刘超,李如忠,吴小龙.不同污染水平城市河流有机质降解速率及影响因素分析[J].环境科学学报,2021,41(9):3578-3585
不同污染水平城市河流有机质降解速率及影响因素分析
- Degradation rate and influencing factors of organic matter in urban rivers with different pollution levels
- 基金项目：国家自然科学基金项目（No.51579061）；安徽省重点研究与开发计划项目（No.202004i07020005）
- 刘超
- 合肥工业大学资源与环境工程学院, 合肥 230009
- 李如忠
- 合肥工业大学资源与环境工程学院, 合肥 230009
- 吴小龙
- 合肥工业大学资源与环境工程学院, 合肥 230009
- 摘要：为揭示城市不同污染水平河流有机质降解能力的差异，以合肥市十五里河、关镇河和板桥河为对象，选择速生杨（Populus tomentosa Carr.）凋落叶为实验材料，将其装入尼龙网袋并放置于河流水体底部.根据实验前后粗、细网眼尼龙网袋中凋落叶无灰干重，估算有机质降解速率，识别主要环境影响因素.结果表明：①水质状况较好的板桥河凋落叶有机质降解速率相对较低，而污染较为严重的十五里河、关镇河相对较高，变化范围分别为0.0133~0.026（均值为0.0193）、0.0207~0.098（均值为0.0418）和0.0305~0.0543（均值为0.0416） d-1.②2019年3条河流凋落叶有机质降解速率高低排序为：关镇河>十五里河>板桥河；2020年高低排序为：十五里河>关镇河>板桥河.③无论是粗眼网袋还是细眼网袋，每条河流两次实验之间凋落叶降解速率均呈极显著差异，而且3条河流凋落叶有机质降解速率之间也均表现出极显著差异性.④相较于沉积物指标，水质因素对凋落叶有机质降解速率的影响更为明显，特别是TN、NH4+-N、NO3--N、TP、SRP等都与降解速率存在重要或较重要的关系.
- Abstract：To reveal the differences of degradation ability of organic matter in urban streams with different pollution levels, we chose three typical streams including Shiwuli River, Guanzhen Stream, and Banqiao Stream in Hefei City as objects, and selected leaf litter of Populus tomentosa Carr. as experimental materials to conduct field experiments. The leaf litter was put in both coarse and fine nylon mesh bags, respectively, and then placed at the bottom of these streams for several weeks. The degradation rate of organic matter was estimated by measuring the amount of variation in ash free dry mass (AFDM) of the leaf litter before and after decomposition. Moreover, major influencing factors of degradation rate were also identified. Results showed that: ① The degradation rate in Banqiao Stream with good water quality was low, while those in severely polluted Shiwuli River and Guanzhen Stream were high. And their variation ranges were 0.0133~0.026, 0.0207~0.098, and 0.0305~0.0543 d-1 with a mean of 0.0193, 0.0418, and 0.0416 d-1, respectively. ② The order of degradation rate in three streams in 2019 was Guanzhen Stream>Shiwuli River>Banqiao Stream, while the order in 2020 was Shiwuli River > Guanzhen Stream > Banqiao Stream. ③ Regardless of coarse or fine mesh bags, the degradation rates for each stream showed extremely significant differences between the two field experiments in 2019 and 2020, and these differences were also observed among three streams. ④ Effects of water quality factors on the degradation rate was more obvious compared with the sediment indicators, and almost all of them had a major correlation with the degradation rate of organic matter, especially for TN, NH4+-N, NO3--N, TP, SRP.
