Exploring the photocatalytic inactivation mechanism of Microcystis aeruginosa under visible light using Ag3PO4/g-C3N4

• Published in: Environmental science and pollution research international Vol. 29; no. 20; pp. 29993 - 30003
• Main Authors: Sun, Shiquan, Tang, Qingxin, Zhou, Lean, Gao, Yang, Zhang, Wei, Liu, Wang, Jiang, Changbo, Wan, Junli, Zhou, Lu, Xie, Min
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2022; Springer Nature B.V
• Subjects: Algae; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Carbon nitride; Catalytic activity; Cell walls; Cytology; Deactivation; Earth and Environmental Science; Ecotoxicology; Electrolytic cells; Environment; Environmental Chemistry; Environmental Health; Environmental science; Inactivation; Irradiation; Light intensity; Luminous intensity; Membrane permeability; Microcystis; Phosphates; Photocatalysis; Photodegradation; Photosynthesis; Proteins; Radiation; Reactive oxygen species; Research Article; Silver compounds; Waste Water Technology; Water Management; Water pollution; Water Pollution Control; Visible light photocatalysis; g-C; Cell damage; Ag; N; PO
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-17857-w

In this work, a series of Ag 3 PO 4 /g-C 3 N 4 (AG) photocatalysts were synthesized. After characterizing the properties, the effects of mass ratio, light intensity, and material dosages on photodegradation were investigated. The material with a 1/2 mass ratio of Ag 3 PO 4 /g-C 3 N 4 showed the highest photocatalytic activity under visible light, and the removal efficiency reached 90.22% for an initial suspended algae concentration of 2.7 × 10 6 cells/mL, 0.1 g of AG, and 3 h of irradiation. These results showed that the conductivity was increased while the total protein and COD contents of the algae suspension were declined rapidly. In contrast, the variations in the malondialdehyde (MDA) level suggested that the algae cell wall was severely damaged and that selective permeability of the membrane was significantly affected. A possible photocatalytic mechanism was proposed and •O 2 − was shown to be the major reactive oxygen species in the photocatalysis. In summary, during the visible light photocatalytic process, the cell structure was destroyed, which caused the leakage of electrolyte, the inactivation of protein, and the inhibition of photosynthesis; finally, the cells died. This study provides a reference for photodegradation of algae pollution in water bodies.