# Preparation of NaA Zeolite Composite Polyacrylonitrile Membranes (TiO2-NaA@PANMs) Doped with TiO2 and Adsorption Study of Sr2+

## TL;DR

This study develops a composite membrane for efficiently removing strontium ions from nuclear wastewater using electrospinning and adsorption techniques.

## Contribution

A novel TiO2-doped NaA@PAN composite membrane is introduced for enhanced Sr2+ adsorption in nuclear wastewater treatment.

## Key findings

- The membrane achieved an equilibrium Sr2+ adsorption capacity of 55.00 mg/g at pH 6.0.
- The theoretical saturated adsorption capacity was 80.89 mg/g at 298 K.
- The membrane retained 81.60% Sr2+ removal efficiency after three regeneration cycles.

## Abstract

As a rarefied metallic element, strontium (Sr) is susceptible to significant environmental radioactive contamination risks during industrial mining and refining processes. In this study, NaA molecular sieves were prepared by alkali excitation using synthetic powders, which were homogeneously blended with the polyacrylonitrile (PAN) matrix, and nanoscale TiO2 reinforcing phases were introduced. Finally, composite separation membranes (TiO2-NaA@PANMs) with stable adsorption properties were constructed by electrostatic spinning technology. The micro-morphology and interfacial properties were characterized by SEM, XRD, and FT-IR systems. The adsorption experiments demonstrated that the equilibrium adsorption capacity of the system for Sr2+ reached 55.00 mg/g at the optimized pH = 6.0, and the theoretical saturated adsorption capacity at 298 K was 80.89 mg/g. The isothermal process conformed to the Langmuir’s model of monomolecular layer adsorption, and the kinetic behavior followed the quasi-secondary kinetic equation. Following three cycles of regeneration by elution with a 0.3 mol/L sodium citrate solution, the membrane material exhibited 81.60% Sr2+ removal efficacy. The composite membrane passages exhibited remarkable potential for utilization in engineering applications involving the treatment of complex nuclear wastewater.