Effect of pre-chlorination on Microcystis aeruginosa cell integrity and microcystins removal

High nutrient input into waterbodies increases potentially toxic cyanobacteria blooms. Pre-chlorination treatment is excellent for cyanobacterial cell inactivation and dissolved cyanotoxins removal in water supply sources. This study aims to evaluate the pre-chlorination effect treatment on Microcystis aeruginosa cell integrity and its hepatotoxins (microcystins, MC) release and degradation on a laboratory scale. Loss of cell integrity is observed with increasing chlorine concentration. The maximum cell permeability without cell disintegration occurs at 2.5 mg Cl2 L−1. Degradations up to 70% and chlorophyll-a reductions over 70% are observed after 60 min exposure, with complete degradation at 2.5 and 3 mg Cl2 L−1. However, chlorine (Cl2) exposure over 40.66 mg min L−1 is required for microcystins MC-LR (i.e. radicals: leucine (L) and arginine (R)) and MC-RR (i.e. radicals: arginine and arginine) oxidation oxidation to concentrations below the legislation value for water potability.