派河清水廊道表层沉积物中磷的赋存形态特征及其环境指示意义

沉积物磷的赋存形态是河流内源释放的关键控制因素之一.以引江济淮—江淮沟通段清水廊道——派河为研究对象,分别测定了派河表层沉积物中总磷、无机磷和有机磷含量,并采用分级提取法分析了有机磷赋存形态,包括活性有机磷(labile organic phosphorus,LOP)、中活性有机磷(moderately labil...

CHARACTERISTICS OF PHOSPHORUS FRACTIONS IN SURFACE SEDIMENT FROM A CLEAR WATER GALLERY IN PAIHE RIVER,AND ITS ENVIRONMENTAL IMPLICATIONS

The fractions distribution of sediment phosphorus is one of the important controlling factors of river endogenous release. In present study, the total phosphorus, inorganic phosphorus and organic phosphorus contents in surface sediments of Paihe River section, the clear water gallery of Yangtze-Huaihe Water Diversion, were determined. The organic phosphorus fractions were explored by the method of graded extraction, including labile organic phosphorus(LOP), moderately labile organic phosphorus(MLOP) and nonlabile organic phosphorus(NOP). And the spatial distribution characteristics of phosphorus fractions were further discussed. The results showed that the total phosphorus content in the surface sediments of Paihe River was 471.17~1509.58 mg/kg, among which the inorganic phosphorus content was 421.83~1325.17 mg/kg, and the organic phosphorus content was 103.29~221.79 mg/kg. Generally, the contents of organic phosphorus fractions followed the order of NOP>LOP>MLOP, and the content of MLOP and NOP were significantly higher in the downstream reach than in the middle and upper reach(P<0.05). The organic phosphorus fractions was related to the physical and chemical properties of sediments. NOP had significant positive correlation with cation exchange capacity(CEC)(P<0.05), MLOP and NOP had significant positive correlation with loss on ignition(LOI)(P<0.05), indicating that the variation of organic matter and CEC in sediments affected the distribution of organic phosphorus fractions. The results of this study indicated that the implementation of the Yangtze-Huaihe Water Diversion project may lead to the endogenous release of phosphorus in sediments. Therefore, after the project implemented, on the basis of reducing exogenous input and endogenous control, ecological monitoring should be strengthened and watershed intelligent management should be conducted.