Hydraulic retention time influence on azo dye and sulfate removal during the sequential anaerobic-aerobic treatment of real textile wastewater

• Published in: Water science and technology 2017-12, Vol.76 (11-12), p.3319-3327
• Main Authors: Amaral, F M, Florêncio, L, Kato, M T, Santa-Cruz, P A, Gavazza, S
• Format: Article
• Language: English
• Subjects: Aerobic treatment; Aerobiosis; Amines; Anaerobic conditions; Anaerobic treatment; Anaerobiosis; Anoxic conditions; Aromatic compounds; Azo Compounds - chemistry; Azo Compounds - metabolism; Azo dyes; Biodegradation; Bioreactors; Biotechnology; Carcinogens; Chemical compounds; Chemical oxygen demand; Coloring Agents - chemistry; Coloring Agents - metabolism; Colour; Dyes; Effluents; Hazardous materials; Hydraulic retention time; Industrial Waste; Organic matter; Reactors; Removal; Retention; Retention time; Salinity; Sulfate reduction; Sulfates; Sulfates - chemistry; Sulfates - metabolism; Sulfur Oxides; Textile Industry; Textile industry wastewaters; Waste Disposal, Fluid; Waste Water - chemistry; Wastewater; Wastewater treatment; Water treatment
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2017.378

In the present study, we evaluate the behavior of real textile wastewater treatment using a system composed of two sequential pilot-scale reactors (anaerobic followed by aerobic) during 622 days. The work focused on the competition between color and sulfate removal processes, when the hydraulic retention time (HRT) was increased in the anaerobic/aerobic reactors from 16/12 hours in phase I (PI) to 4/3 days in phase II (PII). The organic matter was successfully removed in both phases through the system, and the highest efficiency (75%) was achieved in PII. The increase in the HRT did not improve azo dye degradation under anaerobic conditions. Instead, it favored sulfate reduction, which removal efficiency increased from 26% in PI to 75% in PII. Aromatic amines were detected in the anaerobic reactor effluent and removed in the aerobic reactor.