为了考察好氧颗粒污泥在酸性红14(Acid Red 14,ARM)废水中的形成以及降解AR14的能力,在序批式反应器(Sequencing Batch Reactor,SBR)内以蔗糖和AR14为底物培养好氧颗粒污泥。在第1阶段(1~75d),采用单一好氧的运行方式,好氧颗粒污泥出现在第29d,粒径为(0.16±0.04)mm。随着反应器内的COD逐步增加,好氧颗粒污泥的粒径逐步增大;在此阶段AR14脱色率在5%左右,为吸附所致。在第11阶段(75-120d),采用厌氧+好氧的方式运行,驯化好氧颗粒污泥降解AR14的能力。反应器中AR14的脱色率逐步上升,在第102d时,脱色率达到89%,并稳定在此水平。在第120d,污泥质量浓度达到10548mg/L,平均粒径也达到了(2.18±0.25)mill。此时好氧颗粒污泥的沉降性能良好,污泥容积指数稳定在38mL/g。研究表明,可在AR14废水中成功培养获得好氧颗粒污泥且能稳定维持。蔗糖在第11阶段的厌氧反应过程中充当了AR14的共代谢底物,氧化还原电位(Oxidation Reduction Potential,ORP)在此过程中维持在-250-300mV,是偶氮染料生物厌氧降解过程的一个重要控制参数。
The aerobic granular sludge(AGS) was cultivated in a sequencing batch reactor(SBR) treating synthetic Acid Red 14(AR14) wastewater with sucrose as co-substrate. The possible AR14 biodegradation mechanism was also investigated. During phase I, the SBR was run in aerobic mode with COD increasing gradually, the AGS appeared on day 29, mean diameter of AGS was (0.16 ± 0.04) mm, the particle size of AGS increased gradually with the increasing COD. However, reduction of AR14 did not occur under aerobic condition. The decolorization rate was only 5 % in phase I, adsorption may be the reason. During phase II, the SBR was run in anaerobic/aerobic mode, the AR14 decolorization rate increased gradually. On day 102, the decolorization rate increased up to 89% and was kept on the level steadily. On day 120, the MLSS increased to 10 548 mg/L, the average diameter of AGS was (2.18±0.25) mm and sludge volume index was maintained at 38 mL/g. There were lots of bacilli on the surface of AGS, but cocci in the inner part, and no filamentous bacteria were found. The existence of AR14 effectively promoted the sta- bility of aerobic granular sludge. Oxidation reduction potential(ORP) decreased to - 250 mV to - 300 mV under anaerobic condition of phase II, and the reduction of AR14 occurred. In the anaerobic peri- od, sucrose was not only used as the carbon source of AGS cultivation but also acted as a co-metabolism substrate of AR14 degradation. This study shows that AGS could be successfully cultivated and stably maintain the treatment of AR14 wastewater. ORP was a very important process control parameter in the anaerobic degradation of azo dyes.