府河至白洋淀沿线水体-沉积物中磷形态的分布特征及其影响因素

Distribution characteristics and influencing factors of phosphorus forms in water-sediment from Fu River to Baiyangdian Lake

府河是白洋淀主要入淀河流,研究府河至白洋淀水体和底泥磷形态特征及其主控因素对白洋淀水环境保护具有重要作用.本研究以府河至白洋淀沿线水体和沉积物为研究对象,结合野外采样、室内分析以及统计分析等方法,解析了水体和沉积物不同磷形态在雨季降水期、旱季(调水期和非调水期)的时空分布特征,明确了磷形态之间及其与水体环境因子之间的作用关系.结果表明:不同时期水体总磷(TP-W)含量具有明显差异,从上游到下游呈降低的趋势;降水期TP-W以溶解态无机磷(DIP)为主(17%~91%),调水期以颗粒态磷(PP)为主要形态(36%~65%),非调水期水体磷形态的分布比较均匀.沉积物中总磷(TP-S)从上游到下游呈升高的趋势,沉积物中磷形态在不同时期均以钙结合态磷(HCl-P)为主.RDA分析表明,水体电导率(EC)、水温(T)和pH值对降水期水体和底泥中磷形态有明显的影响,流速、T和总溶解性固体(TDS)、氧化还原电位(ORP)分别是影响调水期和非调水期磷形态的主要环境因子.相关性分析揭示了降水期水体中磷形态受内源影响较小,主要来源于降水导致的面源污染,在调水期主要与沉积物中无机磷(IP)的转化显著相关,非调水期与沉积物有机磷(OP)的释放有关.该研究可为白洋淀入淀河流的水环境治理提供科学依据.

The Fu River is the main inflow river of the Baiyangdian Lake.Investigating the characteristics and controlling factors of phosphorus forms in the water and sediment from the Fu River to the Baiyangdian Lake is of great significance for the protection of the water environment of Baiyangdian Lake.In this study,water and sediment samples were collected along the Fu River and the Baiyangdian Lake,and field sampling,laboratory analysis,and statistical analysis were employed to investigate the spatial and temporal distribution characteristics of different phosphorus forms in water and sediment during the rainy season and dry season(divided into periods of water diversion and non-water diversion).The interaction between different forms of phosphorus and environmental factors in the water was also elucidated.The results demonstrated that total phosphorus content in the water(TPW)exhibited significant temporal differences and decreased from upstream to downstream.Dissolved inorganic phosphorus(DIP)was the primary form of TP-W(17%~91%)during the rainy season,whereas particulate phosphorus(PP)was the dominant form during the water diversion period of dry season(36%~65%).Conversely,the distribution of phosphorus forms in the water was relatively uniform during the non-water diversion season.Total phosphorus content in the sediment(TP-S)increased from upstream to downstream,and Ca-bound phosphorus(HCl-P)was the dominant form of phosphorus in the sediment during different periods.The RDA analysis showed that EC,T,and pH had significant influence on the phosphorus forms in water and sediment during the rainy season.Flow velocity,T,TDS,and ORP were the main environmental factors influencing the phosphorus forms during the water diversion period and non-water diversion period,respectively.Correlation analysis revealed that phosphorus forms in the water during the rainy season were primarily derived from non-point source pollution caused by precipitation and less influenced by endogenous factors.During the water diversion period of dry season,phosphorus forms in the water were significantly related to the transformation of inorganic phosphorus(IP)in the sediment,while during the non-water diversion period of dry season,they were associated with the release of organic phosphorus(OP)from the sediment.These findings can provide scientific support for water environmental management in the inflow rivers of the Baiyangdian Lake.