A critical review of ionizing radiation technologies for the remediation of waters containing Microcystin-LR and M. aeruginosa.

Harmful algal and cyanobacterial blooms pose threats to human and ecological health due to their release of hazardous toxins. Microcystin-LR (MC-LR), a potent hepatotoxin, is the most prevalent cyanotoxin found in freshwater blooms. Although produced by many species of cyanobacteria, Microcystis aeruginosa is most commonly associated with MC-LR production. These blooms are increasing in occurrence in lakes, ponds, and other surface waters and, therefore, require efficient treatment methods to be removed from water supplies. Ionizing radiation technologies offer promising approaches for the removal of organic pollutants in water, including cyanotoxins and cyanobacteria. Gamma irradiation for the degradation of cyano-bacteria and toxins is effective for overall MC-LR degradation as well as reducing cell concentrations. However, gamma irradiation technology involves use of radioactive isotopes and, therefore, may not feasible commercially from a security perspective. Electron beam (eBeam) irradiation technology, which relies on regular electricity to generate highly energetic electrons, is able to achieve the same results without the confounding challenges of radioactive isotopes and related security issues. In this critical review, the current state of the science concerning the remediation of MC-LR and M. aeruginosa with ionizing radiation technologies is presented and future necessary research is discussed.