李如忠,俞欣,汤宁,刘超.污水厂尾水受纳河段沉积物反硝化速率及对外源碳的响应[J].环境科学学报,2020,40(7):2539-2547
污水厂尾水受纳河段沉积物反硝化速率及对外源碳的响应
- Sediment denitrification rate and its response to exogenous carbon in the stream reach receiving urban sewage treatment plant effluent
- 基金项目：国家自然科学基金（No.51579061）
- 李如忠
- 1. 合肥工业大学资源与环境工程学院, 合肥 230009;2. 纳米矿物与污染控制安徽普通高校重点实验室, 合肥 230009
- 俞欣
- 1. 合肥工业大学资源与环境工程学院, 合肥 230009;2. 纳米矿物与污染控制安徽普通高校重点实验室, 合肥 230009
- 汤宁
- 1. 合肥工业大学资源与环境工程学院, 合肥 230009;2. 纳米矿物与污染控制安徽普通高校重点实验室, 合肥 230009
- 刘超
- 1. 合肥工业大学资源与环境工程学院, 合肥 230009;2. 纳米矿物与污染控制安徽普通高校重点实验室, 合肥 230009
- 摘要：为揭示污水厂尾水排入对河流沉积物反硝化的影响，于2018年10月-2019年6月，在合肥市板桥河的蔡田铺污水处理厂尾水排放口上、下游河段设置4个采样点位，隔月采集上覆水和表层沉积物样，解析沉积物反硝化速率及其时空变化特征，识别主要影响因素；同时，通过对外源碳（葡萄糖）响应的分析，评估沉积物反硝化过程的碳限制性.结果表明，4个采样点的反硝化速率在数值上存在一定的差异性，但并未达到显著性水平（p>0.31）；4个采样点位沉积物反硝化速率都表现为随碳浓度梯度增加而增大、随培养时间延长而下降的特点，表明受纳河段沉积物反硝化作用具有一定的碳限制性，且这种限制具有季节性特征，并以春季和秋季表现得最为明显；上覆水中温度和NO3--N浓度对反硝化速率影响较大，沉积物理化指标对反硝化作用的影响较为显著，且在重要和较重要影响因素方面，尾水排放口上、下游存在明显差异性.
- Abstract：In order to reveal the effect of wastewater treatment plant effluent on the sediment denitrification rate in stream, four sampling points were set at the upper and lower reaches of the tail water discharge outfall of Caitianpu sewage treatment plant in the Banqiao River, a first order stream of the Nanfei River, Hefei City. The benthic sediment and its overlying water samples were collected every other month from October 2018 to April 2019. Subsequently, the sediment denitrification rates and its spatiotemporal characteristics were analyzed, and then the major influencing factors were further identified.Moreover, the microbial carbon limitation was assessed according to the response of the sediment denitrification rates to exogenous carbon (glucose) gradient. The results showed that no significant difference in denitrification rates among the sites was found (p>0.31). On the whole, the rates of sediment denitrification decreased with the increase of incubation time and increased significantly with the increase of the exogenous carbon, suggesting that the denitrification process was limited by carbon. Furthermore, the limitation had significantly seasonal variations and was most pronounced in spring and autumn. Physical and chemical properties of the sediments had a significant influence on the denitrification, and water temperature and NO3- concentration in overlying water had a relatively great effect on the sediment denitrification rate. In the meantime, the differences in the major and relatively major affecting factors for sediment denitrification rates among the upstream and downstream of the effluent outfall were distinct.
