永年洼湿地表层沉积物污染评价

Pollution Assessment of Surface Sediment in Yongnianwa Wetland

2017年9月,对河北邯郸永年洼湿地表层沉积物取样调查,分析16个样点表层沉积物的碳、氮、磷、硫含量,并在此基础上评价永年洼湿地的污染水平。研究区域氧化还原电位较低,大部分样点的均低于0,pH值的范围为6.9~7.7,含水率为7.8%~64.0%。总碳含量范围为15.7~39.0 g/kg,平均值为25.0 g/kg,有机碳占比为13.8%~74.2%。总氮含量范围为0.4~1.8 g/kg,其中铵态氮占比为2.4%~5.6%,硝态氮占比为0.2%~2.4%。总磷含量范围为0.7~1.9 g/kg,有效磷占比为0.7%~2.3%。总硫含量范围为0.18~3.4 g/kg。通过综合分析各样点污染指数和有机指数,发现永年洼湿地1-2#、2-2#和3-5#样点的表层沉积物污染较为严重,且主要是有机污染。与同类型湿地比较发现,永年洼湿地沉积物综合污染水平较为严重,有必要降低湿地内源负荷,改善底质厌氧环境,有针对性地开展生态修复。

In September 2017,the surface sediments of Yongnianwa Wetland in Handan,Hebei Province were sampled and investigated.The contents of carbon,nitrogen,phosphorus and sulfur in the surface sediments of 16 samples were analyzed,and the pollution level of Yongnianwa Wetland was evaluated on this basis.The oxidation-reduction potential(ORP)of the study area is low,and the values of most of the samples are below zero.The pH value ranges from 6.9 to 7.7,and the water content is 7.8% to 64.0%.The total carbon content ranges from 15.7 to 39.0 g/kg,with an average of 25.0 g/kg,and organic carbon accounts for 13.8% to 74.2%.The total nitrogen content ranges from 0.4 to 1.8 g/kg,of which ammonium nitrogen accounts for 2.4% to 5.6%,and the nitrate nitrogen accounts from 0.2% to 2.4%.The total phosphorus content ranges from 0.7 to 1.9 g/kg,and the available phosphorus ratio is 0.7% to 2.3%.The total sulfur content ranges from 0.18 to 3.4 g/kg.The surface sediments at 1-2#,2-2# and 3-5# are found to be the most seriously polluted through comprehensive analysis of pollution index and organic index at various points in Yongnianwa Wetland,and it is mainly organic pollution.Compared with the same type of wetland,it is found that the comprehensive pollution level of sediments in Yongnianwa Wetland is relatively serious.Therefore,it is necessary to reduce the internal load of the wetland,improve the anaerobic environment of sediment and carry out ecological restoration.