洱海入湖河口湿地干湿季沉积物氮、磷、有机质垂向分布特征及污染风险差异性  

Vertical Distribution and Pollution Risk Assessment of Nitrogen,Phosphorus,and Organic Matter in Sediment of Inflowing Rivers of Erhai Lake Estuarine Wetland in Wet and Dry Seasons

作　　者：王书锦[1] 刘云根[1,2] 王妍[1,2] 侯磊[1,2] 张超[3] 

机构地区：[1]西南林业大学环境科学与工程学院,昆明650224 [2]西南林业大学农村污水处理研究所,昆明650224 [3]西南林业大学林学院,昆明650224

出　　处：《环境科学》2016年第12期4615-4625,共11页Environmental Science

基　　金：国家自然科学基金项目(51469030;31560237;31460195)

摘　　要：以云南洱海罗时江河口湿地为典型对象,利用柱状底泥分层采样器采集罗时江河口湿地表层(0~10 cm)、中层(10~30 cm)和底层(30~60 cm)沉积物样品,分析干、湿季沉积物总氮(TN)、总磷(TP)、有机质(OM)垂向分布特征,并对沉积物进行污染风险评价.结果表明:1干季罗时江河口湿地表层、中层和底层沉积物TN平均含量分别为1.734、1.453和1.255g·kg^(-1),TP平均值分别1.085、1.034和0.992 g·kg^(-1),OM平均值分别为59.051、47.730和42.133 g·kg^(-1);湿季罗时江河口湿地表层、中层和底层沉积物TN平均含量分别为1.147、0.948和0.895 g·kg^(-1),TP平均值分别0.599、0.523和0.519g·kg^(-1),OM平均值分别为53.098、46.897和43.395 g·kg^(-1);干、湿季各指标含量垂向分布随沉积深度的增加呈下降趋势,表层富集明显;三层沉积物各指标含量均为干季高于湿季,且除OM外,TN和TP均达到显著差异(P<0.01).2单因子指数(PI)、有机氮指数(ON)和有机指数(OI)评价结果表明,整体上干季沉积物氮磷属于重度污染,有机质属于中度污染;湿季沉积物氮和有机质均为中度污染,磷为轻度污染;总体上沉积物氮、磷、有机质污染水平为干季高于湿季,且干、湿季各污染指数均为表层最高,中层次之,底层最低,表层污染最为严重.3干、湿季罗时江河口湿地污染来源存在差异,干季以外源为主,湿季以内源为主;干季沉积物营养盐潜在释放风险较湿季大,且以表层释放风险最大.The estuarine wetland of Luoshijiang River,which flows into Erhai Lake in Yunnan province,was regarded as the typical research object. Sediment samples in the estuarine wetland of Luoshijiang River were collected by the cylindrical sediment sampler and the samples were from surface layer（ 0-10cm）,middle layer（ 10-30 cm）,and bottom layer（ 30-60 cm）. The vertical distribution of total nitrogen,total phosphorus,and total organic material in dry and rainy season was analyzed and contamination risk assessment of sediment was accomplished. The results showed that： 1 In dry season,average concentrations of total nitrogen in sediment on surface,middle and bottom layer at estuarine wetland of Luoshijiang River were respectively 1. 734,1. 453 and 1. 255 g·kg^-1,the average concentrations of total phosphorus were respectively 1. 085,1. 034 and 0. 992 g·kg^-1,the average concentrations of organic material were respectively 59. 051,47. 730 and 42. 133 g·kg^-1. In rainy season,average concentrations of total nitrogen in sediment on surface,middle and bottom layer at estuarine wetland of Luoshijiang River were respectively 1. 147,0. 948 and 0. 895 g·kg^-1,the average concentrations of total phosphorus were respectively 0. 599,0. 523 and 0. 519 g·kg^-1,the average concentrations of organic material were respectively 53. 098,46. 897 and 43. 395 g·kg^-1. 2 Single factor pollution index,organic nitrogen and organic index assessment were used to evaluate the contamination level of sediment,the assessment results showed that： In dry season, the contamination level of nitrogen and phosphorus in sediment was on severe level,organic material contamination was on medium level. In rainy season,the contamination levels of ON and OI were medium,and that of PI was mild. Generally,the contamination levels of nitrogen,phosphorus and organic material in sediment tendency were as follows： dry season 〉rainy season,and the pollution index of each layer followed the sequence of surface layer 〉middle layer〉 bottom layer

关 键 词：洱海流域 罗时江河口湿地 沉积物氮、磷、有机质 干、湿季垂向分布特征 污染风险评价 

分 类 号：X52[环境科学与工程—环境工程] X53