Anti-algal activity of Fe2O3–TiO2 photocatalyst on Chlorella vulgaris species under visible light irradiation. (March 2020)

• Record Type: Journal Article
• Authors: Baniamerian, Hamed; Tsapekos, Panagiotis; Alvarado-Morales, Merlin; Shokrollahzadeh, Soheila; Safavi, Maliheh; Angelidaki, Irini
• Is Part Of: Chemosphere. Volume 242(2020)
• Publication Date: 2020-03
• Subjects: Seawater pre-treatment -- Photocatalysis -- Visible light -- Biofouling -- Microalgae -- Chlorella vulgaris; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.125119
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Many industries located in coastal areas use a large amount of seawater. Algal biofouling can be a major problem that hinders the efficiency of these industrial facilities. In most cases, seawater requires algal removal pre-treatment to avoid or mitigate biofilm formation. To remediate green microalgae, Fe2 O3 –TiO2 nanoparticles with 2.5% w/w Fe2 O3 were applied as a visible light driven photocatalyst. The anti-algal activity of the photocatalytic pre-treatment using green microalgae, Chlorella vulgaris was tested. The experiments were carried out in freshwater, artificial seawater, and real seawater. Effect of photocatalyst dosage, visible light intensity, and water salinity on the removal of microalgae was investigated. The highest inactivation efficiency of Chlorella vulgaris was achieved under 55 W/m 2 visible light irradiation when 0.25 g/L of Fe2 O3 –TiO2 photocatalyst was used. The photocatalytic removal kinetics of Chlorella vulgaris followed the pseudo first order Langmuir-Hinshelwood model. The results revealed that the efficiency of photocatalytic removal of algae decreased with increasing of seawater salinity. The anti-algal activity of Fe2 O3 –TiO2 nanoparticles was attributed to the generation of reactive oxygen species (ROS) through the photocatalytic process. H + radical was shown to be the most important ROS that nanoparticles produced in the aqueous media. Using Fe2 O3 –TiO2 nanoparticles in photocatalytic pre-treatment could be an efficient environmental-friendly method for micro-algal remediation in seawater under visible light. Highlights: Anti-algal activity of Fe2 O3 –TiO2 NPs was investigated in fresh and saline water. TiO2 –Fe2 O3 NPs achieved a high removal rate of algal cells (99.8%) within 24 h. Anti-algal activity of NPs was 31.6% higher in fresh water than high-salinity water. Non-toxic alternative for prevention of algal fouling was presented. H + radical was dominant ROS species produced during photocatalysis.