Performance of an optimized Zr-based nanoparticle-embedded PSF blend hollow fiber membrane in treatment of fluoride contaminated water

- An optimized Zr-based nanoparticle-embedded PSF blend hollow fiber membrane was developed for effective defluoridation.
- The qmax of static fluoride adsorption at neutral pH was 60.65 mg/g.
- The blend membrane efficiently removed fluoride by dynamic adsorption.
- The uptake of fluoride by the membrane is probably due to ion-exchange with between fluoride and sulfate.

Consumption of water that has excessive fluoride can cause adverse health impacts on human beings. A Zr-based nanoparticle-embedded PSF blend hollow fiber membrane was successfully prepared and optimized for removal of fluoride from the aqueous solution. Both static and dynamic adsorption of fluoride on the membrane was investigated. It was showed that the membrane could effectively remove fluoride within a wide pH ranging from 3 to 10. At neutral pH, the adsorption equilibrium was reached within 24 h. The maximum adsorption capacity of the optimized membrane was 60.65 mg/g, much higher than many commercial adsorbents. The presence of NO3−, SiO32− or HA has insignificant effects on the fluoride removal. However, the removal was retarded as the concentration of HCO3− or PO43− was increased. Furthermore, the membrane could remove fluoride efficiently through the continuous filtration, even in presence of natural organic matters. The spent membrane could be regenerated and then reused for the removal of fluoride with great efficiency. The adsorption history could be well described by an intraparticle diffusion model. The XPS analysis showed that the adsorption of fluoride was mainly associated with the ion-exchange between SO42− and F− ions. Finally, the toxicity analysis revealed that the treated water was safe for human consumption.