Transforming waste into value: High-performance hollow fiber adsorbents from municipal solid waste incinerator bottom...

This study pioneers a novel approach to valorize municipal solid waste incinerator bottom ash (IBA) by synthesizing high-performance hollow fiber adsorbents. A combined phase inversion and sintering method was employed, systematically investigating the influence of key synthesis parameters (IBA content, ball milling, spinneret diameter, solution flow rates, and sintering temperature) on the resulting fiber morphology and performance. The physicochemical properties of the synthesized hollow fibers were characterized using scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, and Fourier-transform infrared spectroscopy (FTIR). Optimal synthesis conditions were identified: a spinning solution of IBA, N-methyl-2-pyrrolidone (NMP), polyvinylpyrrolidone (PVP), and polyethersulfone (PESf) in a 50:44:1.4:4.6 wt ratio, ball-milled for homogeneity, extruded through a 3 mm spinneret at 7 mL/min, and sintered at 1150 °C. The resulting hollow fibers exhibited a well-defined concentric circular structure with finger-like inner and outer layers and a dense sponge-like middle layer. The adsorption performance of these novel adsorbents was evaluated using Acid Blue 93 (AB93) as a model pollutant, achieving an adsorption capacity of 192.8 ± 2.1 mg/g with a removal efficiency of 96.4 ± 1.05 % under specific conditions. The X-ray powder diffraction (XRD) analysis revealed the existence of Ca(OH)₂ in the ash, which enabled a reduction in the sintering temperature to 1150 °C, thereby lowering energy consumption and production cost. This work demonstrates the feasibility of converting incinerator bottom ash into valuable adsorbent materials, offering a sustainable waste management solution.