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NO-3-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.
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 NO-3 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.
作者
李如忠
俞欣
汤宁
刘超
LI Ruzhong;YU Xin;TANG Ning;LIU Chao(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009;Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes,Hefei University of Technology,Hefei 230009)
出处
《环境科学学报》
CAS
CSCD
北大核心
2020年第7期2539-2547,共9页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.51579061)。
关键词
污水厂尾水
沉积物
反硝化速率
外源碳
巢湖
sewage treatment plant effluent
sediment
denitrification rate
exogenous carbon
Lake Chaohu