Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis
Hong-Cheng Wang , Hao-Yi Cheng
,
Shu-Sen Wang
,
Dan Cui
,
Jing-Long Han
,
Ya-Ping Hu
,
Shi-Gang Su
,
Ai-Jie Wang
DOI:10.1016/j.jes.2015.10.014
Received August 08, 2015,Revised September 26, 2015, Accepted October 11, 2015, Available online December 30, 2015
Volume 28,2016,Pages 198-207
In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3% ± 2.5%, 86.2% ± 3.8% and 93.5% ± 1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1% ± 4.7%, 75.4% ± 5.0% and 82.1% ± 2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2% ± 3.7% and 28.30 ± 1.48 mA, respectively. They were significantly increased to 62.1% ± 2.0% and 34.55 ± 0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.
