Harmful Cyanobacterial Bloom Control with Hydrogen Peroxide: Mechanism, Affecting Factors, Development, and Prospects

Purpose of Review

Hydrogen peroxide (H₂O₂) has demonstrated significant potential in controlling cyanobacterial blooms, with its efficacy and ecological effects assessed across diverse aquatic ecosystems. This review scrutinized the death mechanism, affecting factors, impact on the aquatic ecosystem, and development and challenge of the technique; aimed to assist with the application; and provide direction for future study.

Recent Findings

Glutathione and glutathione peroxidase were pivotal in the detoxification of H₂O₂ in bloom-forming cyanobacteria, yet this system is less efficient than that in chlorophytes and diatoms, leading to selective suppression on cyanobacteria and a shift toward other phytoplankton after H₂O₂ application. Notably, colonial Microcystis was less sensitive than filamentous bloom-forming cyanobacteria, and non-toxic Microcystis was less sensitive than toxic Microcystis. Light intensity was particularly important for the effective application of H₂O₂. The presence of chlorophyta, H₂O₂-degrading bacteria, and high cyanobacterial biomass will diminish the removal efficiency. Toxic metabolites such as microcystin could be degraded in a couple of days. Consecutive H₂O₂ exposure, slowing-releasing H₂O₂ formulation, and combining with other technologies would be efficient ways to minimize non-target effects specifically on zooplankton, e.g., rotifer and cladoceran.

Summary

H₂O₂ is recognized as an environmentally friendly and promising cyanocide. It could be particularly applied in the early stage of cyanobacterial bloom on sunny days. A pre-test is crucial for the successful application across various aquatic ecosystems. Future research should focus on minimizing the impact on non-target organisms, preventing secondary blooms, and refining H₂O₂ as a sustainable bloom management tool.