Thiol-rich and ion-imprinted alginate hydrogel as a highly adsorptive and recyclable filtration membrane for rapid and selective Sr(II) removal

Radionuclides such as strontium 90, 90Sr, pose severe threats to the environment and humans since wide application of nuclear power plants around world. In environment, rapid remediation Sr2+ contaminated water still remains challenging. The current study developed an economical biomaterial-based hydrogel adsorbent with excellent adsorption performance achieved by ion-imprinting abundant thiol groups, which was adaptable adsorptive filtration membrane for efficient purification polluted water. synthesized via a three-step route based on sodium alginate (SA). First, SA emulsified converted complexation (SA-Sr); secondly, thiol-rich carboxyethyl grafted pentaerythritol tetrakis (thioglycolic acid) ester (PA) click chemistry used covalently crosslink (SA-PA-Sr) groups simultaneously introduced lastly, Sr2+-imprinted (SA-PA-H) obtained acid elution SA-PA-Sr hydrogel. SA-PA-H demonstrated superior Sr2+adsorption capacity (∼151.7 mg/g), kinetics following pseudo-second order, rate constant 0.669 g mg−1 min−1, selectivity Sr2+, value ∼ 1.14 × 103 mL g−1 when adsorbing 10 ppm from concentrated (100 ppm) solutions competitive ions (Na+ or Mg2+). maintained over pH range (4–10) temperatures (25–40 °C). mechanism attributed prevalent bindings Sr2+imprinted cavities. Moreover, showed high elasticity storage shear modulus kPa at low strains, full self-recovery after being repeatedly damaged large strains . This allowed be adapted vacuum filtration, giving removal efficiency (>99.2%) under liquid flux (∼40 L m-2h−1). addition, could regenerated washing four consecutive adsorption–desorption cycles, drop in minor (53.51% 36.88% 100 Sr2+). investigation novel advantageous cost, performance, processability sustainability, applicable complete decontamination wastewater filtration.