Abstract
In this experiment, a combined electrooxidation-electrodeposition (EO-ED) system using RuO2/Ti anode and stainless steel cathode was employed to treat nickel-ammonia complexes wastewater, which simultaneously achieved the decomplexation of nickel-ammonia complexes and recovery of nickel metal. Effects of current density, pH value and reaction temperature on electrochemical performance were analyzed. When the current density was 32mA/cm2, pH was 9.0 and the temperature was 60°C, the nickel recovery percentage was 99% and the ammonia removal efficiency was 70%. Combined with the SEM-EDX, XRD and XPS analysis for the cathode surface, it was confirmed that the generation of deposition on the cathode surface was zero-valent nickel. Firstly, Nickel-ammonia complexes were destroyed by electrooxidation process, generating Ni2+ ions and free NH3. Then, Ni2+ ions were reduced onto the cathode and free NH3 were further oxidized. Stability of the system for nickel-ammonia complexes treatment was examined by repeated experiments for fifteen successive cycles. The electrochemical system exhibited a satisfactory stability for nickel recovery and ammonia removal, achieving nickel recovery percentage of 85–95% and ammonia removal efficiency of 65–70%, respectively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.