Preparation of multifunctional PET membrane and its application in high-efficiency filtration and separation in complex environment

Nowadays, effluent treatment is a severe challenge mainly because of its complex composition, which includes oil, heavy metal ions, and dyes. Developing new intelligent membranes is one of the strategies to tackle these significant challenges in wastewater treatment. In this study, we fabricated asymmetric polyethylene glycol terephthalate (PET) membranes by grafting cross-linked poly (itaconic anhydride) (CL-PITA) nanoparticles onto the irradiated face. These nanoparticles were then functionalized with polyethyleneimine (PEI) and protonated with HCl to introduce numerous active electropositive amine groups. The fundamental purpose was to increase surface roughness, introduce numerous hydrophilic groups, and modify it to create a multi-functional PET membrane to separate complex environments. The promising results demonstrated that the protonated PET-g-ITA/DVB(10)-cat membrane exhibited excellent separation efficiencies (SE) for water/light oil, water/heavy oil and oil-in-water (O/W) emulsion. Compared to PET-g-ITA/DVB(0)-cat, it showed superior performance in SE for O/W emulsion and flux decay for water/light oil after 10 cycles. More interestingly, owing to numerous positively charged active amino groups, the intelligent membrane exhibited a high removal rate of ca. 90% for anionic dye (methylene blue and congo red) and heavy metals (Cu2+ and Co2+), showing great potential in complex water treatment environments. The heavy metal ions, organic dyes, and organic solvents that existed in wastewater either in layered mixture or in emulsion leaded to air pollution as well as surface water and groundwater contamination, and have posed a significant threat to ecological equilibrium and human health due to their high accumulation, chemical stability, and nonmetabolizable feature. Multifunctional PET-g-ITA/DVB-cat can be employed as intelligent membrane for on-demand separation of water/heavy oil, water/light oil, and water-oil emulsions, while also for heavy metal ions and organic dyes adsorption. This separation technology can promote wastewater recycling, reducing pollution risks to humans and the environment.