Polishing of treated textile effluent using combined electrochemical oxidation and ozonation technique

Textile effluents are known to be complex matrices, requiring a combination of treatment techniques to achieve conditions that allow effluent to be discarded into environment. The electrocoagulation technique manages to remove most of the pollutants present in textile effluents, but generally does not achieve complete removal. This work studied the efficiency of combined electrochemical oxidation and ozonation techniques in the post-treatment of a real textile effluent after electrocoagulation and decantation processes. The experiments were carried out in batch mode using Ti/RuO2electrodes (2 plates) and an ozone generator (0.875 g·h–1·L–1). Three current densities were studied, 33.3, 66.6, and 133.3 A·m–2. The turbidity, color, dissolved organic carbon, and pH were analyzed to evaluate the treatment process. The results showed higher efficiency for removing color and dissolved organic carbon with increasing current density. Applying the ozonation process alone had the lowest color and dissolved organic carbon removal efficiencies. The best experiment was with the current density of 66.6 A·m–2integrated with O3promoted removal percentages of 91.77%, 33.02%, and 91.09% for turbidity, dissolved organic carbon, and color, respectively.