Removal of Color and Chemical Oxygen Demand Using a Coupled Coagulation-Electrocoagulation-Ozone Treatment of Industrial Wastewater that Contains Offset Printing Dyes

• DOI: 10.29356/jmcs.v58i3.146
• Publication Date: 2018-04-24T19:17:21Z
• Authors: Gabriela Roa-Morales; Carlos Barrera-Díaz; Patricia Balderas...; Francisco Zaldumb...; Horacio Reyes Perez; Bryan Bilyeu
• Keywords: Coagulation; Dye; Ozonation; AHC; Electrocoagulation; Química; 01 natural sciences; 6. Clean water; 0104 chemical sciences

Industrial offset printing processes generate wastewater with highly colored obtaining values of 5x106 Pt-Co units and great values of chemical oxygen demand (COD) 5.3x10-5 mg L-1. Thus, conventional technologies such as biologicals treatment fail in reaching the discharge limits. In this research, a sequential treatment was applied: coagulation with aluminum hydroxychloride (AHC), electrocoagulation with Al anodes and finally ozonation. Optimal conditions are found when adding 20 mg L-1 AHC, followed by electrocoagulation at 4 A for 50 min, and finally alkaline ozonation for 15 min, resulting in an overall color removal of 99.99% color and 99.35% COD.