Performance and Mechanistic Insights Into Gadolinium‐Modified Zirconium‐Based Metal–Organic Gels (MOG‐ZrGd) for Pulp Wastewater Treatment

ABSTRACT

A gadolinium‐modified zirconium‐based metal–organic gel (MOG‐ZrGd) was synthesized by a hydrothermal method to enhance the coagulation performance of Zr‐based gels for pulp wastewater treatment. Gd ^{3 +} was successfully incorporated into the Zr–BTC framework, generating synergistic Zr(IV)/Gd(III) active centers while preserving the gel's porous structure and thermal stability. Under optimized conditions, MOG‐ZrGd achieved 96.1% turbidity and 86.0% UV ₂₅₄ removal, while reducing coagulant dosage (1.1→0.9 g), settling time (12→5 h), and wastewater dilution requirements (20×→16.6×). The enhanced performance was also verified for lignin, humic acid, and fulvic acid. The superior coagulation originated from the synergistic effects of bimetallic coordination, charge neutralization, and sweep flocculation, providing an efficient strategy for aromatic organic pollutant removal.