Degradation of a textile azo dye using biological treatment followed by photo-Fenton oxidation: Evaluation of toxicity and microbial community structure

•COD and UV absorbance were effectively reduced (>90%).•The final effluent was non-toxic to Artemia salina and Microtox.•DGGE was used to detect bacteria and eukaryotes in the biological process.•Algae were detected for the first time in a reactor treating textile effluent.