Synergistic coupling of photocatalytic optical fibers with chloride ion adsorption fibers to remove trichloroethylene from polluted water

Photocatalytic optical hollow fibers (POHFs) coupled with spiral-shaped Cl − adsorption fibers are used to remove trichloroethylene (TCE) from wastewater. The POHFs are hollow quartz tubes coated with Ti 3 C 2 T x -doped oxygen vacancy (OV)-rich BiOBr (BiOBr-OV). The photocatalyst coating enhanced the excitation light intensity onto the photocatalytic fiber surface. The hetero-junction between Ti 3 C 2 T x and BiOBr-OV reduced the bandgap and broadened spectral absorption range of the composite photocatalyst. The material increased the production of reactive · O 2 - and •OH species, thereby improving the degradation of TCE. Spiral-shaped Cl − adsorption fibers comprised of polyethersulfone loaded with ethylenediaminetetraacetic acid-grafted metal–organic framework (MOF-808-EDTA). Tertiary amine groups (−R 3 N) of MOF-808-EDTA exhibited superior Cl − adsorption capabilities. As the Cl − ion indirectly quenches the free radicals, its removal reduced the inhibitory effect of the photocatalytic products, further enhancing the efficiency of TCE degradation and removing its degraded byproducts. TCE, chemical oxygen demand, and Cl − ion removal rates are 98.75, 69.15, and 99.22 %, respectively. Intimate coupling of photocatalysis and ion adsorption provided an effective solution for efficient removal of TCE, its degradation products, and Cl − ions from wastewater.