The remediation of water contaminated by persistent antibiotic residues necessitates advanced treatment technologies that combine high removal efficiency with facile operational recovery. This study presents the development of a magnetically retrievable composite adsorbent, synthesized via ionic cross-linking co-assembly of pre-formed Fe₃O₄ nanoparticles and ZIF-8 nanocrystallites with industrial-grade chitosan. Comprehensive characterization (PXRD, FTIR, SEM, BET) confirmed the successful integration of components into a cohesive, macroporous bead architecture with robust mechanical stability. Process optimization utilized a hierarchical approach: initial univariate screening identified key operational parameters, which subsequently informed a multivariate Box-Behnken design. The derived second-order response surface model (R² = 0.9930) provided a benchmark for comparison against multiple machine learning algorithms, including support vector regression (SVR), Artificial Neural Networks, and tree-based ensembles. The SVR model demonstrated superior predictive accuracy (R² = 0.9994, RMSE = 0.434) and reliable extrapolation (predicted R² = 0.9618), enabling precise parameter optimization. At the identified optimum conditions (10 mg L⁻¹ tetracycline, 300 mg L⁻¹ sorbent, 135 min, pH 8.5), a sequestration efficiency of 74.04% was achieved. The composite exhibited excellent reusability, retaining > 60% of its initial capacity over five consecutive adsorption-desorption cycles, facilitated by rapid magnetic separation. Kinetic studies revealed that uptake followed a pseudo-second-order model (R² = 0.991), indicative of chemisorption, with an experimental maximum capacity of 24.5 mg g⁻¹. By unifying low-cost materials, a clear structure-property relationship, and a sophisticated modeling framework, this work provides a practical, magnetically separable adsorption system for the targeted removal of tetracycline in engineered water treatment.
Amanizadegan et al. (Thu,) studied this question.