Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Longhua Innovation Institute for Biotechnology, Shenzhen University, Shenzhen, 518055, China; Anhui Province Key Laboratory of Environmental Hormone and Reproduction, College of Biology and Food engineering, Fuyang Normal University, Fuyang, 236037, China.
Guangdong Technology Research Center for Marine Algal Bioengineering, Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
Chemosphere. 2023 Oct;339:139685. doi: 10.1016/j.chemosphere.2023.139685. Epub 2023 Jul 31.
In highly salinized environments, nitrification is the process that limits the rate of nitrogen transformation and removal. Therefore, this study concentrated on the impacts of different aeration strategies and NH-N loads on the nitrification performance of mangrove constructed wetlands (CWs), as well as investigating the succession mechanism of ammonia-oxidizing microorganisms (AOMs). The results showed that both the CW with continuous aeration (CA-CW) and intermittent aeration (IA-CW) achieved a nitrification efficiency of more than 98% under an NH-N loading of 1.25-4.7 g/(m·d). However, the total nitrogen removal rates of IA-CW under low and high ammonia-nitrogen loads (LAL, 20.09 ± 4.4% and HAL, 8.77 ± 1.35%, respectively) were higher than those of CA-CW (16.11 ± 4.7% and 3.32 ± 2.3%, respectively), especially under HAL (p < 0.05). Pearson correlation analysis showed that under different operating conditions, the differential secretion of Kandelia candel rhizosphere organic matter had a certain regulatory effect on nitrification and denitrification groups such as Candidatus Nitrocosmicus, Nitrancea, Truepera, Pontibacter, Halomonas, and Sulfurovum in the wetland root layer. The quantitative polymerase chain reaction revealed that the NH-N load rate was the primary factor driving the succession of the AOMs, with different aeration strategies exacerbating this process. Overall, this study revealed that the dominant AOMs in mangrove CWs could be significantly altered by regulating the aeration modes and pollution loads to adjust the rhizosphere organic matter in situ, thereby resulting in more efficient nitrification.
在高盐环境中，硝化作用是限制氮转化和去除速率的过程。因此，本研究集中于不同曝气策略和 NH-N 负荷对红树林人工湿地（CWs）硝化性能的影响，以及调查氨氧化微生物（AOMs）的演替机制。结果表明，在 NH-N 负荷为 1.25-4.7 g/（m·d）的条件下，连续曝气（CA-CW）和间歇曝气（IA-CW）的 CW 都实现了超过 98%的硝化效率。然而，IA-CW 在低和高氨氮负荷下（LAL，分别为 20.09±4.4%和 HAL，8.77±1.35%）的总氮去除率高于 CA-CW（分别为 16.11±4.7%和 3.32±2.3%），尤其是在 HAL 下（p<0.05）。Pearson 相关分析表明，在不同的运行条件下，红树植物秋茄根际有机物质的差异分泌对湿地根层中的硝化和反硝化菌群（如Candidatus Nitrocosmicus、Nitrancea、Truepera、Pontibacter、Halomonas 和 Sulfurovum）有一定的调节作用。定量聚合酶链反应表明，NH-N 负荷率是驱动 AOMs 演替的主要因素，不同的曝气策略加剧了这一过程。总体而言，本研究表明，通过调节曝气模式和污染负荷来原位调整根际有机物质，可以显著改变红树林 CWs 中的优势 AOMs，从而实现更高效的硝化。
