Treatment of Dye Wastewater by Continuous Iron-Carbon Microelectrolysis

Treatment of dye wastewater with a chemical oxygen demand (COD) of 1000-1600mg/L was studied by the use of a continuous iron-carbon microelectrolysis process (MEP) and a continuous iron-carbon microelectrolysis-upflow anaerobic sludge blanket (UASB)-sequential batch reactor (SBR) process (MEUSP). Results indicated, first, that high-temperature processing to generate a microporous MEM can effectively prevent caking of MEM. MEP displayed good performance in treatment of the wastewater, with a color removal of 75% and COD removal of more than 60% when the hydraulic retention time (HRT) and flocculation pH were set at 6 and 11h, respectively. Effluent reflux technology can effectively reduce the amount of alkali used in the process. MEP can be effectively combined with a UASB by optimization of the HRT (10h), at which time the flocculation pH is 8, which matches the influent pH of the UASB. COD of the final effluent from the MEUSP was kept in the range of 70-98mg/L.