| 摘要: |
| 为探究天然基质表面生物膜群
落对氮磷转化的调控路径及其与水质演
变的耦合关系，本研究针对重庆市盘溪
河9 个点位的水质与基质附着生物膜特征
进行了分析。结果显示，盘溪河水质沿主
河道具有明显的空间异质性，沿上游至下
游方向，水体呈现从轻度富营养化向重度
富营养化的梯度递进特征；同时，上游基
质附着生物膜微生物群落结构单一、生物
量较低、以降解菌为主，下游优势菌转为
光合、固氮功能菌，且生物膜藻类与功能
菌（如Pseudanabaena、Nitrospira）丰度
增加，表明基质附着生物膜的群落结构可
能与水质变化在空间上具有同步性；此
外，二者之间可能还存在互相影响，即水
体中营养盐积累（尤其是当TP>0.5 mg/L，
TN>6 mg/L 时）可以为生物膜发育提供
物质基础，而成熟生物膜会通过改变溶
解氧（DO）、pH等微环境、增强可溶性
磷酸盐截留和溶解性有机碳（DOC）代
谢，进而调控水体理化特征。本文研究
结果为进一步探究富营养化河流自净机
制提供了科学支撑。 |
| 关键词: 水污染 基质 生物膜 营养
盐 生物调控 |
| DOI：10.13791/j.cnki.hsfwest.20250929002 |
| 分类号: |
| 基金项目:重庆市技术创新与应用发展专项重点项目（CSTB2025TIAD-KPX0050）；首创集团创新项目（SCHB202110） |
|
| Correlation and driving pathways between substrate attached biofilms and water quality inrivers: A case study of Panxi River in Chongqing |
|
LI Hong,YANG Tao,HU Jianmei,MA Yuanyuan,ZENG Yi
|
| Abstract: |
| Eutrophication has become a prominent environmental challenge endangering the ecological
health of urban rivers. In Chongqing’s Panxi River, a typical urban watercourse affected by anthropogenic
nutrient inputs, excessive nitrogen (N) and phosphorus (P) loads have disrupted aquatic nutrient cycling,
impairing the river’s natural ecological balance and highlighting the urgent need to clarify the regulatory
role of substrate-attached biofilms in water quality evolution. As key components of river ecosystems,
biofilms on natural substrates (e. g., cobbles and gravels) play a vital role in mediating N and P
biogeochemical cycles; however, their specific regulatory pathways for N and P transformation and
intrinsic coupling relationship with spatiotemporal water quality changes remain to be fully elucidated. To
address this knowledge gap, this study systematically analyzed the water quality and characteristics of
substrate-attached biofilms at 9 sampling sites along the Panxi River, aiming to explore the
aforementioned scientific questions. The 9 sampling sites were strategically selected to cover the
upstream, midstream, and downstream sections of the Panxi River, ensuring the capture of full gradients of
environmental conditions and pollution levels. At each site, key water quality indicators related to
eutrophication were measured, including total nitrogen (TN), total phosphorus (TP), dissolved oxygen
(DO), pH, and dissolved organic carbon (DOC). Meanwhile, substrate-attached biofilms were collected
from the surfaces of natural substrates; their core characteristics, such as microbial community structure,
biomass, algal content (quantified by chlorophyll a), and abundance of functional bacteria, were analyzed
to reveal their response to water quality changes. The upstream biofilm microbial community was
structurally simple, with low biomass dominated by degradative bacteria, while the downstream was
characterized by an increase in photosynthetic and nitrogen-fixing functional bacteria. Biofilm algae
(chlorophyll a reaching 86.33 μg/L) and functional bacteria (such as Pseudanabaena and Nitrospira)
became more abundant, indicating spatial synchronicity between biofilm community structure and water
quality changes. Furthermore, a complex correlation exists between them: the accumulation of nutrients in
the water (especially TP > 0.5 mg/L, TN > 6 mg/L) provides a material basis for biofilm development,
while mature biofilms reshape the physicochemical characteristics of the water by altering
microenvironments (e. g., DO, pH), enhancing soluble phosphate retention , and promoting DOC
metabolism. In conclusion, this study clarifies the spatial coupling pattern between substrate-attached
biofilm communities and water quality in the Panxi River, as well as the bidirectional regulatory
mechanism between nutrient levels and biofilm development. The findings deepen the understanding of
the ecological role of biofilms in urban eutrophic rivers, provide important scientific support for further
exploring the natural self-purification mechanism of eutrophic rivers, and offer valuable theoretical
guidance for the ecological restoration and pollution control of urban river systems. |
| Key words: water pollution substrate biofilm nutrients biological regulation |
