Distribution Of Phosphorus In Different Scales Under Sediment Disturbance

The sediments resuspension caused by the hydraulic disturbance have shown great influence on the phosphorus migration process in waterbody. As one of the characteristic parameters, the diameters of the sediments and suspensions are significant indicators on the precipitation and adsorption processes of phosphorus. As few studies have reported the phosphorus migration behaviors under the influence of various distribution of particle diameters, hence, it's significant and meaningful to understand the distribution of different forms of phosphorus under various physical conditions by studying the phosphorus distribution in the overlaying water under different diameters of suspensions, and the corresponding quantities of different phosphorus forms both in the overlaying water and the sediments. The sufficient information of these studies can be used to enrich the migration studies of phosphorus in waterbody, and can be referred to provide informative theoretical basis for the practical remediation of the waterbody as well. On the other hand, in order to better observe and comprehend the adsorption process of phosphorus by the suspensions and sediments, all the previous experiments were accompanied with a set of reference group with the addition of exogenous phosphorous.The studies have shown that no obvious change of diameters of the suspensions in the overlaying water was observed in stilled water, while the quantities of different forms of phosphorous and the diameters of suspensions various obviously in the overlaying water under intermittent disturbance, the macro-particles show an increasing tendency, which indicates the proportion of macro-particles increased in the overlaying water under hydraulic disturbance. And on the other hand, the correlation analysis of the diameter variations and the quantity variations of different types of phosphorous showed that there was no significant correlations between phosphorous quantity variation and the diameter change in the stilled water of E1 and E3, while showed significant correlations with the disturbed samples of E2 and E4,which indicates the diameter conditions in the overlaying water have great influence on the quantity change of phosphorous. On the other hand, the data analysis of the exogenous phosphorous sample showed that 95% of phosphorous adsorption was augmented by micro-particles and 20% was increased by the macro-particles, this indicates the adsorption augment of phosphorous was majorly caused by the micro-particles.Based on the results of the significant correlations between the quantities of different phosphorous forms and the suspensions diameters in previous study, the latter studies were focused on the distributions of various forms phosphorous in different diameters of suspensions in overlaying water and the sediments. The results showed that the suspensions in A2 scale had the most adsorption amount of phosphorous in most cases, this might be owing to the characteristic properties of the suspensions in A2 under the disturbed conditions. While in viewing of the contributions of DIP and TP values, the ratios of DIP/TP in the A2 scale of stilled samples were the highest, and the corresponding highest ratios in disturbed samples were in A3 scale, which might had some relations with the different phosphorous fixabilities of suspensions. The analyses of the phosphorous quantities in different forms of sediments showed that the sediments under the disturbed conditions had higher amount of phosphorous adsorption capacities compared with the stilled one by viewing of the Tot-P values. And higher amount of TP was observed in sediments with smaller diameters. In viewing of the NH4Cl-P values in different magnitudes of sediments, higher amount of NH4Cl-P was observed in smaller magnitudes of sediments in the disturbed samples of E2 and E4, while the samples of E3 with exogenous phosphorous showed no obvious phosphorous adsorption change in various magnitudes of sediments. In viewing of the Fe/Al-P values in different magnitudes of sediments, only the decreased adsorption was observed in E2 in smaller magnitudes of sediments, while increased adsorption was boserved in E3 in smaller magnitudes of sediments. Besides, with more complex physical environment in E4, there is no obvious phosphorous adsorption change in various magnitudes of sediments.In viewing of the Ca-P values in different magnitudes of sediments, while the highest phosphorous adsorption was observed in middle magnitude of sediments in E2 and E4 with sediments disturbanced, little change was observed in different magnitudes of sediments in E1 and E3,which have static water environment.