Electrochemical deposition for the separation and recovery of metals using carbon nanotube-enabled filters

Abstract

A carbon-nanotube enabled electrochemical filter was developed to separate and recover metals from mixed metal waste streams.

Electrochemical approaches for selective recovery of critical elements in hydrometallurgical processes of complex feedstocks

“…(C) Schematic diagram of an electrodeposition system using carbon nanotube-based filters for the selective recovery of metals. Reproduced with permission ( O'Connor et al., 2018 ). Copyright 2018, Royal Society of Chemistry, copyright 2018.…”

“…Electrodeposition of REEs has also been investigated using ionic liquids such as ammonium-, pyrrolidinium-, and imidazolium-based electrolytes ( Kurachi et al., 2012 ; Lodermeyer et al, 2006 ; Sanchez-Cupido et al., 2019 ). In aqueous environment, because the electroreduction of rare earths into metallic form is almost impossible, a different kind of electrodeposition—formation of oxide on cathode—was reported for selective recovery of rare earths from mixed metal wastes ( O'Connor et al., 2018 ). In the electrochemical system illustrated in Figure 7 C, REEs were converted to oxides, assisted by OH − ions generated from oxygen reduction or water reduction on the cathode.…”

“…In the electrochemical system illustrated in Figure 7 C, REEs were converted to oxides, assisted by OH − ions generated from oxygen reduction or water reduction on the cathode. When a multicomponent synthetic stream containing Cu and Eu was injected into multiple stages of filters at different operation voltages, selective separation/retention of Cu and Eu was achieved with the recovery of 97% and 65% for Cu and Eu, respectively ( O'Connor et al., 2018 ).…”

“…Ga was prepared in 100 mM NaCl Unaligned carbon nanotubes encapsulated in polyvinyl alcohol filters 86%–96% max recovery (except for As). Metals are recovered as oxides ( O'Connor et al., 2018 ) Redox-active functional electrode Y 0.1 M Y 3+ Aqueous Y 3+ ion imprinted ferricyanide-embedded polypyrrole film / ( Du et al., 2015 ) Electrodialysis/vacuum membrane distillation Ce 0.2 mM Ce 4+ Nitric acid Anion exchange membranes (ASV, QPPO, CJMA-3), vacuum membrane distillation (TJ [the PVDF hollow fiber membrane produced by Tianjin University of Technology], DH [the PVDF hollow fiber membrane produced by Dehong CO., Ltd., China]) 90% recovery efficiency of nitric acid at 0.1 mM for 6 h using CJMA-3 anion exchange membranes, 99.9% of Ce 4+ rejected and concentrated during vacuum distillation ( Ren et al., 2018 ) Electrodialysis Sc 20 ppm, 40 ppm, 80 ppm Sc 3+ 0.1M sulfuric acid as catholyte and anolyte in rinse compartments Anion exchange membrane (PC SA [the anion-exchange membrane obtained from PCCell with strongly alkaline with polyester reinforcement]), cation exchange membrane (PC SK the cation-exchange membrane procured from PCCell with strongly acidic with sulfonic acid functional groups]), both from PCell 99.52% of Sc 3+ removed from 20 ppm solution at 3 V ( Li et al., 2021 ) Electrodialysis Nd, Dy, Tb Anthracite coal ash leached with nitric acid Nitric acid, 0.01 M NaNO 3 Cation exchange membrane (CR67, MKIII, blank, GE Water & Processing Technologies) Tb: 90% extracted, 55% recovered Nd: 80% extracted, 74% recovered Dy: 74% extracted, 62% recovered All at 50 mA ( Couto et al., 2020 ) …”

Preparation of Cu-CNT/ceramic Hollow Fiber Membranes and Investigation of their Antibiofouling Performance under Electrochemical Assistance

“…As electrochemical technology is applied in metal recovery due to friendly environment and low cost [4,5] , introducing electrochemical assistance might be an effective approach to limit biocide loss. At the same time, electrochemical assistance has been reported to prevent microbial adsorption by regulating the interaction between pollutants and membranes through electrostatic repulsion [6,7] .…”