Singh Poonam, Sanghi Rashmi, Pandey Anjali, Iyengar Leela
Biotechnology laboratory, Department of Chemistry, IIT, Kanpur 208 016, India.
Bioresour Technol. 2007 Jul;98(10):2053-6. doi: 10.1016/j.biortech.2006.08.004. Epub 2006 Oct 10.
Decolorization of two monoazo dyes, acid orange 6 (AO6) and acid orange 7 (AO7), were studied in sequential fixed-film anaerobic batch reactor (SFABR) with varying dye concentrations and 500 mg/L glucose as the co-substrate. More than 90% dye decolorization could be achieved, even at 300 mg/L, with both AO6 and AO7 and dye decolorization rates were 168 mg/L/d and 176 mg/L/d, respectively. COD removals with these two monoazo dyes were significantly different, as 75% and 35% decrease were observed with AO6 and AO7, respectively. UV-visible spectral as well as HPLC analysis of SFABR treated effluent showed the accumulation of 4-aminobenzenesulfonate (4-ABS) from AO6 and AO7. Aminoresorcinol (AR) formed from AO6 decolorization could not be detected at the end of SFABR cycle. This along with high COD removal indicated its further degradation. Formation of pink coloration on exposure to air indicated the presence of 1-amino-2-naphthol (AN) in AO7 fed reactor effluent. Thus both 4-ABS and AN were resistant to further degradation under anaerobic conditions. Presence of nitrate did not decrease the observed decolorization at the end of 24h SFABR cycle, although initial rate was decreased. This indicates the suitability of SFABR configuration for the treatment of azo-dye containing wastewaters in the presence of nitrate.
在序批式固定膜厌氧反应器（SFABR）中，以500mg/L葡萄糖作为共底物，研究了两种单偶氮染料酸性橙6（AO6）和酸性橙7（AO7）在不同染料浓度下的脱色情况。即使在染料浓度为300mg/L时，AO6和AO7的脱色率均可达到90%以上，脱色速率分别为168mg/L/d和176mg/L/d。这两种单偶氮染料的化学需氧量（COD）去除率存在显著差异，AO6和AO7的COD去除率分别降低了75%和35%。对经SFABR处理后的出水进行紫外可见光谱和高效液相色谱分析，结果表明AO6和AO7降解过程中积累了4-氨基苯磺酸盐（4-ABS）。在SFABR运行周期结束时，未检测到AO6脱色产生的氨基间苯二酚（AR）。这与较高的COD去除率表明其进一步降解。AO7进水的反应器出水中，暴露于空气中会形成粉红色，表明存在1-氨基-2-萘酚（AN）。因此，4-ABS和AN在厌氧条件下均难以进一步降解。尽管初始速率有所降低，但在24小时SFABR运行周期结束时，硝酸盐的存在并未降低观察到的脱色率。这表明SFABR构型适用于处理含硝酸盐的偶氮染料废水。
