Inhibition of growth for Microcystis aeruginosa by insertion of iron ion into biochar modified copper metal organic framework (Fe3O4-BC@Cu-MOF-74) under visible light

Abstract

Microcystis aeruginosa (M. aeruginosa) was a kind of harmful algae in various aquatic ecosystems, which has caused much public concern. The existing algae removal methods showed disadvantages such as incomplete algae removal and excessive capital investment. Based on the specificity of algal cells, insertion of iron ion into biochar-modified copper metal organic framework (Fe3O4-BC@Cu-MOF-74) was synthesized by biochar and MOF with the introduction of Fe3O4. Fe3O4-BC@Cu-MOF-74 was thin, porous and stable. C, O, Fe, and Cu were mainly contained, and it was characterized by peaks (111), (220), (331), (111), (400), (331) and (024) in crystal planes and C–O bonds, Cu–O bonds and O–H bonds were contained. Algal cell growth was significantly inhibited, with a growth inhibition efficiency of 32.21 % by Fe3O4-BC@Cu-MOF-74 under visible light. Chlorophyll-a was reduced by nearly 60 %. The high concentration of oxygen and hydroxyl radicals in the complex accelerated the oxidative process in cells, leading to oxidative stress, which triggered an increase in the concentration of relevant antioxidant enzymes, leading to an increase in soluble protein content. The presence of Cu2+, Fe2+ and Fe3+ could also attack and damage the cell membrane surface, leading to cell rupture and death. Fe3O4-BC@Cu-MOF-74 showed a promising application in the problem of inhibiting the growth of M. aeruginosa under visible light.