Testing the advanced oxidation processes on the degradation of Direct Blue 86 dye in wastewater

Abstract

This work tests the viability of applying ozone (O3) and O3 combined with ultraviolet (UV) to degrade the content of synthetic wastewater containing Direct Blue 86 (DB-86) dye. The tested parameters, which included pH, initial concentration of DB-86 dye and time of reaction, were tested in a batch reactor to achieve optimum operating circumstances. The results obtained in this study showed that pH and initial concentration of DB-86 dye controlled the efficiency of the decolorization process. The maximum decolorization was obtained at pH 11. More than 98% of color removal was reported after 35min of O3 treatment (for 100ppm dye concentration). Kinetic analyses showed that color removal of DB-86 dye followed first-order kinetics. The rate of color removal was primarily relative to the initial DB-86 dye concentration. The effect of seawater on the efficiency of the process was studied. Gas Chromatography Mass Spectrum analysis of treated synthetic DB-86 dye solution was performed at the end of the pre-treatment time to study the final degradation products of DB-86 dye. The obtained results revealed that ozonation processes had reduced the zooplankton toxicity belonging to the raw solution and had improved the biodegradability of the DB-86 dye wastewater.