In situ growth of ZIF-8 within wood channels for water pollutants removal.

• ZIF-8 is coated on the aligned wood channels to form ZIF-8/wood composites. • The crystallinity and adsorption function of ZIF-8 were well maintained. • The ZIF-8/wood was assembled into a filter system for wastewater purification. • The ZIF-8/wood composites have stable chemical properties and good recyclability. The practical application of ZIF-8 crystals is commonly limited by their powder form. In this work, natural balsa wood sheets were employed as substrate for dispersing and shaping ZIF-8 particles. By in situ growth method, ZIF-8 layer was coated on the aligned wood channels to construct ZIF-8/wood composites with a hierarchical structure. A good affinity and interfacial compatibility between ZIF-8 and wood lumens was observed. The wood channels enable high-speed water transport and the ZIF-8/wood composites were integrated into filtration systems for continuous wastewater treatment. At a 7.9 wt% ZIF-8 loading, the three-layered ZIF-8/wood filter (ZW-2) presented an effective treatable volume of 800 mL of 10 mg L−1 Cu2+ solution. Moreover, ZW-2 exhibited an excellent recyclability and reusability. Such wood-based composite is renewable, low cost, and holds great potential for practical environmental remediation. [ABSTRACT FROM AUTHOR]