摘要
通过2002年4月至2003年4月对川中丘陵区小流域地下水中氮素各种形态的监测分析,研究了该流域地下水硝态氮的时空变化特征。结果表明,川中小流域地下水硝态氮污染特征与流域降水的季节变化趋势基本一致,其污染强度约从6月开始上升,一直持续到10月,集中在降雨丰富的时段。夏季3个月(6月—8月)是地下水硝态氮污染的高发季节,这与年雨量的60%集中于该季节而降水多以暴雨形式出现有关。小流域地下水硝态氮污染强度中以小流域上部为最高,明显高于该流域的中下部。小流域上部的塘边井样点地下水硝态氮浓度平均达11.26mg·L-1,最高值达14.23mg·L-1,超过WHO所规定的生活饮用水NO-3-N浓度上限的42.3%;小流域中下部地下水硝态氮的污染水平相对较小,以张飞井为最低,平均浓度仅为1.03mg·L-1。小流域地下水中氮素存在形态以NO3--N为主,平均占97.6%,最高达99.4%。
Nitrate contamination of the groundwater has aroused nationwide concern recently. All forms of nitrogen concentrations in small watershed of central Siehuan basin were monitored twice a month with two replicates from April 26, 2002 to March 15, 2003. The results dem onstrated that NO3^--N was the major composition of nitrogen in the groundwater. The maximum concentration of NO3^--N was 14.23 mg·L^-1, exceeding by 42.3% the limit of WHO about the drinking water standard. Furthermore, the major pollutant in the groundwater was NO3^--N, which amounted to 97.6% of total N of groundwater and varied with the seasons remarkably. NO3^--N pollution of groundwater showed temporal and spatial effects. NOs-N contents changed with the rainfall along seasonal alteration in the small watershed. The increase of NO3^--N pollution began from June and lasted to October as 60% of the rainfall occurred in this period, and concentrated in the raining season. Especially June, July and August were the seasons when most of NO3^--N pollution happened frequently.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2006年第4期1060-1064,共5页
Journal of Agro-Environment Science
基金
中国科学院知识创新工程重大项目(KZCX2-413-5)
关键词
小流域
地下水
硝态氮
small watershed
groundwater
NO3^--N
