Qin Ru-Bin, Li Ru-Zhong, Gao Su-di, Zhang Rui-Gang
School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China.
Collage of Civil and Environmental Engineering, Anhui Xinhua University, Hefei 230088, China.
Huan Jing Ke Xue. 2017 Mar 8;38(3):936-945. doi: 10.13227/j.hjkx.201609096.
From May 2015 to June 2016, seasonal sediment samples were collected from three headwater streams in the urban-rural fringe of Hefei, Chaohu Lake basin, China. The nitrogen pollution characteristics of sediments were preliminarily investigated for the three streams. Three metrics, that is, potential nitrification rate (PNR), areal nitrification rate (ANR) and rate of denitrification were quantitatively determined, and their spatial and temporal variations were discussed subsequently. Moreover, the relationship between PNR, ANR or denitrification rate and a list of environmental factors was discriminated by using partial least-squares regression analysis. Results showed that:① Guanzhenhe Distributary was the most polluted stream with a mean content of 4516.39 mg·kg for TN, which was 2.56 and 1.36 times higher than those of Modian Stream and Taochong Stream, respectively. Similarly, the highest values for NH-N and NO-N emerged in Guanzhenhe Distributary while the lowest existed in Modian Stream. ② There were distinct seasonal variations in PNR and ANR, namely, the maximum values emerged in summer, minimum in winter, and almost equivalent in spring and autumn. And the arrangement in order for PNR and ANR was Taochong Stream > Modian Stream > Guanzhenhe Distributary. ③ The mean rate of denitrification in Guanzhenhe Distributary was 10.59 mg·(kg·h), which was 3.16 and 1.75 times higher than those in Modian Stream and Taochong Stream, respectively. In addition, both denitrification rate and denitrification activity in summer were higher than those in spring for the three streams. ④ According to the variable importance plot (), ANR, PNR and rate of denitrification were almost all significantly correlated with such physical and chemical factors as pH, OM, NH-N, NO-N, TN and TP in sediments for the three streams.
2015年5月至2016年6月，在中国巢湖流域合肥城乡结合部的三条源头溪流采集了季节性沉积物样本。对这三条溪流沉积物的氮污染特征进行了初步调查。定量测定了潜在硝化速率（PNR）、面积硝化速率（ANR）和反硝化速率这三个指标，并随后讨论了它们的时空变化。此外，通过偏最小二乘回归分析判别了PNR、ANR或反硝化速率与一系列环境因素之间的关系。结果表明：① 关镇河支流是污染最严重的溪流，总氮平均含量为4516.39mg·kg，分别是磨店溪和陶冲溪的2.56倍和1.36倍。同样，NH-N和NO-N的最高值出现在关镇河支流，而最低值出现在磨店溪。② PNR和ANR存在明显的季节变化，即夏季最高，冬季最低，春秋季几乎相当。PNR和ANR的排列顺序为陶冲溪>磨店溪>关镇河支流。③ 关镇河支流的平均反硝化速率为10.59mg·(kg·h)，分别是磨店溪和陶冲溪的3.16倍和1.75倍。此外，三条溪流夏季的反硝化速率和反硝化活性均高于春季。④ 根据变量重要性图，ANR、PNR和反硝化速率几乎都与三条溪流沉积物中的pH、OM、NH-N、NO-N、TN和TP等理化因素显著相关。
