EVALUATION OF THE COMBINED GAC-SBR SYSTEM PERFORMANCE IN THE REMOVAL OF YELLOW 3 AND DISPERSE YELLOW 3 REACTIVE DYES FROM THE WASTE

Background and purpose: Chemical dyes used in textile industries involve some potential risks including carcinogenic and mutagenic effects in human. Furthermore, penetration of different dyes into surface and groundwater is a source of color in water reservoirs. This study aims at investigating the removal efficiency of yellow 3 and disperse yellow 3 reactive dyes by combined CAC-SBR system. Materials and methods: This experimental study was conducted on a batch scale and two SBR reactors were used. Wastewater samples used in this study were synthetic (COD=1800). After setting up the reactors, yellow 3 and disperse yellow 3 reactive dyes were injected to the system and its removal efficiency was investigated during different reaction times. After determining the SBR system efficiency in dye and COD removal, GAC-SBR system efficiency was examined. Results: During 24 hours of reactions, the efficiency of SBR and GAC-SBR systems in the removal of reactive yellow3 dye was 58% and 72%, while for disperse yellow 3 it was 85 and 91%, respectively. Also, during 14 hours of reaction, the efficiency of SBR and GAC-SBR systems for COD removal was 98 and 98.5%, respectively. Conclusion: The efficiency of GAC-SBR system in the removal of reactive yellow 3 and disperse yellow 3 dyes was higher than that of the SBR system. However, their difference was insignificant regarding the COD removal. Overall, increase in the reaction time led to increase in the efficiency of systems and in a specific time of the reaction, their removal efficiency became uniform.