The role of heterotrophic and nitrifying microorganisms in the (co-)metabolic biotransformation of 10 pharmaceutically active compounds (PhACs) was investigated. To this aim, biotransformation assays were performed with heterotrophic and nitrifying sludge developed separately in a two-stage full-scale activated sludge system. Each stage was operated at different inflow wastewater characteristics and sludge retention times (on average 8 d and 35 d). The biotransformation capacity of each sludge was evaluated in the absence of primary substrate and in the presence of acetate and ammonium, to independently elucidate the co-metabolic role of heterotrophs and nitrifiers present in both sludges. Trimethoprim, diclofenac and carbamazepine were recalcitrant (removal < 5% after 1 d; biotransformation rate < 50 µg/g VSS·d) under all the tested conditions. High concentrations of caffeine, acetaminophen and iopromide were quickly biotransformed (> 80% after 1 d; > 800 µg/g VSS·d) in the absence of primary substrates. The heterotrophic sludge only showed a co-metabolic effect towards erythromycin, which increased its biotransformation rate between 43% and 53% when acetate and ammonium were supplied. In contrast, when stimulated, nitrifiers and slow-growing heterotrophs present in the nitrifying sludge co-metabolically biotransformed acetaminophen, ibuprofen and naproxen to a significant extent. Sulfamethoxazole was recalcitrant, except when the nitrifying sludge was fed with acetate (> 800 µg/g VSS·d), suggesting that slow-growing heterotrophs co-metabolically biotransformed it. This study provides evidence that biotransformation of PhACs depends on several metabolic activities, as the heterotrophic activity of the nitrifying sludge, which are not only determined by the SRT but also by the feeding composition.

研究了异养微生物和硝化微生物在10种药物活性化合物（PhAC）的（共）代谢生物转化中的作用。为此，在两步满规模活性污泥系统中分别开发了异养和硝化污泥，进行了生物转化分析。每个阶段均在不同的流入废水特性和污泥保留时间（平均8 d和35 d）下运行。在没有主要底物的情况下，在存在乙酸盐和铵的情况下，对每种污泥的生物转化能力进行了评估，以独立阐明两种污泥中存在的异养菌和硝化剂的协同代谢作用。甲氧苄啶，双氯芬酸和卡马西平是顽固的（1 d后去除率<5％；生物转化率< 在所有测试条件下为50 µg / g VSS·d）。在没有主要底物的情况下，高浓度的咖啡因，对乙酰氨基酚和碘普罗米迅速生物转化（1天后> 80％；> 800 µg / g VSS·d）。异养污泥仅对红霉素表现出协同代谢作用，当供应乙酸盐和铵盐时，其生物转化率提高了43％至53％。相反，当被刺激时，硝化污泥中存在的硝化剂和缓慢生长的异养菌在很大程度上协同代谢生物转化了对乙酰氨基酚，布洛芬和萘普生。磺胺甲恶唑是顽强的，除了硝化污泥中加入乙酸盐（> 800 µg / g VSS·d）外，这表明缓慢生长的异养生物共同代谢了该生物。