积雪中氮、磷污染物浓度及其垂直分布特征

Concentrations of nitrogen and phosphorus pollutants in firn as well as its vertical distribution

分别于2014、2015年采集合肥市区两场典型降雪雪样,对地面积雪按每层1cm进行分层收集,同时采集整体雪样,测定雪样中TN、氨氮、TP和COD。采用一次线性方程对积雪层自下而上方向上对污染物浓度进行趋势拟合。结果表明:(1)积雪层中TN和氨氮按自下而上的方向浓度的线性变化趋势为逐层递减的变化趋势,而TP和COD在积雪中的垂直变化特征不明显。(2)2014、2015年合肥市区两场降雪积雪中的氮、磷污染物主要以TN污染为主,分别为《地表水环境质量标准》(GB 3838—2002)Ⅲ类和劣Ⅴ类水平。与中国其他地区的湿沉降相比,合肥市区降雪积雪中氮、磷污染物浓度基本相近。

Snow samples were collected from Hefei urban area in 2014 and 2015 of two snowfall,including 1 cm per layer samples and integral samples.Then,concentrations of TN,ammonia nitrogen,TP and COD in the snow samples were determined,and vertical variations of pollutants in firn by the direction from bottom to top as well as its overall feature were analyzed by first-order linear fitting equation.Results show that：（1）the concentrations of TN and ammonia nitrogen in firn decrease by the direction from bottom to top,while the variation tendency of TP and COD concentrations was not distinct.（2）TN was the main nitrogen and phosphorus pollutants.TN in the firn in2014 and 2015 reached Ⅲ level and Ⅴ level below of＂Surface water environmental quality standards＂（GB 3838-2002）.Compared with nitrogen and phosphorus pollutants concentrations of wet deposition from other areas in China,the concentration of that in Hefei urban area was similar.