Effective water disinfection using magnetic barium phosphate nanoflakes loaded with Ag nanoparticles

In this work, novel magnetic nanocomposites, Fe3O4@Ba-3(PO4)(2) (denominated FBP) nanoflakes loaded with Ag nanoparticles (NPs) (denominated FBPA), were reported for cleaning E. coli from water. FBPA with 1 wt% Ag (denominated FBPA1) showed a higher adsorption efficiency (94%) than FBPA with 10 wt% Ag (denominated FBPA10), for water heavily contaminated with E. coli (5 x 10(8) CFU/mL), both at a dosage of 1 g/L within 10 min. Importantly, the loaded Ag NPs can greatly improve the disinfection effect of FBP due to the great antimicrobial activity of Ag NPs via the released Ag+. Confocal fluorescent images and dilution plating results showed that similar to 100% of E. coli could be inactivated by FBPA1 within 10 min. The calculated disinfection capacity was higher than some other materials. Three co-existed salts in solutions decreased the disinfection efficiency of FBPA1 to be similar to 67% (NaCl), similar to 59% (CaCl2), and similar to 41% (MgCl2). Furthermore, FBPA1 can be reclaimed via a magnet to be reused. FBPA1 maintained an adsorption efficiency of 86%, disinfection effect of 70%, and similar to 90% of loaded Ag NPs after the fifth recover and reuse cycle. (C) 2019 Elsevier Ltd. All rights reserved.