College of Urban Construction, Nanjing Tech University, Nanjing 211800, China.
College of Urban Construction, Nanjing Tech University, Nanjing 211800, China; Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, Nanjing Tech University, Nanjing 211800, China.
Sci Total Environ. 2023 Jan 20;857(Pt 3):159413. doi: 10.1016/j.scitotenv.2022.159413. Epub 2022 Oct 13.
Microorganisms transform nitrogen and phosphorus in the sediment of sewage pipelines. When the sediment was scoured by water flow, these elements migrate. This work studied the changes in biofilm morphology and microbial community structure, and focused on the differences in the transformation of nitrogen and phosphorus along the pipeline. The results showed that the nitrogen and phosphorus concentrations varied systematically with time and space (the front, middle, and posterior segments of the pipe). With time, amino acid nitrogen (AAN) concentration in the sediment gradually decreased, NH-N concentration slowly increased, NO-N concentration began to increase after 25 days, and TP concentration continued to increase after 9 days. The AAN, NH-N, and TP concentrations were highest in the posterior segment of the pipe and lowest in the front segment. However, NO-N showed two stages: its concentration was highest in the front segment and lowest in the posterior segment during the first 17 days, after which the opposite was observed. Changes in the nitrogen and phosphorus concentrations were related to the microbial communities in the sediments. The abundances of Rhodobacter (0.001 <p ≤ 0.01), Trichococcus (p ≤ 0.001), Nakamurella (0.01 <p ≤ 0.05), and norank_f__norank_o__PeM15 (0.001 <p ≤ 0.01) in the terminal sediments were significantly higher than those in the initial sediments. Meanwhile, the abundances of Clostridium_sensu_stricto_1, Rhodobacter, norank_f__norank_o__PeM15, and Brevundimonas were different in the front, middle, and posterior segments. Furthermore, nitrogen and phosphorus were easily adsorbed on the small particles and were scoured and re-deposited on the posterior segment of the pipe, resulting in enrichment. The temporal variation in nitrogen and phosphorus and its spatial distribution along the pipeline were due to the combination of biotransformation and migration.
微生物会转化污水管道沉积物中的氮和磷。当水流冲刷沉积物时，这些元素会迁移。本研究考察了生物膜形态和微生物群落结构的变化，并重点关注了沿管道的氮和磷转化的差异。结果表明，氮和磷的浓度随时间和空间（管前、中、后段）呈现出系统性变化。随着时间的推移，沉积物中氨基酸态氮（AAN）的浓度逐渐降低，NH-N 浓度缓慢增加，NO-N 浓度在 25 天后开始增加，TP 浓度在 9 天后持续增加。AAN、NH-N 和 TP 的浓度在管后段最高，前段最低。然而，NO-N 呈现出两个阶段：在前 17 天，其浓度在前段最高，在管后段最低，之后则相反。氮和磷浓度的变化与沉积物中的微生物群落有关。终末沉积物中 Rhodobacter（0.001<p≤0.01）、Trichococcus（p≤0.001）、Nakamurella（0.01<p≤0.05）和 norank_f__norank_o__PeM15（0.001<p≤0.01）的丰度明显高于初始沉积物。同时，Clostridium_sensu_stricto_1、Rhodobacter、norank_f__norank_o__PeM15 和 Brevundimonas 在管前段、中段和后段的丰度不同。此外，氮和磷容易被小颗粒吸附，在管后段被冲刷和再沉积，导致其富集。氮和磷沿管道时空变化及其空间分布归因于生物转化和迁移的共同作用。
