DEGRADATION OF REACTIVE BLACK 5 DYE IN WATER FALLING FILM DIELECTRIC BARRIER DISCHARGE REACTOR (DBD)
Abstract
Reactive Black 5 (RB5) is one of the synthetic reactive dyes frequent used in the textile industry, due to its solubility in water and reactive groups which form covalent bonds within the fibre.
The aim of this study was to investigate the degradation of the Reactive Black 5 dye by using an advanced oxidation process in a non-thermal plasma reactor based on water falling film dielectric barrier discharge (DBD).
In the past decades, an increasing number of procedures have been reported to remove pollutants from wastewater. An example of these is what is known as the Advanced Oxidation Processes (AOPs), which are employed for textile wastewater treatment. These (AOPs) are environmentally friendly methods based on chemical, photochemical or photocatalytic production of hydroxyl radical (HO•). This powerful oxidizer can react with most organic compound found in wastewater, such as dyes.
The effects of different initial pH (9, 7 and 5) of the dye solutions on the degradation during subsequent recycling of the Reactive Black 5 dye solution through the DBD reactor. Change of pH values and the effect of pH adjustments of the dye solution after each recycling on colour removal were also tested. It was found that the initial pH of the dye solutions and the pH adjustments of the dye solution after each recycling process did not affect the colour removal.
Decolonization of the Reactive Black 5 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor based on the coaxial water (DBD) film. The initial dye concentration in the solution was 40 mg /L.
The dye solution was recycled through a DBD reactor with an applied energy density of 45-315 kJ/ L. The effect of residence time was studied after 5 minutes and 24 hours of plasma treatment.
Changes in the pH values of the dye solution were tested after each recycling process. The decolourization and degradation effectiveness of high concentration dye Reactive Black 5 (40, 80, 200 and 500 mg/L) was examined. Efficiency degradation and possible degradation pathways were monitored by measuring the COD value.
Experimental results confirmed the effectiveness of the procedure in the Reactive Black 5 degradation. The final degradation products did not cause any significant toxic effects to Artemia salina.
