School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, PR China; School of Ecology, Sun Yat-Sen University, Guangzhou, PR China.
Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, USA.
Environ Int. 2021 Jan;146:106265. doi: 10.1016/j.envint.2020.106265. Epub 2020 Nov 20.
Ibuprofen (IBU) is one of the frequently detected non-steroidal anti-inflammatory drugs (NSAIDs) in wastewater treatment plants (WWTPs) and aquatic environment. However, little is known about the effect of IBU and its biotransformation products (TPs) on different biological sludge systems and aquatic environment. The effects and toxicity of IBU and TPs on three biological sludge systems (i.e., activated sludge (AS), sulfate-reducing bacteria (SRB)-enriched sludge and anaerobic methanogenic (AnM) sludge systems) and aquatic environment were comprehensively evaluated through a long-term operation of three bioreactors and a series of batch experiments. Both of the SRB-enriched sludge and AnM sludge systems were not affected under a long-term exposure to IBU, based on removing organic carbon and sulfur and producing methane. This could be attributed to the high tolerance of functional microbes in the SRB-enriched sludge (e.g., genus Desulfobacter) and AnM sludge systems (e.g., genus Candidatus Methanomethylicus) for IBU. In contrast, IBU had some apparently inhibitory effects on the AS system, such as reduced organic removal efficiency and poor sludge settling. The analysis on microbial community revealed that IBU significantly inhibited the genera involved in organic degradation (e.g., genus Candidatus Competibacter) and also stimulated those genera (e.g., genus Brachymonas) to secret excess extracellular polymeric substances (EPS), which thus caused sludge bulking in the AS system. The toxicity of IBU and its TPs in the effluent of the AS system was also investigated with Vibrio fischeri bioluminescence inhibition tests and quantitative structure activity relationship (QSAR) analysis by ecological structure-activity relationship (ECOSAR) program. The results indicated that the AS system could effectively eliminate the acute toxicity of both IBU and TPs, but a potential chronic toxicity of IBU could still existed, which could be more harmful to aquatic organisms than that of its TPs. These findings provide an insight into the toxic effects of IBU and its TPs on biological sludge systems and ecosystem.
布洛芬（IBU）是废水中经常检测到的非甾体抗炎药（NSAIDs）之一，在污水处理厂（WWTP）和水生环境中。然而，对于 IBU 及其生物转化产物（TPs）对不同生物污泥系统和水生环境的影响知之甚少。通过三个生物反应器的长期运行和一系列批处理实验，综合评价了 IBU 和 TPs 对三种生物污泥系统（即活性污泥（AS）、硫酸盐还原菌（SRB）富集污泥和厌氧产甲烷（AnM）污泥系统）和水生环境的影响和毒性。在长期暴露于 IBU 的情况下，SRB 富集污泥和 AnM 污泥系统均未受到影响，这是基于去除有机碳和硫以及产生甲烷。这可以归因于 SRB 富集污泥（例如，属 Desulfobacter）和 AnM 污泥系统（例如，属 Candidatus Methanomethylicus）中功能微生物对 IBU 的高耐受性。相比之下，IBU 对 AS 系统有一些明显的抑制作用，例如降低有机去除效率和较差的污泥沉降。微生物群落分析表明，IBU 显著抑制了参与有机降解的属（例如，属 Candidatus Competibacter），并刺激了那些属（例如，属 Brachymonas）分泌过多的胞外聚合物（EPS），从而导致 AS 系统中的污泥膨胀。还通过发光细菌生物发光抑制试验和生态结构-活性关系（ECOSAR）程序的定量结构活性关系（QSAR）分析，研究了 AS 系统中 IBU 和其 TPs 的毒性。结果表明，AS 系统可以有效消除 IBU 和 TPs 的急性毒性，但 IBU 仍存在潜在的慢性毒性，对水生生物的危害可能比其 TPs 更大。这些发现为 IBU 及其 TPs 对生物污泥系统和生态系统的毒性作用提供了深入的了解。
