Journal of Chemical Technology and Biotechnology, Vol.76, No.11, 1124-1131, 2001
Electrochemical oxidation of tannery wastewater
Tannery wastewater was treated by an electrochemical oxidation method using Ti/Pt, Ti/PbO2 and Ti/MnO2 anodes and a Ti cathode in a two-electrode stirred batch reactor. The changes in colour concentration, chemical oxygen demand (COD), ammonia (NH4+), sulfide and total chromium have been determined as a function of treatment time and applied current density. Gas chromatography mass spectrometry (GC-MS) analysis, performed on the wastewater samples before and after treatment, as well as on foam samples, is reported. Anode efficiency, rate constants and energy consumption were estimated and discussed. The efficiency of Ti/Pt was 0.802 kgCOD h(-1)A(-1)m(-2) and 0.270 kgNH(4)(+) h(-1)A(-1)m(-2), and the energy consumption was 5.77kWhkg(-1) COD and 16.63kWhkg(-1) of NH4+. The order of efficiency of anodes was found to be Ti/Pt much greater than Ti/PbO2 > Ti/MnO2. The results indicate that the electro-oxidation method could be used for effective oxidation of tannery wastewater and a final effluent with substantially reduced pollution load can be obtained.