Journal of Chemical Technology and Biotechnology, Vol.78, No.6, 632-641, 2003
Treatment of wastewater using a combined biological and electrochemical technique
Simulated wastewater containing propylene glycol methyl ether, Ni2+ and Zn2+ was treated using an aerated packed column. An electrochemical cell was also installed beneath the packing support in the bottom section of the column. The flowrate of water through the column was maintained at 8.94 kg m(-2) s(-1). For 72 h of treatment using aeration alone, the BOD5 was reduced by 43%, 56%, and 54% for air flowrates of 0.00094, 0.00141, and 0.00188 kg m(-2) s(-1) respectively. On the other hand, when the electrochemical cell was activated without aeration, the BOD5 was reduced by 15%, 17%, and 23% at the applied voltages of 8, 16, and 25V respectively. When both aeration of the wastewater and a voltage of 25V were used, the percentage removal of BOD5, on the average, was about 65% for all air flowrates used. The concentrations of Ni2+ and Zn2+ were also reduced by 57% and 61% respectively, in the absence of the supporting electrolyte. The addition of potassium chloride (100 ppm) as the supporting electrolyte enhanced the metal removal by 30%. (C) 2003 Society of Chemical Industry.