Degradation of cyanotoxins (microcystin) in drinking water using photoelectrooxidation

A rapid and efficient method using electroporation for releasing intracellular microcystin toxins from cultured and naturally occurring cyanobacterial cells in lake water

In cyanotoxin measurements, effective release of intracellular cyanotoxins through cell lysis is pivotal. The conventional method for cell lysis is repeated freeze-thaw (F-T), which has several disadvantages, including poor reproducibility since it is operator and equipment dependency and time-consuming. In this study, a rapid and sensitive method was developed using irreversible electroporation, reducing quantification time by over 6 h compared to F-T. Focusing on microcystins (MCs), we developed the most optimal electroporation medium (50 mM Tris (pH 7.0) with 0.5 % SDS) and determined the optimal intensity of electroporation using Microcystis culture. Microcystis cell rupture was validated by scanning electron microscopy. COMSOL simulations mirrored experimental conditions. Compared to F-T, this new method generated an average 13.7 % (6.7 ppb) more MCs from lake water samples (p ≥ 0.05). This innovation, surpassing the time-consuming F-T process, emerges as a valuable tool for timely decision-making in water safety advisory and cyanotoxin management in various settings.

Efficient electrochemical remediation of microcystin-LR in tap water using designer TiO2@carbon electrodes

Microcystin-leucine arginine (MC-LR) is the most abundant and toxic secondary metabolite produced by freshwater cyanobacteria. This toxin has a high potential hazard health due to potential interactions with liver, kidney and the nervous system. The aim of this work was the design of a simple and environmentally friendly electrochemical system based on highly efficient nanostructured electrodes for the removal of MC-LR in tap water. Titania nanoparticles were deposited on carbon (graphite) under a simple and efficient microwave assisted approach for the design of the electrode, further utilized in the electrochemical remediation assays. Parameters including the applied voltage, time of removal and pH (natural tap water or alkaline condition) were investigated in the process, with results pointing to a high removal efficiency for MC-LR (60% in tap water and 90% in alkaline media experiments, under optimized conditions).