Vol.:(0123456789) 1 3 Environmental Sustainability (2019) 2:145–155 https://doi.org/10.1007/s42398-019-00057-1 ORIGINAL ARTICLE Application of a downfow microaerophilic fxed flm (DFMFF) reactor for the treatment of dye house efuents using a developed bacterial consortium Darshna K. Patel 1  · Devayani R. Tipre 1  · Shailesh R. Dave 2 Received: 1 October 2018 / Revised: 10 April 2019 / Accepted: 7 May 2019 / Published online: 20 May 2019 © Society for Environmental Sustainability 2019 Abstract The present study describes a downfow microaerophilic fxed flm (DFMFF) reactor based treatment of dye house efu- ents. The major characteristics of the two efuents E-2 and E-5 under study were; chemical oxygen demand (COD) 4680- 16,266 mg L −1 , biological oxygen demand (BOD) 1575–3151 mg L −1 and American Dye Manufacturers’ Institute (ADMI) color index of 10,794–21,413. DFMFF reactor was packed with ultra-high molecular weight polyethylene (UHMWPE) shredding. The developed consortium was allowed to grow and form bio-flm on packed UHMWPE. Degradation of the efuents at a various hydraulic retention time (HRT) and organic loading rate (OLR) was studied. Batch mode studies in the reactor showed > 80% removal of BOD and COD at OLR of 4.3 kg L −1  day −1 of E-2 and 2.4 kg L −1  day −1 of E-5 at 48 h HRT. Fourier Transform Infrared Spectroscopy (FTIR) and High Performance Liquid Chromatography (HPLC) analysis confrmed biodegradation and obtained results indicated signifcant induction of oxidoreductive enzyme activities of azore- ductase, NADH–DCIP reductase and laccase enzymes. Reduction in phytotoxicity and microbial toxicity was observed after the treatment of both the efuents. The reactor was also operated on continuous mode for treatment of E-2 under sequential anaerobic–aerobic phase and charcoal treatment. Results of sequential efuent treatment resulted in a reduction of > 99% of COD, BOD and ADMI along with > 88% of solids removal from the efuent. The resulting efuent was clear and meets the discharge criteria so as to release into the sewers. Keywords Dye house efuent · Downfow microaerophilic fxed flm reactor · Consortium · Degradation · Oxidoreductive enzymes Introduction Dye-containing wastewater is one of the most concerned wastes as they pollute the area where they are discharged by increasing their toxic efects on the living beings in the vicinity (Venkata Mohan et al. 2004; Katuri et al. 2009; Kurade et al. 2019). Moreover, the dense coloured waste- waters from dye manufacturing industries need more con- cern as the number of toxic chemicals and colour is very high. Use of various wastewater treatment agents such as UV, H 2 O 2 , ozone, along with conventional physicochemi- cal treatment methods have not proved efective for the treatment of coloured wastewaters due to their high operat- ing costs and generation of huge amount of sludge (Davies et al. 2005; Frijtersa et al. 2006). Therefore, bioremedia- tion is an attractive option which ofers an eco-friendly treatment alternative for the development of sustainable treatment technology (Pandey et al. 2007). Most of the bioremediation studies are reported with pure cultures, but large scale work may not be possible with this method as a large amount of efuent cannot be sterilized and in the reactor it is not economical to maintain the aseptic condi- tions. Instead, the use of consortium based system can Electronic supplementary material The online version of this article (https://doi.org/10.1007/s42398-019-00057-1) contains supplementary material, which is available to authorized users. * Shailesh R. Dave shaileshrdave@yahoo.co.in; srdave@gujaratuniversity.ac.in 1 Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad, Gujarat 380009, India 2 Xavier’s Research Foundation, Loyola Centre for Research and Development, St. Xavier College Campus, Ahmedabad, Gujarat 380009, India