Coagulation as an effective method for cyanobacterial bloom control: A review

Area of Science:

• Environmental Science
• Water Quality Management
• Ecology

Background:

• Eutrophication, driven by nutrient enrichment (nitrogen, phosphorus), causes harmful cyanobacteria blooms in aquatic ecosystems.
• Cyanobacteria blooms threaten aquatic life, ecosystem integrity, and human health.
• While reducing external nutrient loads is crucial, in-lake interventions are necessary for rapid bloom mitigation.

Purpose of the Study:

• To review coagulation/flocculation as a promising in-lake intervention for managing cyanobacteria blooms.
• To elucidate the basic principles, applications, advantages, and disadvantages of various coagulation methods.
• To provide a reference for large-scale cyanobacteria bloom governance in water treatment.

Main Methods:

• Review of chemical, physical, and biological coagulation principles and applications.
• Analysis of coagulant interactions with cyanobacteria, including challenges posed by sticky secretions.
• Discussion of coagulation's role in water purification and cyanobacteria removal.

Main Results:

• Coagulation/flocculation effectively neutralizes negatively charged cyanobacteria, promoting their destabilization and precipitation.
• Various coagulants and methods have been developed to overcome challenges like sticky secretions at high cyanobacteria densities.
• Simultaneous removal of cyanobacteria and their metabolites is achievable.

Conclusions:

• Coagulation/flocculation is a vital and effective water purification technique for controlling cyanobacteria blooms.
• Understanding the principles and optimizing methods are key to successful cyanobacteria management.
• This review serves as a significant reference for implementing large-scale cyanobacteria bloom control strategies.