Ion-exchange membranes have been widely used in the separation of ionic mixtures or as a barrier in some types of chemical power source because of their selectivity to cations and anions. In this article, a novel single-ion selective ionexchange membrane was fabricated to selectively separate copper ion from aqueous media. Polyethylenemine (PEI) was deposited onto a commercial cation-exchange membrane through an electric-field-enhanced procedure, and was subsequently modified with an ion imprinting technique. The effects of different parameters such as current density and feed composition on the deposition of PEI were studied. The copper ion imprinted membrane (Cu-IIM) showed lower resistance than the nonimprinted membrane (NIM) indicating the formation of a specific transportation path for the ions. The difference of binding isotherms for copper ion and zinc ion confirmed that the Cu-IIM had specificity to recognize copper ions. The permselectivity of the Cu-IIM was tested on an electrodialysis setup. The imprinting factor calculated from the separation factors of the imprinted and nonimprinted membrane was 1.99, demonstrating that the imprinting process enhanced the permselectivity of the membrane. The transport mechanism of ions in the Cu-IIM was also studied and analyzed.

Graphene oxide (GO) composite membranes were fabricated via layer-by-layer (LBL) assembling poly(ethylenimine) (PEI) and a mixture of GO and poly(acrylic acid) (PAA) on a poly(acrylonitrile) (PAN) support membrane. The composite membranes and their application performance were characterized and evaluated. The X-ray powder diffraction (XRD) spectrum shows that GO was successfully synthesized by the modified Hummers method, and it was homogenously dispersed in the composite membranes. Scanning electron microscopy (SEM) shows the successful assembly of multiple polyelectrolyte PEI and a mixture of GO and PAA bilayers on the PAN support membrane. The ultraviolet-visible (UV-Vis) spectrum indicates that the uniformity and continuity of the composite membrane were enhanced with the increasing number of assembled layers. The hydrophilic and selectivity tests reveals that the addition of GO decreased the water contact angle and enhanced the selectivity for monovalent cations of the multilayer polyelectrolyte composite membranes. All these advantages combine to fabricate a high-flux, high selectivity, and anti-fouling composite membrane for separation applications and water softening.

The concept of flagship species is widely used in conservation biology. Flagship birds play a key role in raising conservation funds, increasing awareness of biodiversity conservation, and maintaining ecosystem services. This study selected flagship bird species in Lishui, Zhejiang Province, China, and assessed their conservation effectiveness and ability to serve as umbrella species. A regional bird survey program from 2019–2022 recorded 361 bird species in Lishui. This study constructed a framework of flagship species selection based on social, ecological, economic, and cultural criteria. The analytic hierarchy process-entropy weight method (AHP-EM) was used to rank the score of 361 bird species, and the MaxEnt model was used to analyze the suitable distribution areas of these species. Finally, 10 species, which covered the distribution sites of all 361 bird species, were selected as the flagship species of Lishui. The distribution areas covered all the nature reserves and the priority areas of biodiversity of Lishui, in which these 10 species can also serve as umbrella species to protect local biodiversity. The methodology and ideas in this study could provide insights into the application of conservation concepts at the local level, as well as suggest possible recommendations for local governments to select flagship species for conservation.