title: Using H2O2treatments for the degradation of cyanobacteria and microcystins in a shallow hypertrophic reservoir.
abstract: Toxins produced by cyanobacteria in freshwater ecosystems constitute a serious health risk worldwide for humans that may use the affected water bodies for recreation, drinking water, and/or irrigation. Cyanotoxins have also been deemed responsible for loss of animal life in many places around the world. This paper explores the effect of H2O2treatments on cyanobacteria and microcystins in natural samples from a hypertrophic reservoir in microcosm experiments. According to the results, cyanobacteria were more easily affected by H2O2than by other phytoplanktonic groups. This was shown by the increase in the fractions of chlorophyll-a (a proxy for phytoplankton) and chlorophyll-b (a proxy for green algae) over total phytoplankton pigments and the decrease in the fraction of phycocyanin (a proxy for cyanobacteria) over total phytoplankton pigments. Thus, while an overall increase in phytoplankton occurred, a preferential decrease in cyanobacteria was observed with H2O2treatments over a few hours. Moreover, significant degradation of total microcystins was observed under H2O2treatments, while more microcystins were degraded when UV radiation was used in combination with H2O2. The combination of H2O2and ultraviolet (UV) treatment in natural samples resulted in total microcystin concentrations that were below the World Health Organization limit for safe consumption of drinking water of 1 μg/L. Although further investigation into the effects of H2O2addition on ecosystem function must be performed, our results show that the application of H2O2could be a promising method for the degradation of microcystins in reservoirs and the reduction of public health risks related to the occurrence of harmful algal blooms.
authors: Department of Civil Engineering, University of Thessaly, Volos, Greece.
authors: Theodoti
authors: T
authors: Papadimitriou
authors: Department of Ichthyology and Aquatic Environment, University of Thessaly, Volos, Greece.
authors: Konstantinos
authors: K
authors: Kormas
authors: Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA.
authors: Dionysios D
authors: DD
authors: Dionysiou
authors: Department of Civil Engineering, University of Thessaly, Volos, Greece. laspidou@uth.gr.
authors: Chrysi
authors: http://orcid.org/0000-0001-5225-4844
authors: C
authors: Laspidou
mesh_terms: D000458:Cyanobacteria / Q000187:drug effects*; D005618:Fresh Water / Q000382:microbiology*; D006115:Greece; D057097:Harmful Algal Bloom; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D060106:Lakes / Q000382:microbiology; D052998:Microcystins / Q000737:chemistry*
chemical_list: D052998:Microcystins; D006861:Hydrogen Peroxide
keywords: H2O2; Harmful algal blooms; Microcystins; Phycocyanin; Phytoplankton pigments; Reservoir; UV