Combined electrochemical and biological treatment of industrial wastewater using porous electrodes

✍ Scribed by Huu D Doan; Jiangning Wu; Robert Mitzakov

• Publisher: Wiley (John Wiley & Sons)
• Year: 2006
• Tongue: English
• Weight: 348 KB
• Volume: 81
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.1575

✦ Synopsis

Abstract

Zn^2+^, Ni^2+^ and propylene glycol methyl ether were simultaneously removed from simulated wastewater in a column consisting of an aerated packed bed and an electrochemical cell with a porous aluminium foam cathode and a porous stainless steel anode. After 48 h of sole electrochemical treatment at a liquid rate of 0.00183 m^3^ m^−2^ s^−1^, Zn^2+^ and Ni^2+^ were reduced by 95 and 80% respectively. In the turbulent flow regime with liquid rates varied from 0.0137 to 0.0366 m^3^ m^−2^ s^−1^, both Zn^2+^ and Ni^2+^ removal decreased by about 15% rather than increased as expected for a mass transfer‐controlled process. This can be attributed to bubble formation at the cathode surface under turbulent flow, which led to a lower active surface area for the electrodeposition of metal ions. Porous electrodes enhanced the metal removal by 17 and 60% for Zn^2+^ and Ni^2+^ respectively as compared with flat plate electrodes. Using combined biological and electrochemical treatment at a water rate of 0.00183 m^3^ m^−2^ s^−1^ and an air rate of 0.0518 m^3^ m^−2^ s^−1^, 99% of Zn^2+^ and 95% of Ni^2+^ were removed. In addition, the 5 day biological oxygen demand (BOD~5~) was reduced by 58% concurrently over 72 h of treatment. Copyright © 2006 Society of Chemical Industry