Fig. 1. Synthetic route of UHMWPE-HO fiber

Fig. 2. Digital images of (a) UHMWPE-PAA, (b) UHMWPE-PAM, (c) UHMWPE-P AA/NH₂OH, (d) UHMWPE-PAM/NH₂OH, and (e) UHMWPE-HO after adsorption of Fe(III) ions

Fig. 3. SEM images of (a) and (a') original UHMWPE fiber, (b) and (b') UHMWPE-HO fiber, and (c) and c') the Cu (II)-loaded UHMWPE-HO fibers: (a), (b) and (c) magnification 2 000×, (a'), (b') and (c') magnification 400×

Fig. 4. ATR-FTIR spectra of (a) UHMWPE, (b) UHMWPE-g-PAA, (c) (UHMWPE-g-PAA)-g-PAM, and (d) UHMWPE-HO fibers

Fig. 5. Thermogravimetric analysis curves of the UHMWPE, UHMWPE-g-PAA, (UHMWPE-g-PAA)-g-PAM, and UHMWPE-HO fibers: (a) TG; (b) DTG

Fig. 6. Effects of (a) pH, (b) reaction time, and (c) initial concentration on absorption performance of UHMWPE-HO fibers; (d) adsorption ability of UHMWPE-HO fibers at different regeneration cycles

Fig. 7. Effects of absorbent dosage on (a) residual concentration, and (b) removal ratio for Cu (II), Co(II), and Ni(II) ions in mixed solution