Two-step green synthesis of metal organic frameworks-modified cellulose nanofiber for efficient removal of Cu(II) and tetracycline: Experiments, DFT studies, and LCA evaluation.

The coexistence of heavy metals and antibiotics in water bodies poses significant challenges for efficient treatment. This study innovatively utilizes the complementary structure and function of cellulose nanofibers (CNF) and metal-organic frameworks (MOFs), and applies green ultrasound and freeze-drying technology to prepare MOF-CNF composite materials. The results showed that MOF-CNF prepared with a mass ratio of MOF to CNF of 0.2 had the best removal efficiency for tetracycline (TC) and copper (Cu(II)). The adsorption process conforms to the pseudo-second-order kinetic model, Langmuir and Dubinin-Radushkevich isotherms model. Thermodynamic studies indicated that the TC and Cu(II) adsorption was more rapid at a higher temperature. Besides, the coexistence of anions and antibiotics has almost no influence on the adsorption of TC-Cu by MOF-CNF. The electrostatic interaction, hydrogen bonding and complexation were the main mechanisms of TC and Cu(II) adsorption. Furthermore, MOF-CNF composite material demonstrated excellent antibacterial effectiveness. Life Cycle Assessment (LCA) showed that the structural synergy in MOF-CNF composites, reduces overall environmental impact while enhancing sustainability. The MOF-CNF composite material prepared in this study achieved synergistic enhancement of pollutant removal, providing an efficient and sustainable solution for the treatment of heavy metal and antibiotic composite pollutants in water bodies.