Cyanobacteria toxins and the current state of knowledge on water treatment options: a review

Abstract

Cyanobacteria toxins have quickly risen in infamy as important water contaminants that threaten human health. This paper provides a broad overview of cyanobacteria toxins and the current state of knowledge about water treatment options to reduce these toxins. The first part of the paper focuses on cyanobacteria as organisms and their ability to produce a variety of toxins, the proposed or accepted regulatory guidelines for these toxins, and common detection techniques. Then a review is presented of the past 25 years worth of work on cyanobacteria toxin removal using both conventional and advanced water treatment processes and operations. The paper concludes by identifying directions for future research required to advance the abilities of utilities and water treatment plant designers to deal with these toxins while long-term, watershed management and surveillance plans are developed and implemented. As well, some suggestions are provided for immediate steps that a water utility facing cyanobacteria blooms could take to minimize human exposure to these toxins. Key words: cyanobacteria, blue-green algae, microcystin, cylindrospermopsin, cyanotoxins, water treatment, membrane filtration, advanced oxidation, UV photolysis, drinking water.