Fernando F. Rivera

COPPER REMOVAL FROM AN EFFLUENT GENERATED BY A PLASTICS CHROMIUM‐PLATING INDUSTRY USING A ROTATING CYLINDER ELECTRODE (RCE) REACTOR

Abstract This work shows the application of a rotating cylinder electrode (RCE) in the removal of Cu(II) content from an effluent generated by a plastics chromium‐plating industry, on the laboratory scale; in particular, it deals with rinse water from the electrolytic copper process. This process was designed to convert cupric ions in solution to metal powder. The generation of metal powders in the RCE was achieved at Reynolds numbers between 52925 and 83183 and limiting current densities (JL) in the range of 17 to 25 mA cm−2. The removal of Cu(II) (initially 922 ppm) reached 43 ppm in 10 minutes of electrolysis for Re = 83183 and J = 25 mA cm−2, with a space‐time yield of 88 mg Cu(II) L−1 min−1, 95% current efficiency, and energy consumption of 5.3 KWh m−3. The electrochemical treatment applied to waste rinse water at the RCE allows this treated water to be recycled back to the same rinsing process, avoiding additional consumption and discharge of this liquid.

Parametric Mathematical Modelling of Cristal Violet Dye Electrochemical Oxidation Using a Flow Electrochemical Reactor with BDD and DSA Anodes in Sulfate Media

Abstract An important issue in electrochemical oxidations of pollutant compounds, like organic dyes, is identifying a suitable correlation between operational conditions and electrochemical process performance. In such sense, this work deals with the parametric modelling of direct electrochemical incineration of crystal violet (CV) dye in a FM01-LC flow electrochemical reactor with a plastic spacer configuration using boron doped diamond (BDD) and dimensionally stable (IrO2 and IrO2-SnO2-Sb2O5) anode plates. Mathematical model takes into account the fluid dynamics effects by the use of FM01-LC reactor considering mass transport rate of organic compound (R) from bulk solution to electrode surface, characterized by a dispersion coefficient and Pe number. The effect of strong oxidants produced in the electrode surface can be neglected since the characteristic time constant reaction of pollutants with such oxidants is lower than those describing the diffusion of organic compound to the electrode surface. Model parameters were estimated throughout a fitting method of the experimental data. The model proposed here predicted a 99.7 removal percentage of CV with boron doped diamond and IrO2-SnO2-Sb2O5 anodes obtained experimentally, meanwhile a 79 % removal with the IrO2 anode was reached at Re = 2204 during an electrolysis time of 7200 s for both cases. In the case of IrO2 anodes, complex interactions between hydroxyl-radical and electrode surface provokes an intermediate kinetic process, with an effectiveness factor of 0.59. When BDD and IrO2-SnO2-Sb2O5 anodes were used, the removal process mediated by hydroxyl-radicals absorbed in electrode surface was fully limited by mass transport.