香溪河沉积物、间隙水的磷分布特征及释放通量估算

发布时间：2019-01-30 18:09

【摘要】：采集香溪河沿程5个样点不同季节、不同深度的沉积物,用Hedley分级方法分析磷形态及垂向变化特征,同时研究上覆水和间隙水理化性质对沉积物中磷释放的影响.香溪河上覆水及间隙水pH值范围为4.72~8.55,夏季呈弱酸性,秋季、冬季及次年春季pH值呈弱碱性;沉积物处于较强还原性环境;上覆水及间隙水总磷质量浓度(TP)年变化范围为0.02~0.48mg·L~(-1),沉积物TP含量为0.48~1.45 g·kg~(-1);沉积物中磷形态的含量为HCl-P(HCl提取态)Res-P(残余磷)NaOH-P(NaOH提取态磷)NaHCO_3-P(NaHCO_3提取态磷)H_2O-P(水提取态磷).沉积物-上覆水体交界面还原性环境有利于沉积物中磷向上覆水中释放;春季水体的弱碱性、夏季的弱酸性有利于沉积物向上覆水释磷,从而增加了上覆水体富营养化的风险;间隙水TP与沉积物TP含量密切相关;5个样点中有4个样点的PO_4~(3-)-P由间隙水向上覆水扩散,释放通量为0.01~0.04mg·(m~2·d)~(-1).沉积物是底层水体营养盐的重要来源.
[Abstract]:The sediment samples from 5 sampling sites along the Xiangxi River were collected in different seasons and depths. The characteristics of phosphorus morphology and vertical variation were analyzed by Hedley classification method. The effects of the physicochemical properties of overlying water and interstitial water on phosphorus release from sediments were also studied. The pH value of overlying water and interstitial water of Xiangxi River is 4.72 ~ 8.55, which is weakly acidic in summer, weakly alkaline in autumn, winter and spring, and the sediment is in a strong reductive environment. The annual variation range of total phosphorus concentration (TP) in overlying water and interstitial water is 0.02~0.48mg L ~ (-1), and the content of TP in sediment is 0.48 ~ 1.45 g kg~ (-1). The content of phosphorus forms in sediments is HCl-P (HCl extractable) Res-P (residual phosphorus) NaOH-P (NaOH extractable phosphorus) NaHCO_3-P (NaHCO_3 extracted phosphorus) H_2O-P (water extracted phosphorus). The deoxidizing environment of the interface between sediment and overlying water is favorable to the release of phosphorus from the sediment to the overlying water, the weak acidity of the water in spring and the weak acidity in summer are favorable to the release of phosphorus from the sediment to the overlying water, thus increasing the risk of eutrophication of the overlying water. The PO_4~ (3-) -P of four of the five samples diffused from the interstitial water to the overlying water, and the release flux was 0.01~0.04mg (mc2d) ~ (-1). Sediment is an important source of nutrients in bottom water.
【作者单位】：三峡大学水利与环境学院;三峡大学三峡地区地质灾害与生态环境湖北省协同创新中心;三峡大学三峡库区生态环境教育部工程研究中心;
【基金】：国家水体污染控制与治理科技重大专项(2012ZX07104-003-04) 湖北省科技惠民计划项目(S2013GMD100042) 湖北省自然科学基金创新群体项目(2015CFA021)
【分类号】：X522

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