Bioinspired Metal Binding Interfaces for Continuous Metal Removal from Water

Herein, we introduce a water flow system that combines adhesion with the selective complexation of metal ions from aqueous solutions, enabling the removal of multiple metal ions from polluted water. Specifically, we utilize a bioinspired polymeric system based on l-3,4-dihydroxyphenylalanine (l-DOPA) carrying a terpyridine functionality that efficiently coats stone wool fibers in a continuous flow coating process, enabling the in-line generation of water purification cartridges. We assess the carefully characterized coated fibers for their metal removal capacities in single metal solutions as well as multi-metal solutions to determine binding affinities via inductively coupled plasma mass spectrometry (ICP-MS). The findings of these studies reveal that chromium (Cr), copper (Cu), and lead (Pb) are adsorbed efficiently by the ligand-coated stone wool fibers. Moreover, we investigated the long-term application of the coated fibers, which displayed no saturation for the removal of Cu over 15 column volumes, making the introduced coating system an excellent candidate for applications in urban stormwater management.