摘要
The simultaneous electro-oxidation of Ni(Ⅱ)-citrate and electrodeposition recovery of nickel metal were attempted in a combined electro-oxidation-electrodeposition reactor with a boron-doped diamond(BDD)anode and a polished titanium cathode.Effects of initial nickel citrate concentration,current density,initial p H,electrode spacing,electrolyte type,and initial electrolyte dosage on electrochemical performance were examined.The efficiencies of Ni(Ⅱ)-citrate removal and nickel metal recovery were determined to be 100%and over 72%,respectively,under the optimized conditions(10 m A/cm^(2),pH 4.09,80 mmol/L Na_(2)SO_(4),initial Ni(Ⅱ)-citrate concentration of 75 mg/L,electrode spacing of 1 cm,and 180 min of electrolysis).Energy consumption increased with increased current density,and the energy consumption was 0.032 kWh/L at a current density of 10 m A/cm^(2)(pH 6.58).The deposits at the cathode were characterized by scanning electron microscopy(SEM),energy-dispersive spectrometry(EDS),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).These characterization results indicated that the purity of metallic nickel in cathodic deposition was over 95%.The electrochemical system exhibited a prospective approach to oxidize metal complexes and recover metallic nickel.
基金
supported by Major Science and Technology Program for Water Pollution Control and Treatment in China(No.2017ZX07202-001-007)
the National Science Fund for Distinguished Young Scholars(No.51625801)
the Guangdong Innovation Team Project for Colleges and Universities(No.2016KCXTD023)
Guangdong Provincial Science and Technology Project(No.2017A020216014)
the National Science Fund,China(No.21777106)
Pearl River S&T Noval Program of Guangzhou,China(No.201710010065)
the key projects of Dongguan social science and technology development plan(No.2019507140204)。
