Coupling of acrylic dyeing wastewater treatment by heterogeneous Fenton oxidation in a continuous stirred tank reactor with biological degradation in a sequential batch reactor

• Published in: Journal of environmental management 2016-01, Vol.166, p.193-203
• Main Authors: Esteves, Bruno M., Rodrigues, Carmen S.D., Boaventura, Rui A.R., Maldonado-Hódar, F.J., Madeira, Luís M.
• Format: Article
• Language: English
• Subjects: Biodegradation; Biodegradation, Environmental; Biological degradation; Bioreactors; Coloring Agents - chemistry; Coloring Agents - metabolism; Continuous stirred tank reactor; Dyes; Heterogeneous Fenton oxidation; Hydrogen Peroxide - chemistry; Iron; Oxidation; Oxidation-Reduction; Textile dyeing wastewater; Toxicity; Vibrio fischeri; Waste Water - chemistry; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - metabolism; Water treatment; Zeolites - chemistry
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2015.10.008

This work deals with the treatment of a recalcitrant effluent, from the dyeing stage of acrylic fibres, by combination of the heterogeneous Fenton's process in a continuous stirred tank reactor (CSTR) with biological degradation in a sequential batch reactor (SBR). Three different catalysts (a commercial Fe/ZSM-5 zeolite and two distinct Fe-containing activated carbons – ACs – prepared by wet impregnation of iron acetate and iron nitrate) were employed on the Fenton's process, and afterwards a parametric study was carried out to determine the effect of the main operating conditions, namely the hydrogen peroxide feed concentration, temperature and contact time. Under the best operating conditions found, using the activated carbon impregnated with iron nitrate, 62.7% of discolouration and 39.9% of total organic carbon (TOC) reduction were achieved, at steady-state. Furthermore, a considerable increase in the effluent's biodegradability was attained (BOD5:COD ratio increased from