A sequential anaerobic-aerobic treatment process based on mixed culture of
bacteria isolated from textile dye effluent-contaminated soil was used to d
egrade sulfonated azo dyes Orange G (OG), Amido black 10B (AB), Direct red
4BS (DR) and Congo red (CR). Under anaerobic conditions in a fixed-bed colu
mn using glucose as co-substrate, the azo dyes were reduced and amines were
released by the bacterial biomass. The amines were completely mineralized
in a subsequent aerobic treatment using the same isolates. The maximum degr
adation rate observed in the treatment system for OG was 60.9 mg/l per day
(16.99 mg/g glucose utilized), for AB 571.3 mg/l per day (14.46 mg/g glucos
e utilized), for DR 112.5 mg/l per day (32.02 mg/g glucose utilized) and fo
r CR 134.9 mg/l per day (38.9 mg/g glucose utilized).