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The issue of antibiotic residue and contamination has attracted significant attention. Most of the existing degradation methods are inefficient and costly. Photocatalytic technology is an up-and-coming method. Titanium dioxide (TiO 2 ) is a photocatalyst widely used to degrade the residual antibiotics in water under ultraviolet (UV) irradiation. However, its application efficiency under visible light is poor, owing to its wide bandgap. This paper reports the successful synthesis of Ag 2 S/TiO 2 composite nanofiber membranes through electrospinning and hydrothermal processes, and adsorption and photocatalytic removal of tetracycline (TC) under visible light irradiation. Ag 2 S/TiO 2 showed excellent photocatalytic property for TC degradation compared with Ag 2 S and TiO 2 , and the efficiency was up to 70.54%. It kept high photocatalytic performance after five cycles. The detailed mechanism of TC degradation by Ag 2 S/ TiO 2 was also proposed based on the radical trapping experiment and the analysis of degradation intermediates. Benefiting from the large surface area, effective photocatalysis under visible light irradiation, and excellent recyclability, Ag 2 S/TiO 2 composite fiber membranes are promising in the treatment of antibiotic wastewater.

Lanthanun oxide (La2O3) is a lanthanum chemical compound incorporates a sensible anionic complexing ability; however, it lacks stability at a low pH scale. Biochar fibers will give the benefit of their massive space and plethoric uses on the surface to support a metal chemical compound. Herein, wet spinning technology was used to load La3+ onto sodium alginate fiber, and to convert La3+ into La2O3 through carbonization. The La2O3-modified biochar (La-BC) fiber was characterized by SEM, XRD and XPS, etc. An adsorption experiment proved that La-BC showed an excellent adsorption capacity for chromates, and its saturation adsorption capacity was about 104.9 mg/g. The information suggested that the adsorption was in step with both the Langmuir and Freundlich models, following pseudo-second-order surface assimilation mechanics, which showed that the Cr (VI) adsorption was characterized by single-phase and polyphase adsorption, mainly chemical adsorption. The thermodynamic parameters proved that the adsorption process was spontaneous and endothermic. The mechanistic investigation revealed that the mechanism of the adsorption of Cr (VI) by La-BC may include electrostatic interaction, ligand exchange, or complexation. Moreover, the co-existing anions and regeneration experiments proved that the La-BC is recyclable and has good prospects in the field of chrome-containing wastewater removal.