Electrochemical inactivation of cyanobacteria and microcystin degradation using a boron-doped diamond anode — A potential tool for cyanobacterial bloom control Andrej Meglič 1 , Anja Pecman 2 , Tinkara Rozina 3 , Domen Leštan 2 , Bojan Sedmak 4, ⁎ 1. Arhel Ltd., Pustovrhova c. 63, SI-1000 Ljubljana, Slovenia. E-mail: andrej.meglic.info@gmail.com 2. Centre for Soil and Environmental Sciences, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia 3. Envit Ltd., Vojkova c. 63, SI-1000 Ljubljana, Slovenia 4. Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Večna pot 111, SI-1000 Ljubljana, Slovenia ARTICLE INFO ABSTRACT Article history: Received 15 June 2015 Revised 21 October 2015 Accepted 19 February 2016 Available online 20 May 2016 Cyanobacterial blooms are global phenomena that can occur in calm and nutrient-rich (eutrophic) fresh and marine waters. Human exposure to cyanobacteria and their biologically active products is possible during water sports and various water activities, or by ingestion of contaminated water. Although the vast majority of harmful cyanobacterial products are confined to the interior of the cells, these are eventually released into the surrounding water following natural or artificially induced cell death. Electrochemical oxidation has been used here to damage cyanobacteria to halt their proliferation, and for microcystin degradation under in-vitro conditions. Partially spent Jaworski growth medium with no addition of supporting electrolytes was used. Electrochemical treatment resulted in the cyanobacterial loss of cell-buoyancy regulation, cell proliferation arrest, and eventual cell death. Microcystin degradation was studied separately in two basic modes of treatment: batch-wise flow, and constant flow, for electrolytic-cell exposure. Batch-wise exposure simulates treatment under environmental conditions, while constant flow is more appropriate for the study of boron-doped diamond electrode efficacy under laboratory conditions. The effectiveness of microcystin degradation was established using high-performance liquid chromatography–photodiode array detector analysis, while the biological activities of the products were estimated using a colorimetric protein phosphatase-1 inhibition assay. The results indicate potential for the application of electro-oxidation methods for the control of bloom events by taking advantage of specific intrinsic ecological characteristics of bloom-forming cyanobacteria. The applicability of the use of boron-doped diamond electrodes in remediation of water exposed to cyanobacteria bloom events is discussed. © 2016 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. Keywords: Cyanobacterial bloom control Boron-doped diamond anode Electro-oxidation Microcystin degradation Protein phosphatase-1 inhibition Water remediation JOURNAL OF ENVIRONMENTAL SCIENCES 53 (2017) 248 – 261 ⁎ Corresponding author. E-mail: bojan.sedmak@nib.si (Bojan Sedmak). http://dx.doi.org/10.1016/j.jes.2016.02.016 1001-0742/© 2016 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. Available online at www.sciencedirect.com ScienceDirect www.elsevier.com/locate/jes