Enhanced decolorization of dyeing wastewater in a sponges-submerged anaerobic reactor

摘要

This study was conducted to assess the potential of a sponges-submerged anaerobic baffled reactor (SS-ABR) for enhancing the processing performance of azo dye-contaminated wastewater. A lab-scale four ecompartment SS-ABR, with a total volume of 10 L, was operated at 30 degrees C for 180 days. A total of 14 polyurethane sponges were added in each compartment to treat synthetic wastewater including a commercial azo dye Hellozol HSR Reactive Black. During the entire operation, in synthetic wastewater, starch was used as a sole carbon source, and the true color level was maintained at 1050 +/- 98 Pt/Co. Meanwhile, the hydraulic retention time (HRT) and total COD (T-COD) in the influent were changed to evaluate the SS-ABR treatment performance. After the start-up phase, true color and T-COD removal efficiencies were recorded as 65 +/- 3% and 83 +/- 2%, 68 +/- 5% and 81 +/- 4%, and 70 +/- 5% and 84 +/- 2% for HRT and influent T-COD concentration of 18.6 h and 260 mg L-1, 14.6 h and 260 mg L-1, and 14.6 h and 460 mg L-1, respectively. The microbial community analysis showed that bacterial groups involved in dye degradation, such as Clostridium sp., and sulfate-reducing bacteria Desulfomonile sp. and Desulfovibrio sp. were detected prominently in the SS-ABR. Interestingly, the SS-ABR exhibited the dominance of both Geobacter sp. and Methanosarcina sp., and their occurrences in all columns were proportional to each other, revealing the formation of syntrophic relationships. (C) 2021 Elsevier Ltd. All rights reserved.