Harvesting of different microalgae through 100-μm-pore-sized screen filtration assisted by cationic polyacrylamide and specific extracellular organic matter

•Different microalgae species were aggregated with cationic polyacrylamide (CPAM).•Retention varied with the extracellular organic matters (EOM) characteristics.•High retention was positively related to high negative charge density of EOM.•High ratio of high-molecular weight EOM fractions also improved the retention.