State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
Water Res. 2019 Oct 1;162:87-94. doi: 10.1016/j.watres.2019.06.034. Epub 2019 Jun 14.
Previous research has focused on dissolved organic carbon (DOC) as a surrogate for soluble microbial products (SMPs) and found that temperature has a significant influence on the production of SMP-based DOC (SDOC) during biological processes. Little is known about the SMP-based dissolved organic nitrogen (SDON), although some nitrogenous organic matter has been identified as an important part of SMPs. This study investigated the effect of temperature (8 °C, 15 °C and 25 °C) on the characterization of SMPs in an activated sludge system with special emphasis on SDON. Results showed the positive effect of reduced temperature on SDON production. Fluorescence spectroscopy and ultrahigh-resolution mass spectrometry showed the produced SDON at 8 °C and 15 °C exhibits more lability than at 25 °C. This was also supported by the algal bioassay, indicating the SDON produced at low temperature is highly bioavailable and prone to stimulate algae and microorganisms. In addition, principal component analysis demonstrated that the effect of temperature on the chemical characterization of SDON is different from that of SDOC. Overall, this study highlights the importance of SDON control during biological processes at a low temperature to reduce the potential impact of effluent SMPs on receiving waters or wastewater reuse.
先前的研究主要集中在溶解有机碳（DOC）作为可溶微生物产物（SMPs）的替代物，并发现温度对生物过程中基于 SMP 的 DOC（SDOC）的产生有显著影响。尽管已经确定了一些含氮有机物是 SMPs 的重要组成部分，但对于基于 SMP 的溶解有机氮（SDON）的了解甚少。本研究探讨了温度（8°C、15°C 和 25°C）对活性污泥系统中 SMP 特性的影响，特别强调了 SDON。结果表明，低温对 SDON 产生有积极影响。荧光光谱和超高分辨率质谱表明，在 8°C 和 15°C 下产生的 SDON 比在 25°C 下更不稳定。藻类生物测定也支持了这一点，表明低温下产生的 SDON 具有高度的生物可利用性，容易刺激藻类和微生物。此外，主成分分析表明，温度对 SDON 化学特性的影响与 SDOC 不同。总的来说，本研究强调了在低温下进行生物过程时控制 SDON 的重要性，以降低出水 SMPs 对受纳水体或废水再利用的潜在影响。
