Mechanism of algal removal in the EP-BiOBr/ZnFe2O4 floating photocatalytic system

HU Lei; ZHANG Dong-yuan; DING Ning; LIU Hong

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China Environmental Science ›› 2026, Vol. 46 ›› Issue (3) : 1554-1567.

Environmental Ecology

Mechanism of algal removal in the EP-BiOBr/ZnFe₂O₄ floating photocatalytic system

HU Lei¹, ZHANG Dong-yuan¹, DING Ning², LIU Hong¹

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Abstract

A floating-type EP-BiOBr/ZnFe₂O₄ (EP-BFO) photocatalyst with a type-II heterojunction was successfully synthesized via the hydrothermal method. Characterization techniques including SEM, XRD, XPS, and UV-Vis DRS were employed to analyze the morphology, elemental composition, and chemical valence states of the photocatalyst. Results indicate that EP-BFO exhibits a three-dimensional porous structure, broad spectral response (200~700nm), and an optimized band structure (Eg = 2.08eV). Its oxygen vacancies and heterojunction interface effectively promote photogenerated charge separation. The removal efficiency of EP-BFO against Microcystis aeruginosa under visible light was investigated, along with its removal mechanism. Results demonstrated that EP-BFO achieved a removal rate of 93.6% for Microcystis aeruginosa under visible light, with a reaction rate constant (0.4191h^-1) significantly superior to that of single-component catalysts. When tested in complex aquatic environments containing 10mg/L humic acid or fulvic acid, EP-BFO still maintained an 82% removal rate. Radical scavenging experiments indicated that superoxide radicals (·O₂^-) and holes (h⁺) were the primary active species. Concurrently, the active species generated during photocatalysis caused damage to algal cell membranes (ion leakage, MDA accumulation) and photosynthetic systems (degradation of phycobiliproteins) through oxidative processes.

Key words

photocatalytic / algae removal / BiOBr/ZnFe₂O₄ / heterojunction / Microcystis aeruginosa

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HU Lei, ZHANG Dong-yuan, DING Ning, LIU Hong. Mechanism of algal removal in the EP-BiOBr/ZnFe₂O₄ floating photocatalytic system[J]. China Environmental Science. 2026, 46(3): 1554-1567

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