Ozone and Electrocoagulation Processes for Treatment of Dye in Leather Industry Wastewater: A Comparative Study

The aim of this study was to investigate the feasibility of two decontaminating processes, ozonation and electrocoagulation, to decolorize wastewater generated by humid finishing leather production. With the objective to determine if one or both process could remove color, benchscale experiments were conducted with three different colorants, representative of the main dye groups: di-azo (CI Direct Blue 1), anthraquinone (CI Green G) and aniline (CI Fast Red B base). Two methods were compared on the basis of electrical energy consumption. This study revealed that for two of the three studied colorants, CI Direct Blue 1 and CI Fast Red B base, electrocoagulation achieved better removal, closely 99% of decolorization in each case. Nonetheless on the case of the third dye, CI Green G, ozonation achieved higher decolorization, up to 89%. Keywords—Electrocoagulation, decolorization, leather industries, ozone, wastewater.