阿拉尔河下游沉积物对铀的动态吸附机制

摘要

采用动态吸附法,研究流速、沉积物粒径、沉积物投加量、铀初始浓度等对阿拉尔河下游沉积物吸附铀的影响,并结合Thomas模型及表征数据对吸附机理进行探讨.结果表明,动态吸附饱和时间与流速、沉积物粒径及铀初始浓度呈反相关,与沉积物投加量呈正相关.总饱和吸附量与流速及沉积物粒径呈反相关,与沉积物投加量及铀初始浓度呈正相关.沉积物对铀的动态吸附符合Thomas模型,吸附过程由多个步骤共同控制,吸附速率受多个因素的共同影响.吸附的主要机制为表面络合反应,并伴有离子交换作用.%The adsorption of uranium on sediments from the Lower Alar River was investigated by dynamic adsorption method. The effects of flow rate, sediment particle size, sediment dosage and initial concentration of uranium was studied. The adsorption curve was established by combining the Thomas model in order to explore adsorption mechanism. The results show that the dynamic adsorption saturation time is negatively correlated with the flow rate of the solution, the particle size of the sediments and the initial concentration of uranium, and positively correlated with the sediment dosage. The total saturated adsorption capacity is inversely related to the flow rate of the solution and the particle size of the sediments, which is positively correlated with the sediment dosage and the initial concentration of uranium. The dynamic adsorption of uranium in sediments is in accordance with the Thomas model. The adsorption process is controlled by multiple steps, and the adsorption rate is influenced by many factors. The main mechanism of adsorption is surface complexation reaction, and together with the effect of ion exchange.