Electrochemical treatment of heavy metals (Cu2+, Cr6+, Ni2+) from industrial effluent and modeling of copper reduction.
An electrochemical technique was tested in a laboratory scale to treat heavy metals (Cu2+, Cr6+ and Ni2+) from plating industrial effluent. The experiments were performed in a membrane reactor having a capacity of 1 l. Stainless-steel sheets with surface area of 0.011 m2 and titanium coated with ruthenium oxide were used as cathode and anode, respectively. The electrolyte was circulated at a constant flow rate (0.42 l/min) and the pH was kept constant at 1. Applied current densities were 10 and 90 A/m2. According to the experiment, it was found that a membrane reactor with plane electrode was capable for treating plating wastewater with low energy consumption (42.30 kWh/kg metal) and low operating cost (5.43 US dollars/m3). More than 99% of metal reduction was achieved and the final concentrations of copper, chromium and nickel in treated water were 0.10-0.13, 0.19-0.20 and 0.05-0.13 ppm, respectively. The brightener had no effect on copper reduction whereas hexavalent chromium had strong effect. The kinetic of copper reduction in the presence of hexavalent chromium was modeled as a two-step process with respect to copper concentration.
Hunsom
M
M
Department of Chemical Technology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Pruksathorn
K
K
Damronglerd
S
S
Vergnes
H
H
Duverneuil
P
P
D002412:Cations; D002857:Chromium / Q000302:isolation & purification*; D003300:Copper / Q000302:isolation & purification*; D004563:Electrochemistry; D007220:Industrial Waste; D019216:Metals, Heavy / Q000302:isolation & purification*; D009532:Nickel / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D013997:Time Factors; D018508:Water Purification / Q000379:methods*
D002412:Cations; D007220:Industrial Waste; D019216:Metals, Heavy; D002857:Chromium; C074702:chromium hexavalent ion; D003300:Copper; D009532:Nickel