Biodecolourization of azo dye and removal of ammonium by aerobic granular sludge (AGS) was investigated under different growth conditions. AGS not previously exposed to azo dye was able to effectively decolourize azo dye under anaerobic and microaerophilic conditions. Azo dye, total organic carbon and ammoniacal nitrogen removal efficiencies of 89–100%, 79–95% and 9–100%, respectively, were achieved in the AGS reactor operated for 80 days under microaerophilic conditions. Removal of carbon, nitrogen and phosphorus was not impacted by azo dye loading. Azo dye, organic carbon and ammonium were majorly removed in the anoxic period wherein bulk dissolved oxygen was ranged from 0.5 and <0.08 mg L⁻¹. Removal of 60 mg L⁻¹ NH₄⁺-N was associated only with smaller amounts of nitrite build-up (∼5 mg L⁻¹ NO₂⁻-N) and negligible nitrate concentrations. Profiles of nitrogen compounds in individual sequencing batch reactor cycles supported the occurrence of ammonium removal over nitrite pathway. Bacterial community analysis showed enrichment of specific microorganisms capable of decolourizing azo dyes in the dye-decolourizing AGS. Dye decolourization and nutrient removal by AGS under microaerophilic conditions is a novel finding and can be further developed for treating textile wastewaters onsite or after dilution with sewage.

中文翻译：

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好氧颗粒污泥排序间歇反应器中纺织品染料的生物脱色和亚硝酸盐上的铵去除

在不同的生长条件下，研究了偶氮染料的生物脱色和好氧颗粒污泥（AGS）去除铵的能力。以前未接触过偶氮染料的AGS在厌氧和微需氧条件下能够有效地使偶氮染料脱色。在微需氧条件下运行80天的AGS反应器中，偶氮染料，总有机碳和氨氮去除效率分别为89–100％，79–95％和9–100％。碳，氮和磷的去除不受偶氮染料负载量的影响。在缺氧阶段主要去除了偶氮染料，有机碳和铵，在该阶段缺氧的总溶解氧范围为0.5至<0.08 mg L ^-1。去除60 mg L ^-1 NH ₄ ⁺-N仅与少量亚硝酸盐堆积（〜5 mg L ^-1 NO ₂ ^-- N）和可忽略的硝酸盐浓度有关。单个测序间歇反应器循环中氮化合物的分布图支持了亚硝酸盐途径中铵的去除。细菌群落分析表明，能够使偶氮染料脱色的AGS中富含特定的微生物。在微需氧条件下通过AGS进行的染料脱色和营养去除是一个新发现，可以进一步开发用于现场处理或通过污水稀释后处理纺织废水。