Stable, regenerable and 3D macroporous Pd (II)-imprinted membranes for efficient treatment of electroplating wastewater

Pd (II) from release-unbridled electroplating wastewater is causing great challenges, which is unfavourable either to human health or resource reutilization. Ion-imprinted membranes (IIMs) have recently drawn attentions for selective separation of specific ions from analogues. In this context, we have developed a facile strategy for fabrication of Pd (II)-imprinted membranes (Pd-IIMs) for the selective separation of Pd (II). The enhanced flux was obtained by three-dimensional macroporous structure on polydimethylsiloxane (PDMS). Then the Pd-IIMs were synthesized by a modification-imprinting strategy based on PDMS substrates. With the existence of Co (II), Cu (II), Cd (II) and Ni (II), the as-obtained Pd-IIMs showed superior adsorptive selectivity (3.32-5.06) and perm-selectivity (2.34-4.04) towards Pd (II), as well as the satisfactory regeneration performance (more than 92% of the initial rebinding capacities after 5 cycles of adsorption/desorption). Moreover, the as-prepared Pd-IIMs also displayed stability on separation factors even under ultrasonic treatment. Notably, the overused Pd-IIMs after applications for selective separation of Pd (II) showed a satisfactory performance for the treatment of methylene blue (99.87%), which displayed potentials for the further applications. The Pd-IIMs and preparation strategy developed in this work have shown a positive opportunity for the efficient treatment of electroplating wastewater and organic dyes.