Removal of color and COD from textile wastewater using a combination of AOPS/UV and coagulation pre-treatment

Abstract

In this study, COD and color in textile dyeing wastewater were treated with the Ultraviolet-based Advanced Oxidation Processes (AOPs/UV) combined with a coagulation pretreatment. The results showed that the primary coagulation treatment can remove 49% COD (432 mg/L) and 50% color (465 Pt-Co). The secondary treatment by the AOPs/UV using ozone (O₃₎ as oxidizing agent was found to be the most effective with removal efficiency COD and color were 96% (32 mg/L) and 95% (45 Pt-Co), respectively which can meet the highest discharge standards of current textile dyeing industry wastewater. While the AOPs/UV using S₂O₈^2- and H₂O₂ as oxidizing agents showed the COD removal efficiencies were 84% (134 mg/L) and 75% (214 mg/L) as well as the decolorization efficiencies were 75% (214 mg/L) and 85% (127 Pt-Co), respectively. These findings can be expected as technological orientation for design of treatment systems using different approaches from traditional ones such as microbiological and physico-chemical treatment systems. The AOPs/UV solution combined with coagulation pretreatment, therefore, can be an effective method applied to treat the COD and decolorization in the textile dyeing wastewater.