Electrolytic removal of metals using a flow-through cell with a reticulated vitreous carbon cathode

Abstract

O objetivo do presente trabalho foi estabelecer um processo eletrolítico para remover metais de efluentes aquosos usando um catodo tridimensional de carbono vítreo reticulado. Durante o desenvolvimento do trabalho foi estudado a influência do fluxo do eletrólito e da porosidade do eletrodo. A célula eletrolítica utilizou potenciais tais que a reação de redução ocorreu sob controle de transporte de massa. A célula demonstrou eficiência na remoção de chumbo, zinco e cobre, reduzindo a concentração desses metais de 50 mg.L -1 a 0,1 mg.L -1 em 20 min de recirculação da solução.The aim of the present study was to establish an electrolytic method for the removal of metals from wastewater using a three dimensional, reticulated vitreous carbon cathode. During the development of the experimental set up, particular attention was paid to the electrolyte flow rate and to the cathode porosity. The electrolytic cell employed potential values in such a way that the metals reduction reaction occurred under mass transport control. These potentials were determined by hydrodynamic voltammetry on a vitreous carbon rotating disc electrode. The cell proved to be efficient in removing copper, zinc and lead and it was able to reduce the levels of these metals from 50 mg/L to 0.1 mg/L.

Determination of Nitrites in Water by In-electrode Coulometric Titration in Reticulated Vitreous Carbon Electrode

“…for metal removal in waste water treatment [19][20][21] or electrochemical pre-concentration for atomic spectroscopy. 22 Obviously, the electrochemical properties such as electrochemical signal to background ratio are of no significance here.…”

Mass Transfer to Amalgamated Copper Rotating Disk Electrode

“…8-10.The data were fitted to obtain the following correlation applied for different initial zinc concentrations: (5) For 13067 < Re < 57552 and 550 < Sc < 1390 with correlation coefficient (CR) equal to 0.98.…”

“…[3][4][5][6][7][8][9] Other researchers calculate the diffusion coefficient of metallic ions in a dilute solutions under the conditions of their experiments using Levich equation. 3,6,8,10) The measurements of mass transfer coefficients to rotating disc electrode have been investigated by several researchers using different electrode materials and reactions systems under laminar, transient and turbulent flows.…”

Galvanostatic removal of Pb2+ ions from diluted solutions by the use of a membrane-less flow-through cell with stainless steel wool electrodes

“…It is clear from equation 7, that Q has no significant influence on X Pb 2+ (see also Figure 3a), although several other studies showed that the rate of electrochemical reactions under mass transport conditions is dependent on Q. 2,3,6,12 According to Koene and Janssen, 32 increases in Q enhance the electrochemical-reaction rate as a consequence of the diffuse layer becoming thinner. In the present case, lower Q values possibly promoted insignificant changes in the mass transport coefficient, while higher ones led to the formation of preferential streaming channels and/or dead zones.…”

“…Electrochemical techniques have been extensively used for the treatment of aqueous effluents because they offer an environmentally and friendly way of removing toxic metallic ions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and/or organic species [16][17][18][19][20][21][22] via redox reactions. The environmental compatibility is the main advantage of electrochemical methods, as the reagent, the electron, is a "clean reagent".…”