Document Type

Article

Publication Date

Winter 2-9-2026

Abstract

This study presents the development of a novel multifunctional adsorbent Cu-BTC (HKUST-1)/Zeolite A4 composite functionalized with tannic acid—for the efficient removal of toxic heavy metal ions (Pb²⁺, Cd²⁺, Cr(VI)) from aqueous solutions. The composite was synthesized via a solvothermal process and systematically characterized by XRD, FTIR, SEM-EDS, and BET surface area analysis. The resulting material exhibited a high specific surface area (1050 m²/g), a hierarchical pore structure, and a homogeneous distribution of active sites. Batch adsorption experiments revealed superior adsorption capacities of 220 mg/g for Pb²⁺, 180 mg/g for Cd²⁺, and 150 mg/g for Cr(VI) at pH 6, surpassing those of the individual components.Adsorption kinetics followed a pseudo-second-order model (R² > 0.98), indicating chemisorption dominance through electron sharing or exchange mechanisms. Isotherm analysis demonstrated a strong fit to the Langmuir model (R² > 0.99), confirming monolayer adsorption on homogeneous surface sites. The proposed adsorption mechanism involves coordination to open metal sites in Cu-BTC, ion exchange within Zeolite A4 micropores, and chelation by the polyphenolic groups of tannic acid. ANOVA statistical analysis confirmed the significant influence of pH and contact time (p < 0.01) on adsorption efficiency.Reusability tests showed 85% retention of adsorption capacity after five cycles, highlighting the composite's structural stability and cost-effectiveness. Comparative cost analysis further demonstrated a 62–93% reduction in treatment cost versus conventional adsorbents. These findings position the tannic acid-functionalized Cu-BTC@Zeolite A4 composite as a promising candidate for scalable, sustainable, and high-performance heavy metal remediation in real-world wastewater treatment systems.

Download

Share

COinS