Polydopamine functionalized FeVO₄@PVDF ultrafiltration membrane with superior antifouling and detoxification properties

The poly (vinylidene fluoride) (PVDF) based filtration has become a popular technology for efficient wastewater treatment and desalination. However, these PVDF membranes are prone to fouling and increase their usage cost. To address these drawbacks our study demonstrates a self-polymerized polydopamine (PDA) functionalized PVDF membrane loaded with FeVO₄ through dead-end filtration blowing method with superior antifouling and visible light photocatalytic detoxification properties. Compared to pristine PVDF and FeVO₄@PVDF, the PDA-FeVO₄@PVDF demonstrated superior water flux, high BSA rejection and enhanced sulfamethoxazole detoxification efficiency. Addition of PDA and FeVO₄ increased the adhesion, roughness, and hydrophilicity of the membrane leading to improved membrane durability and anti-fouling. The flux recovery rate (FRR) of the PDA-FeVO₄@PVDF membrane was sustained very well even after 3 cycles with an FRR of 92.5 % compare to pure PVDF (72.5 %), and the irreversible fouling ratio (R_ir) was also significantly decreased for the PDA-FeVO₄@PVDF (7.4 %) compare to pristine PVDF (35.1 %). In addition, the prepared membrane has shown superior efficiency towards SMX with 94.3 % degradation within 3 h of visible light irradiation. Furthermore, based on the main ROS (OH^[rad], O₂^[rad]−, h⁺ and ¹O₂) and LC-ESI/MS analysis, the plausible degradation pathway was elucidated. The toxicity assessment analysis has shown that the significant detoxification of SMX was attained. In addition, DFT study revealed the strong interfacial interaction between PDA, FeVO₄ and PVDF responsible for the improved activity. Thus, the present study provides new insights into the preparation of modified hydrophobic PVDF ultrafiltration membranes with self-cleaning and detoxification attributes via visible light photodegradation.