National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100124, PR China.
XinKai Water Environmental Investment Co. Ltd., Beijing, 101101, China.
Chemosphere. 2020 Aug;252:126624. doi: 10.1016/j.chemosphere.2020.126624. Epub 2020 Mar 30.
Currently, it is a major challenge for waste water treatment plants (WWTPs) to achieve enhanced nitrogen removal economically and effectively from carbon-limited sewage to meet gradually stringent discharge quality standards. Enhanced nitrogen removal can be achieved by endogenous denitrification (ED) treatment of low C/N municipal sewage, but its application is limited by the slow reaction rate. In this study, a novel process of Sludge Double Recirculation-Anaerobic/Aerobic/Anoxic (SDR-AOA) was developed to improve nitrogen removal efficiency via ED. ED was successfully enhanced by an extra sludge recirculation to post-anoxic zone and the denitrification rate increased from 0.1 to 0.17 kgN/(m·d). Moreover, the pre-anaerobic zone enhanced the intracellular carbon storage, which might also favor the ED process. Overall, under an influent C/N of 2.67, nitrogen removal efficiency of 97.7% was achieved with effluent total inorganic nitrogen (TIN) of 1.56 ± 1.77 mg/L and nitrogen removal rate (NRR) of 0.14 kgN/(m·d). Therefore, this study provides a convenient approach to improve the nitrogen removal efficiency of municipal sewage with low C/N.
目前，污水处理厂（WWTPs）面临的一个主要挑战是，如何在经济有效地从碳限制污水中去除增强的氮，以满足逐渐严格的排放标准。通过低 C/N 城市污水的内源性反硝化（ED）处理可以实现增强的氮去除，但由于反应速率较慢，其应用受到限制。在本研究中，开发了一种新型的污泥双循环-厌氧/好氧/缺氧（SDR-AOA）工艺，通过 ED 提高氮去除效率。通过向缺氧区额外的污泥循环，成功地增强了 ED，脱氮速率从 0.1 增加到 0.17 kgN/（m·d）。此外，预厌氧区增强了细胞内碳储存，这也有利于 ED 过程。总的来说，在进水 C/N 为 2.67 的情况下，出水总无机氮（TIN）为 1.56±1.77 mg/L，氮去除率（NRR）为 0.14 kgN/（m·d），实现了 97.7%的氮去除效率。因此，本研究为提高低 C/N 城市污水的氮去除效率提供了一种简便的方法。
