Pearl River Water Resources Research Institute, Pearl River Water Resources Commission of the Ministry of Water Resources, Guangzhou, China; Key Laboratory of the Pearl River Estuary Regulation and Protection of Ministry of Water Resources, Guangzhou, China; Guangdong Provincial Engineering Technology Research Center for Life and Health of River & Lake, Guangzhou, China.
J Environ Manage. 2024 May;359:120962. doi: 10.1016/j.jenvman.2024.120962. Epub 2024 Apr 26.
Low-water-level regulation has been effectively implemented in the restoration of urban river sediments in Guangzhou City, China. Further investigation is needed to understand the microbial mechanisms involved in pollutant degradation in low-water-level environments. This study examined sediment samples from nine rivers, including low-water-level rivers (LW), tidal waterways (TW), and enclosed rivers (ER). Metagenomic high-throughput sequencing and the Diting pipeline were utilized to investigate the microbial mechanisms involved in sediment C/N/S geochemical cycling during low-water-level regulation. The results reveal that the degree of pollution in LW sediment is lower compared to TW and ER sediment. LW sediment exhibits a higher capacity for pollutant degradation and elimination of black, odorous substances due to its stronger microbial methane oxidation, nitrification, denitrification, anammox, and oxidation of sulfide, sulfite, and thiosulfate. Conversely, TW and ER sediment showcase greater microbial methanogenesis, anaerobic fermentation, and sulfide generation abilities, leading to the persistence of black, odorous substances. Factors such as grit and silt content, nitrate, and ammonia concentrations impacted microbial metabolic pathways. Low-water-level regulation improved the micro-environment for functional microbes, facilitating pollutant removal and preventing black odorous substance accumulation. These findings provide insights into the microbial mechanisms underlying low-water-level regulation technology for sediment restoration in urban rivers.
在中国广州市的城市河流沉积物恢复中，已有效实施低水位调控。需要进一步研究以了解低水位环境中污染物降解涉及的微生物机制。本研究调查了来自九条河流的沉积物样本，包括低水位河流（LW）、潮汐水道（TW）和封闭河流（ER）。利用宏基因组高通量测序和 Diting 管道，研究了低水位调控期间沉积物 C/N/S 地球化学循环中涉及的微生物机制。结果表明，LW 沉积物的污染程度低于 TW 和 ER 沉积物。由于 LW 沉积物具有更强的微生物甲烷氧化、硝化、反硝化、厌氧氨氧化和硫化物、亚硫酸盐和硫代硫酸盐氧化能力，因此具有更高的污染物降解和消除黑臭物质的能力。相比之下，TW 和 ER 沉积物具有更大的微生物产甲烷、厌氧发酵和硫化物生成能力，导致黑臭物质的持续存在。砾石和粉砂含量、硝酸盐和氨浓度等因素影响微生物代谢途径。低水位调控改善了功能微生物的微环境，促进了污染物的去除，防止了黑臭物质的积累。这些发现为城市河流沉积物恢复中低水位调控技术的微生物机制提供了见解。
