Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Jinan, 250100, China.
Environmental Engineering Co., Ltd., Shandong Academy of Environmental Science, Jinan, 250100, China.
Appl Microbiol Biotechnol. 2018 Nov;102(21):9389-9398. doi: 10.1007/s00253-018-9386-6. Epub 2018 Sep 27.
Constructed wetland (CW) is popular in wastewater treatment for its prominent advantage of low construction and operation cost. However, the nitrogen removal in conventional CW is usually limited by the low dissolved oxygen (DO) and insufficient electron donor. This paper investigated the nitrogen removal performance and mechanisms in the poly (butylenes succinate)-based CW (PBS-CW) while treating ammonia wastewater under different DO levels. The average DO contents in limited-aeration and full-aeration phases were 1.68 mg L and 5.71 mg L, respectively. Results indicated that, with the ammonia nitrogen loading rate of 25 g N m day, total nitrogen removal ratios in the PBS-CW under the limited-aeration and full-aeration phases were 72% and 99%, respectively. Combined analyses revealed that simultaneous nitrification and denitrification (SND) via nitrite/nitrate were the main microbial nitrogen removal pathways in the aeration phase of the PBS-CW (> 89%). The microbial carrier of biodegradable material was believed to play a significant role in prompting SND performance while dealing with low C/N wastewater. Due to the coexistence of micro-anaerobic zone and carbon supply inside the coated biofilm, the high DO level in the PBS-CW increased the abundance of the nitrifying bacteria (amoA and nxrA), denitrifying bacteria (narG, nirK, nirS, and nosZ), and even anammox bacteria (anammox 16s rRNA). These features are beneficial to many microbial processes which require the simultaneous aerobic, anoxic, and anaerobic environment.
人工湿地（CW）因其建设和运行成本低的显著优势，在废水处理中得到广泛应用。然而，传统 CW 的氮去除通常受到低溶解氧（DO）和不足的电子供体的限制。本文研究了聚丁二酸丁二醇酯（PBS）基 CW（PBS-CW）在不同 DO 水平下处理氨废水时的氮去除性能和机制。限氧和全氧阶段的平均 DO 含量分别为 1.68 mg/L 和 5.71 mg/L。结果表明，在氨氮负荷为 25 g N m day 的条件下，PBS-CW 在限氧和全氧阶段的总氮去除率分别为 72%和 99%。综合分析表明，通过亚硝酸盐/硝酸盐进行的同步硝化反硝化（SND）是 PBS-CW 曝气阶段（>89%）主要的微生物氮去除途径。可生物降解材料的微生物载体被认为在处理低 C/N 废水时对促进 SND 性能起着重要作用。由于涂层生物膜内存在微缺氧区和碳源，PBS-CW 中的高 DO 水平增加了硝化细菌（amoA 和 nxrA）、反硝化细菌（narG、nirK、nirS 和 nosZ）甚至厌氧氨氧化菌（厌氧氨氧化 16s rRNA）的丰度。这些特征有利于许多需要同时有氧、缺氧和厌氧环境的微生物过程。
