Tailoring Mesoporous Y-Zeolite Molecular Sieve for Effective Removal of Micropollutants from Water

Abstract

Overuse and misuse of antibiotics have led to persistent antibiotic residues in water, challenging conventional remediation approaches. This study developed a tailored molecular sieve material, i.e., mesoporous Y-zeolite (M-Y zeolite), through hydrothermal synthesis for tetracycline (TC) removal from simulated and real water matrices. The average pore size of M-Y zeolite was 3.16 nm, more than 1.7 times the second-widest dimension of the targeted TC molecule (0.81 nm), allowing for effective adsorption. With a specific surface area of 516 m² g^–1, M-Y zeolite achieved a maximum adsorption capacity of 88 mg g^–1. The pseudo-second-order and Freundlich models indicated that adsorption occurred on a multilayer heterogeneous surface through chemisorption. The intraparticle diffusion model indicated that the adsorption process was governed by both liquid film diffusion and intraparticle diffusion. Mechanistic studies identified pore filling, complexation, and electrostatic interactions as the main adsorption mechanisms. After four regeneration cycles, the M-Y zeolite retained 66% of its initial adsorption capacity. In real water tests, removal efficiency slightly declined (4–14%) at 10 mg L^–1 TC due to competing ions and organic matter but remained >99% at 0.1 and 1 mg L^–1 TC. These findings offer a promising mesoporous material for antibiotic removal, marking a significant advancement in water treatment.