State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090, PR China.
J Hazard Mater. 2012 Nov 15;239-240:257-64. doi: 10.1016/j.jhazmat.2012.08.072. Epub 2012 Sep 4.
Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.
偶氮染料含有大量的染料废水，具有毒性且不易生物降解，因此在排放到水体之前必须进行处理。本研究采用无膜连续上流生物催化电解反应器（UBER）和后续好氧生物接触氧化反应器（ABOR）的组合生物系统对茜素黄 R（AYR）偶氮染料进行脱色处理。在 UBER 中施加 0.5 V 的外加电源，可将 AYR 的脱色效率提高到 94.8±1.5%。PPD 和 5-ASA 的生成效率均高于 90%和 60%。在水力停留时间（HRT）大于 6 h 时，基于阴极区 AYR 去除的电子回收效率接近 100%。在较高的 AYR 负荷率（>780 gm(-3) d(-1)）下，较高浓度的 AYR 可能会抑制阳极好氧呼吸菌对乙酸的氧化，从而降低 UBER 中的电流密度；UBER 的最佳 AYR 负荷率为 680 gm(-3) d(-1)（HRT 2.5 h）。随后的 ABOR 进一步改善了出水水质。总的来说，在组合生物系统中，色度从 320 倍降低到 80 倍，达到了中国纺织废水排放标准 II。
