Treatment of dye wastewater containing acid orange II using a cell with three-phase three-dimensional electrode

The removal of color and chemical oxygen demand (COD) from simulated dye wa stewater containing Acid Orange II was experimentally investigated using co agulation-electrooxidation. Two kinds of coagulation methods, ferrous-media ted coagulation and electrocoagulation were tested as pretreatment. The ele ctrooxidation was carried out in a cell with a three-phase three-dimensiona l electrode using granular activated carbon as particle electrodes. Particu lar attention was paid to probe the effect of cell voltage, airflow rate, s olution conductivity and treatment time on the electrochemical treatment ef ficiency. The experimental results showed that the coagulation-electrooxida tion process could efficiently remove the color and the COD from the simula ted dye wastewater. The overall COD and color removal efficiencies reached as high as 99% and 87%, respectively, by ferrous coagulation (molar rate of Fe(II)/dye: 0.5) and 30-min electrolysis (cell voltage: 20.0V and airflow: 0.1 m(3)h(-1)). (C) 2001 Elsevier Science Ltd. All rights reserved.