High Throughput Metal Trap: Sulfhydryl-Functionalized Wood Membrane Stacks for Rapid and Highly Efficient Heavy Metal Ions Removal.

Heavy metal pollution is a severe problem worldwide. Great efforts have been devoted to developing effective and eco-friendly ways to remove heavy metal ions from contaminated water. However, challenges remain in terms of the high cost, the complex preparation processes required, low efficiency, and difficulties in scaling-up. Here we report a sulfhydryl-functionalized wood (SH-wood) membrane featuring three-dimensional mesoporous and low-tortuosity lumens, which serve as multi-site metal traps to achieve highly efficient heavy metal ions removal from wastewater. Benefiting from the unique micro-structure of wood, the resulting membrane exhibits a high saturation uptake capacity of 169.5, 384.1, 593.9, and 710.0 mg•g-1 for Cu2+, Pb2+, Cd2+, and Hg2+ ions, respectively. Meanwhile, the SH-wood membrane can be easily regenerated at least 8 times without apparent performance loss. Furthermore, a stacking multi-layers of the SH-wood filter is designed. Due to its high yet universal heavy metal ions absorbance capability, the multi-layer SH-wood filter can effectively remove diverse heavy metal ions from real contaminated water, meeting the WHO standards while also displaying a high flux rate of 1.3×103 L∙m-2∙h-1. Our work presents a promising strategy for the scalable and highly efficient removal of heavy metal ions from sewage for environmental remediation.