Characteristics of Adsorption of Ammonia Nitrogen and Phosphate by Sediments in the Songhua River

摘要

The characteristics of adsorption of ammonia nitrogen and phosphate by sediments in the Songhua River are investigated.These include isothermal adsorption,adsorption kinetics,the effect of pH and temperature on adsorption.The results are as follows:With an increase of balance concentration,both the adsorption capacity of ammonia nitrogen and phosphate in sediment increase.And adsorption capacity of ammonia nitrogen in sediments has a relative linear relationship with balance concentrations on the tested range.Both the kinetics of ammonia nitrogen and phosphate adsorption exhibit a complex behavior,the fast adsorption process last 1 hour,and then reach the dynamic adsorption equilibrium.With an increase of the pH value,the adsorption capacity of ammonia nitrogen in sediment increases,but adsorption capacity of phosphate decreases.Increasing temperature will restrain the adsorption of ammonia nitrogen,promote the adsorption of phosphorus,instead.%为了探讨松花江哈尔滨段河道底泥底泥对氨氮和磷的吸附特性,本文分别从等温吸附、动力学吸附、改变pH值和温度四个方面进行了研究.结果表明:在实验浓度范围内,底泥对氨氮和磷的吸附量均随着平衡浓度的增大而增大,且氨氮的吸附量与平衡浓度呈线性关系.底泥对氨氮和磷的吸附是一个复合动力学过程,均在lh内快速进行,之后基本处于一种动态吸附平衡.氨氮吸附量随pH值的升高而增加,而磷吸附量则随pH值的升高而降低.在试验温度范围内,温度升高会抑制底泥对氨氮的吸附,促进底泥对而磷的吸附.