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

发布时间：2018-06-21 19:43

本文选题：洱海流域 + 罗时江河口湿地　；参考：《环境科学》2016年12期

【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(P0.01).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.
[Abstract]:Taking Luoshi River estuary wetland in Erhai, Yunnan Province as a typical object, the sediment samples were collected from the surface layer of Luohe River mouth wetland of Luoshi River mouth, Yunnan Province, with a stratified sampler of columnar sediment of 10 ~ 10 cm ~ (10 ~ (30) cm) and a bottom layer of 30 ~ 60 cm). The vertical distribution characteristics of total nitrogen (TNN), total phosphorus (TP) and organic matter (OM) in wet season sediments were analyzed, and the pollution risk was evaluated. The results showed that the average TN contents in the surface, middle and bottom sediments of the Wetland at the Luoshi River Estuary were 1.7344.53 and 1.255g / kg ~ (-1) ~ (-1), respectively, 1.085 ~ 1.034 and 0.992 g 路kg ~ (-1) 路m ~ (-1), 59.051g / 47.730 and 42.133 g / kg ~ (-1) ~ (-1), respectively, and the mean value of TN was 59.051g / kg ~ (-1) and 42.133 g / kg ~ (-1) 路kg ~ (-1), respectively. The average TN contents of middle and bottom sediments were 1.1470.48 and 0.895 g / kg 路kg ~ (-1) ~ (-1), respectively, 0.599g / 0.523 and 0.519 g / kg ~ (-1) respectively were 53.09897 and 43.395 g / kg ~ (-1) respectively, the vertical distribution of indexes in dry and wet seasons showed a downward trend with the increase of sediment depth, and the surface layer was obviously enriched. The contents of each index in the three layers of sediments were higher in dry season than in wet season, and there were significant differences between TN and TP except OM. The evaluation results showed that the nitrogen and phosphorus in the whole dry season were seriously polluted, and the single factor index (PIP), organic nitrogen index (ON) and organic index (OII) were significantly different. Organic matter belongs to moderate pollution; sediment nitrogen and organic matter are moderately polluted and phosphorus is slightly polluted in wet season; in general, the pollution level of nitrogen, phosphorus and organic matter in sediment is higher in dry season than in wet season, and the pollution index in dry season is the highest in surface layer. In the middle level, the bottom layer is the lowest, the surface pollution is the most serious, the source of pollution in Luoshijianghe estuary wetland is different in the wet season, the main source is outside the dry season, and the main source is in the wet season, and the potential release risk of nutrients in the dry season is greater than that in the wet season. The risk of surface release is the greatest.
【作者单位】：西南林业大学环境科学与工程学院;西南林业大学农村污水处理研究所;西南林业大学林学院;
【基金】：国家自然科学基金项目(51469030,31560237,31460195)
【分类号】：X52

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