Iranian Association of Environmental Health (IAEH)
Abstract
This study investigates the anaerobic treatability of reactive Red2 in
an anaerobic/aerobic sequential process. Laboratory scale anaerobic
baffled reactor and fixed activated sludge reactor were operated at
different organic loadings and hydraulic retention times. The effects
of shock dye concentration on the chemical oxygen demand and color
removal efficiencies were investigated in the anaerobic baffled
reactor. The effect of hydraulic retention time on the color and
chemical oxygen demand removal efficiencies were also investigated in
the aerobic reactor. The studies were carried out in continuous mode
and the effluent of the anaerobic baffled reactor was used as feed for
the fixed activated sludge reactor. Chemical oxygen demand removal
efficiency of 54.5% was obtained at HRT =1 day in the anaerobic
reactor. The average color removal was 89.5%. Chemical oxygen demand
removal efficiency of 69% was obtained at HRT =7 h in the aerobic fixed
activated sludge reactor. A slight decrease of the color was also
observed in the aerobic reactor. This investigation has shown that
successful treatment of a highly colored wastewater is possible in the
anaerobic baffled reactor. Also the results showed that, anaerobic
biological system has higher efficiency in dye removal than fixed
activated sludge system, while aerobic system has higher efficiency in
chemical oxygen demand removal comparing with the anaerobic baffled
reactor