Abstract
Cobalt Hexacyanoferrate (CoHCF) was tested for the selective uptake of K from seawater and the electrochemical method was adopted for the desorption and regeneration of the material. Powder form CoHCF could adsorb about 6.5 mmol/g of K from the seawater. For the ease of the electrochemical desorption and regeneration, CoHCF thin film was coated onto the Indium Tin Oxide (ITO) glass to obtain a CoHCF electrode. K adsorption kinetics on CoHCF thin film was found to be well fitted with the intraparticle diffusion model, which was a two-step process. Five consecutive adsorption-desorption-regeneration cycles were carried out to know the gradual decrease in the adsorption capacity owing to changes in the redox states of two metals, Co and Fe, in the material. Fourier Transform Infrared Spectroscopy (FT-IR) and Ultraviolet-Visible (UV-Vis) measurement results corresponded to the color change of CoHCF thin film, indicating the valence change of transition metals and the exchange of alkali metal cations happened on the CoHCF at different operation stages. In order to elucidate the reaction mechanism, composition of the material was analysis in the following steps: adsorption, desorption, and regeneration. It was proved that the system based on CoHCF thin film modified electrode had the potential of recovering potassium from seawater.
Highlights
The results demonstrate that the selective recovery of K+ from the seawater can be realized using the highly efficient Metal hexacyanoferrates (MHCF) modified electrodes
The study brought up a new system based on the CoHCF thin film modified electrode, which was proved to be effective in K+ recovery from seawater for at least five cycles
The excellent K+ adsorption ability by CoHCF was demonstrated in seawater
Summary
Together with potash ore mining, secondary sources such as urine, sewage water, and biomass leachate are gradually being used as sustainable potassium resources [4,5,6,7]. Another reliable source of this valuable element can be the brine wasted from the seawater desalination system, which uses a rather new technology—. The increase in salinity of the drained area could be controlled [10], and, the huge element resources can be used [11]. Along with the environmental sustainability, some economic value can be expected [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
