Removal of <i>Phaeocystis Globosa</i> From Seawater via Polyvinylpyrrolidone‐Modified Pyrite Activated Persulfate

Phaeocystis globosa (P. globosa) is a highly motile and toxic harmful algal bloom (HAB) species in marine environments. The outbreak of P. globosa poses severe threats to aquaculture and coastal nuclear power safety and causes economic losses. Therefore, there is an urgent need to explore novel algal removal technologies to control P. globosa blooms. Herein, polyvinylpyrrolidone-modified pyrite (PVP-FeS₂) was synthesized as a catalyst to activate persulfate (PS) for removing P. globosa in seawater. The introduction of PVP effectively modulated the morphology, particle size, and catalytic performance of FeS₂. The results demonstrated that a system containing 0.3 g/L PVP-FeS₂ and 0.8 mM PS achieved 95.9% removal efficiency of P. globosa within 4 hours. The Fe and S species on the PVP-FeS₂ surface played critical roles in activating PS to generate hydroxyl radicals (·OH) for algal cell oxidation and produce iron hydroxides to promote the flocculation of algal cells. In addition, the PVP-FeS₂/PS system maintained the integrity of algal cells and avoided the release of large amounts of intracellular organic matter. More importantly, the PVP-FeS₂/PS system can simultaneously remove multiple HABs from seawater, and is expected to be applied in the field of emergency mitigation of red tide events.