Distributions of phosphorus fractions in the sediments of a river–lake system: a case study in Huai River catchment area, China

Abstract

Phosphorus (P) forms, with respect to sediment characteristics, and an in-stream sluice were studied in the river-lake system, Huai River catchment area, China. The mean of total P in sediments in the mainstream of the Huai River was higher than that in the Hongze Lake. It was found that P fractions varied in the sediments throughout the river and lake. Detrital-P was the dominant P fraction in the mainstream and organic P and detrital-P were the dominant P fractions in the lake, which could indicate: biologically available and non-biologically available forms. Useful information for the interpretation of P fractions could also be obtained from major sediment characteristics. Whether the relations between P fractions and grain size characteristics were significant or weak, 0.125 mm was a threshold grain size for P fraction distribution in sediment. In addition, the Bengbu Sluice, one of the most important in-stream facilities in the Huai River catchment area, regulated not only the transport of P in sediments upstream and downstream of the sluice, but also the distribution of P fractions in the river-lake system. Therefore, it was confirmed that nutrient loadings could be prevented from reaching the watershed, as well as improved ecological diversity by integrating sluice operation.

Effect of magnetic iron-zirconium modified zeolite on the different phosphorus forms in river sediment under aerobic and anoxic conditions

“…The release of phosphorus in the sediment into the overlying water is affected by many factors, such as DO, redox potential, temperature, pH, physical disturbance and biological disturbance, etc (Piao et al 2015). These processes lead to the release of phosphorus in the sediment to water through the dissolution of metal oxides/hydroxides, the mineralization of organic matter, and the exchange of competitive hydroxyl anions (OH À ) with ligands (Zhan et al 2015).…”

“…Different forms of phosphorus in sediment have different release potential. Understanding the effect of adding modified zeolite on the occurrence of phosphorus in sediment is helpful to clarify the mechanism of controlling sediment release by adding modified zeolite (Piao et al 2015). Figure 8 shows the changes of various forms of phosphorus contents in sediment before and after the addition of modified zeolite.…”