Enhanced Microcystin-LR Removal from Humic Acid-Rich Water using MIL-101(Fe)-coated TiO2 Photocatalysis

Microcystin-LR is a toxic cyanobacterial peptide posing a threat to human and animal health. The presence of humic acids (HA) in water can inhibit the degradation of microcystin-LR, making its removal more challenging. This study proposes using MIL-101(Fe)-coated TiO2 as a photocatalyst to degrade microcystin-LR and diminish the inhibitory effect of HA.

MIL-101(Fe) is a metal-organic framework with a high surface area and excellent stability. TiO2 is a well-known photocatalyst that can degrade organic pollutants under UV irradiation. The combination of MIL-101(Fe) and TiO2 can enhance the photocatalytic activity and selectivity of the system.

The MIL-101(Fe)-coated TiO2 was synthesized using a solvothermal method and characterized using X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The photocatalytic activity of the system was evaluated by degrading microcystin-LR in HA-rich water under UV irradiation.

The results showed that MIL-101(Fe)-coated TiO2 exhibited a higher photocatalytic activity than pure TiO2 in degrading microcystin-LR. The addition of HA reduced the degradation efficiency of both TiO2 and MIL-101(Fe)-coated TiO2. However, the inhibition effect of HA on MIL-101(Fe)-coated TiO2 was lower than that on pure TiO2.

The study suggests that MIL-101(Fe)-coated TiO2 can effectively degrade microcystin-LR and diminish the inhibitory effect of HA. The system has potential applications in water treatment for removing microcystin-LR from HA-rich water.