The study is aimed at improving a methodology to purify nickel or cobalt ion containing effluents by an electrochemical filter. Consequently, a cell with reticulated vitreous carbon (RVC) cathode for Ni and Co depletion was designed to analyze, at room temperature and pH equal to 6, flowrates and cathodic potentials able to affect the electrochemical process. Starting with Ni and Co initial concentration of 150ppm, it is possible to reach a concentration lower than 0.1ppm for both metals in less than 1h, with a flowrate of about 1300ml/min and for a catholyte volume of 1000ml, under mass transport control conditions (for Ni −1.1V and for Co −1.2V cathodic potential versus Standard Calomel Electrode (SCE)). Moreover, the proposed work studied the process kinetics and fluid dynamics through the use of dimensionless relations such as Reynolds and Sherwood numbers. In addition considerations on current efficiency for reduction of both metal ions were done. •Purification of effluents by electrowinning of nickel or cobalt ion•Characterization of the metal deposition on reticulated vitreous carbon•Dimensionless analysis for each ionic species electrodeposited•Efficiency analysis and cost estimation of a scale-up of the electrochemical system