e Hosseini Koupaie - Civil and Environmental Engineering Department, Amirkabir University of Technology AUT
M. R. Alavi Moghaddam - Civil and Environmental Engineering Department, Amirkabir University of Technology (AUT
S.H Hashemi

The aim of present research was to investigate the performance of anaerobic sequencing batch reactor (An-SBR) for treatment of wastewater containing azo dye Acid Red 18 with the main focus on decolorization kinetic study. Three An-SBRs were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The kinetic study showed that the AR18 decolorization in the reactor with 100 mg/L initial dye concentration followed first order kinetics with respect to the dye concentration. However, in the case of two other reactors with 500 and 1000 mg/L initial dye concentration, correlation of the dye decolorization data suggested two successive parts with two different reaction orders (zero and first order). The results of the UV-Vis analysis as well as the bio-sorption test proved that the AR18 decolorization was mainly due to the anaerobic azo bond reduction and contribution of physical absorption in AR18 decolorization was less than 10%.

Performance, Decolorization, Anaerobic sequencing batch reactor, Azo dye, Kinetic