花津河浅层沉积物粒径营养元素特征及对水质潜在风险的探究

Research on the Grain Size and Nutrient Elements Characteristic of Shallow Sediment and Their Potential Risk to Water Quality in Huajin River

河流、湖泊浅层沉积物与水比邻,会直接或者间接影响水质,为探讨花津河浅层沉积物粒径营养元素特征对水体营养元素与环境的影响,测定了花津河不同位点浅层沉积物样品的粒径和相关养分元素指标,分析其对河流水质的潜在影响。结果表明:①花津河浅层沉积物pH为7.6,TC、TOC、TN、TH、TS分别为26.2、18.7、2.5、7.7、2.6 g/kg,其中C/N为10.48,H/S为3.19。浅层沉积物粒径以粉粒为主,占62%~83%,黏粒和砂粒相对较少,但砂粒在不同采样点变化明显;②花津河沉积物OM为29.39~37.24 g/kg,远大于有机污染标准,河流养分状态属中富营养水平,主要受自然水体扰动和外源有机质输入影响,存在潜在的环境风险;③浅层沉积物粒径性状对其养分状况影响较大,沉积物砂粒与TH呈极显著负相关,相关系数达0.68,仅与养分元素中的TS呈正相关;粉粒与TH呈显著正相关,相关系数达为0.62,仅与TS呈负相关;黏粒与营养各项指标均呈正相关,其中与TH呈极显著正相关,与TN呈显著正相关,相关系数分别为0.71和0.54。因此,内河浅层沉积物养分状况及粒径性状可作为水体环境管理的重要潜在指示物。

Rivers and lakes sediments are adjacent to water,which also affects water quality directly or indirectly.In order to investigate the effects of grain size and nutrient characteristics of the shallow sediments on water environment and bottom nutrient environment,the grain size and related nutrient elements of the shallow sediments in different sites of Huajin River are measured,and then their potential effects on river water quality are analyzed.The results show that:①the pH of the Huajin River shallow sediments is 7.6,and the average contents of TC,TOC,TN,TH,TS of shallow sediments are 26.2,18.7,2.5,7.7 and 2.6 g/kg,respectively.C/N and H/S are 10.48 and.3.19.The grain size of shallow sediments is mainly silt,which accounts for 62%~83%.The content of clay and sand are lower relatively,but the content of sand was significantly different among different sampling points.②Sediment OM varies between 29.39 and 37.24 g/kg,which is much higher than the organic pollution standard.The nutrient status of the river is at the mesotrophic and eutrophic level,which is mainly affected by water disturbance and the input of exogenous organic matter,and thus potential risks to water environment exist.③The grain size of shallow sediment has a great effect on its nutrient status.The sand grains of sediment are negatively correlated with TH,with a correlation coefficient of 0.68,which is only positively correlated with TS in nutrient elements.The silt grains are positively correlated with TH,with a correlation coefficient of 0.62,which is negatively correlated with TS.The clay grains are positively correlated with various nutrient indicators,in which significant positively correlated with TH and TN,with the correlation coefficients are 0.71 and 0.54,respectively.Therefore,the nutrient status and grain size characteristics of river shallow sediments can be used as important potential indicators for water environmental management.