Impact of chlorination on cell inactivation, toxin release and degradation of cyanobacteria of development and maintenance stage

•Characteristics of Microcystis at development and maintenance stage were compared.•Elevated cell-density and DOC at maintenance stage caused faster chlorine consumption.•Chlorine could completely inactive Microcystis of development and maintenance stage.•Possible reactive chlorinated-intermediates promoted toxin degradation at maintenance stage.•Sufficient chlorine exposure could completely degrade total toxin for Microcystis at both stages.