However, this material lacks functional groups such as -N-H, -O-H, and -COOH that facilitate the binding to metal ions; hence, adsorption can occur via either ion exchange or intraparticle diffusion . The adsorption of metal ions using ZIF-8 as an adsorbent can be further improved via conjugation with other nanomaterials, for instance, graphene oxide (GO) . Removal of Cu 2+ ions may occur via the coordination to the functional groups of GO without any observation of ion exchange with the Zn nodes of ZIF-8 crystals . TOCNF and CP improved the metal ion adsorption compared to other materials (Figure , Table ). The preparation methods presented herein are fast and straightforward without needing a solvothermal procedure that requires a long reaction time (24 h) and high temperature (Table ) . A drawback of using ZIF sorbents in powder form is their tedious separation after the adsorption process. Thus, ZIF-8 was modified with magnetic nanoparticles to make their separation easier . The use of our CelloZIFPaper allows the simple separation of the adsorbent without the need for any extra steps (Table ). In a recent study, ZIF-8 nanoparticles were in-situ grown onto electrospun polyacrylonitrile (PAN) nanofibers membrane (ZIF-8/PAN NF) via hot pressing . ZIF-8 crystals were also produced on an alumina hollow fiber membrane via the in-situ solvothermal method and the layer-by-layer method (Table ) . This membrane fabrication method requires silanization of alumina with 2% of 3-(aminopropyl)triethoxysilane (APTES) solution using toluene which is toxic and harmful to the environment (Table ) . In contrast, the membrane preparation methods proposed in our study are entirely water-mediated, rendering them simpler and more environmentally friendly than the one mentioned earlier. Additionally, the CelloZIFPaper exhibited higher adsorption capacity toward heavy metal ions than several other adsorbents (Table ).