microorganisms that have the ability to store and accumulate polyphosphate within their cells. These organisms play a crucial role in the biological removal of phosphorus from wastewater treatment systems.

Characteristics

PAOs are typically found in environments with low levels of oxygen, such as in the sludge of wastewater treatment plants. They are able to take up phosphorus from the surrounding environment and store it in the form of polyphosphate granules within their cells. This ability allows them to remove phosphorus from wastewater, which is important for preventing eutrophication in natural water bodies.

Mechanism of Phosphorus Removal

The mechanism by which PAOs remove phosphorus involves a process known as enhanced biological phosphorus removal (EBPR). In this process, PAOs take up phosphorus from the wastewater and store it as polyphosphate. When conditions are favorable, such as when oxygen levels are low, the PAOs release enzymes that break down the polyphosphate, releasing phosphorus back into the wastewater in a form that can be easily removed.

Importance

The ability of PAOs to remove phosphorus from wastewater is essential for maintaining the health of aquatic ecosystems. Excessive phosphorus levels can lead to algal blooms and oxygen depletion, which can have detrimental effects on aquatic life. By promoting the growth of PAOs in wastewater treatment systems, it is possible to effectively reduce phosphorus levels and mitigate the negative impacts of eutrophication.

See also

• Polyphosphate
• Phosphorus removal
• Wastewater treatment