丰乐河夏季非洪水期与洪水期河水和底泥不同形态磷研究

Phosphorus fractionation in river water and sediment during non-flood and flood periods in Fengle River in summer

磷是水体富营养化的主要限制性元素之一,河流输送是受纳水体中磷的主要来源。为了解在不同水文条件下河流不同形态磷含量的变化特征,选择巢湖主要入湖河流丰乐河,通过在夏季非洪水期与洪水期,对河水和底泥进行分布式采样,水样测定总磷(TP)和可溶性磷(DP),底泥测定总磷(TP)、有机磷(OP)、无机磷(IP)、氢氧化钠磷(NaOHP)和盐酸磷(HCL-P)。结果 显示:非洪水期河水TP、DP均值含量分别为0.095,0.063mg/L,DP占TP的均值比例为65.9%,说明丰乐河非洪水期存在着富营养化风险。洪水期河水TP、DP均值含量分别为0.174,0.085mg/L,显著高于非洪水期,洪水期河水对磷的输送更强。非洪水期底泥中TP平均含量为520.09mg/kg,以IP为主,IP中HCL-P含量略高于NaOH-P,洪水期底泥中各形态磷含量与非洪水期相比总体水平差别较小。

Phosphorus is one of the main limiting elements in water eutrophication and river exporting is the main source of phosphorus in its receiving water.In order to understand phosphorus fractionation in rivers under different hydrological conditions,samples of water and sediment were taken from distributed sampling sites of Fengle River,one of the main inflowing rivers of Chaohu Lake basin,in non-flood and flood periods in summer.Water samples were analyzed for total phosphorus(TP) and dissolved phosphorus(DP) and sediments for TP,organic phosphorus(OP),inorganic phosphorus(IP),NaOH-P,and HCL-P.The results showed that during the non-flood period the average contents of TP and DP in water were0.095 mg/L and 0.063 mg/L,respectively,with the average DP-TP ratio being 65.9%.There was a risk of eutrophication in Fengle River during the non-flood period.During the flood period,the contents of TP and DP in water were 0.174 mg/L and0.085 mg/L,respectively,much higher than that during the non-flood period,demonstrating stronger phosphorus export during the flood period.As for the sediment,during the non-flood period,the average content of TP was 520.09 mg/kg,with IP being the main constituent.In IP,the content of HCL-P was slightly higher than that of NaOH-P.The contents of the various forms of phosphorus in sediment during the flood period had a small difference compared with that in the non-flood period.