Efficient removal and action mode of low-cost zinc-based metal-azolate frameworks regulated by ligand on Microcystis aeruginosa

Metal-organic frameworks (MOFs) had been demonstrated efficacy in the inhibition of Microcystis . However, the influence of ligand selection on this inhibitory effect remains to be fully elucidated. The metal-azolate framework (MAF) is a subclass of the MOF. In this study, the methyl groups in the ligands were adjusted based on MAF-7, and 3-methyl-1,2,4-triazole (Hmtz), 1-methyl-1,2,4-triazole (Mhtz), and 1,2,4-triazole (Tz) were used as ligands to conduct comprehensive research and verification on the effects of zinc-based MAFs (Zn-MAFs) on the removal of Microcystis aeruginosa ( M. aeruginosa ). Through structural characterization, it was found that the differences in methyl groups led to different Zn-MAFs characteristics and affected their M. aeruginosa removal performance. The anti- Microcystis characteristics and mode of action of Zn-MAFs were systematically studied and compared with H 2 O 2 . The findings indicated that the inhibitory effect of Zn-Tz on M. aeruginosa was significantly enhanced, and the inhibitory effect produced within the unit cost is the highest, the comprehensive cost is 219 times lower than that of the reported MAF-7. A comprehensive evaluation of the underlying mechanism revealed that the presence of Zn-Tz resulted in the deterioration of the intracellular photosystem of M. aeruginosa cells, the degradation of the cell membrane, and the damage of ribosomes. Concurrently, the results of the zebrafish acute toxicity test indicated that, in comparison with the grade III acute toxicity of H 2 O 2 , Zn-MAFs exhibited no discernible acute toxicity. This study identified a novel type of low-cost and safe MAF, providing a promising method for the regulation of cyanobacterial blooms.