泥沙级配与成分对磷吸附作用影响试验研究

Experimental study on the effect of sediment gradation and component on phosphorus adsorption

泥沙是水体中磷元素的重要载体,研究泥沙自身特性与磷吸附作用的相关关系对于了解磷在水体中的输运过程具有重要意义。为更加清晰地揭示不同级配和组分对泥沙吸附磷的影响机理,采用江苏沿海现场采集的泥沙进行恒温振荡试验,研究不同中值粒径和黏土含量的泥沙对磷的平衡吸附量和对固体浓度效应的响应。研究结果表明,黏土是泥沙对磷吸附作用的关键,黏土含量高的泥沙对磷具有更强的吸附能力,以黏土含量为变量的公式能更好地表现泥沙对磷的吸附现象。对于粗颗粒和细颗粒泥沙,固体浓度效应均导致单位质量泥沙对磷吸附量下降,在0.5~2.5 g/L的泥沙浓度范围内,两者响应趋势存在差异。

Sediment is an important carrier of phosphorus(P)in waters.It is of great importance to investigate the effects of sediment characteristics on P adsorption as it will help understanding the transport process of P in waters.A series of constant temperature oscillation experiments were conducted based on on-site sediment collected from Jiangsu coastal shoals,the equilibrium P adsorption capacities of sediment with different median particle sizes and clay contents,and the solid concentration effects of coarse and fine sediment were studied.The results show that clay content is the key factor on the P adsorption capacity of sediment.Under the same median particle size,sediment with higher clay content has stronger P adsorbability.Therefore,it is more accurate to establish the equation of P adsorption using clay content as the variable instead of the median particle sizes.The solid concentration effect will lead to the decrease of P adsorption capacity with per unit mass of either coarse or fine sediment,although there is a difference in the response trend between the two different sediment particles when the sediment concentration ranges from 0.5 to 2.5 g/L.