Preparation of PEI/La2O3/Polypropylene fiber filter for household water purifiers and investigation of its phosphate reduction and bacterial control

It has been accepted that limiting phosphate is a prerequisite for bacterial inactivation in tap water. La 2 O 3 nanoparticles were loaded onto polypropylene (PP) fibers through the method of melt spinning. Hydrophilic modification of the adsorbent surface was performed using polyethyleneimine (PEI) to prepare PEI/La 2 O 3 /PP. The results indicated that the optimal loading amount of La 2 O 3 was 1 %, and the optimal concentration of PEI was 1 %. The successful loading of La 2 O 3 resulted in a roughened fiber surface and increased fiber diameters . After PEI modification the water contact angle was reduced from 98° to 50°. The pH zpc of PEI/La 2 O 3 /PP was determined to be 8.3. The co-existing ions have little effect on phosphate adsorption. Phosphate adsorption can be well described by Redlich-Peterson model with a maximum K R-P of 3.98 × 10 −5  L/mg. Adsorption kinetics fit well with the pseudo-second-order reaction equation. The activation energy (E a) is determined to be 57.9 kJ/mol, providing the evidence of chemical nature of the reaction involving phosphate ions on the surface of PEI/La 2 O 3 /PP. The PEI/La 2 O 3 /PP adsorbent can reduce the phosphate concentration in tap water to below 0.01 mg/L, leading to a reduction in Escherichia coli concentration from approximately 10,000 CFU/mL to around 10 CFU/mL. The survival rates of Escherichia coli in a multi-nutrient environment are higher than in a single phosphate source environment. Our research provides a new feasible approach for ensuring microbial water quality safety in household water purifiers.