摘要
通过采集杭州西湖表层底泥,在实验室静态模拟底泥氨氮(NH_4^+-N)和硝态氮(NO_3^--N)的释放,同时研究了DO、温度和pH值对底泥N释放的影响。结果表明,西湖底泥NH_4^+-N主要呈现出正释放,而NO_3^--N则主要为负释放。NH_4^+-N的正释放速率随溶解氧增大而减小,NO_3^--N仅在好氧条件下呈现出正释放。温度通过改变微生物的活性,使底泥NH_4^+-N的正释放速率随温度的升高而增大,NO_3^--N的负释放速率也随温度的升高而增大。不同pH值条件下,NH_4^+-N的正释放速率表现为6.5 mg/(m^2·d)>7.5 mg/(m^2·d)>8.5 mg/(m^2·d)。根据模拟实验数据计算得到西湖全年可溶性无机氮(DIN)的释放量为14.603 t,说明西湖底泥已被严重污染,成为营养元素的释放源。
The release of NH4^+-N and NO3^--N to the overlying water and the influences of DO, temperature and pH on the release rate were probed into through a series of large static simulating experiments. The result showed that NH4^+-N is the main nitrogen form released from sediment in West Lake, and NO3^--N always spread from overlying water to sediment. The release rate of NH4^+-N increased with the increase of dissolved oxygen, but NO3^--N can only spread from overlying water to sediment in aerobic conditions. Both of the positive release rate of NH4^+-N and negative release rate of NO3^--N increased with the temperature. The influence of pH on release rate of NH4^+-N manifest as 6.5〉 7.5〉 8.5. Based on the simulation experiments,the release of inorganic dissolved nitrogen is 14.603 t per year. It illustrated that the sediment in West Lake has been seriously polluted and has became the source of nutrient element.
出处
《环境科技》
2016年第1期46-50,共5页
Environmental Science and Technology
基金
国家自然科学基金"城市湖泊环境地下水氮污染机制及其对富营养化调控的基础研究-以杭州西湖为例"(41373122)
"富营养型湖泊不同分子量溶解性有机质对绿藻富集重金属行为的影响机制研究"(41273129)
关键词
底泥
释放通量
氮
温度
DO
pH
Sediment
Release flux
Nitrogen
Temperature
Dissolved oxygen
pH