温度对泥沙吸附磷的影响研究
2021-07-15张潆元陈迪勇赵亚丽宋光林张颖
张潆元 陈迪勇 赵亚丽 宋光林 张颖



摘 要:磷是持续恶化的水体富营养化主要的限制因子,极易吸附在泥沙颗粒上。因此,研究泥沙对磷的吸附律,对于水体富营养化的防控和治理具有重要意义。通过单因子控制变量法,开展了不同反应温度条件下泥沙对磷的吸附特性的影响试验。结果显示,反应温度的升高有利于吸附反应的进行;准二级动力学方程能较好地描述与不同温度下泥沙对磷的吸附过程,吸附速率在反应开始时较大,随着时间的推移逐渐减小;Langmuir方程能较好地描述泥沙对磷的等温吸附行为,最大吸附量(Qm)随着反应温度的升高而增加;吸附过程中ΔG°<0、ΔH°>0以及ΔS°>0,说明所涉及的化学吸附过程为自发吸热反应。
关键词:泥沙;磷;吸附;温度
中图分类号 X524文献标识码 A文章编号 1007-7731(2021)11-0150-03
Effects of Reaction Temperature on Phosphorus Adsorption Properties in Sediment
ZHANG Luyuan et al.
(Guizhou Institute of Analysis and Testing, Guiyang 550014, China)
Abstract: Phosphorus is the main limiting factor for the water eutrophication and has a strong affinity with sediment. Therefore,studying on the adsorption law of sediment phosphorus is of great significance to the prevention and treatment of water eutrophication. This paper adopts single factor control experiment to analyse the effects of reaction temperature on the adsorption characteristics of sediment phosphorus. Experiments show that the increase of temperature was beneficial to the adsorption of phosphorus in sediment. The dynamic process of the adsorption at different temperature fitted a pseudo second-order reaction kinetic equation. The curves adsorption isotherms were well described by the Langmuir equation. The maximum adsorption capacity (Qm) in the adsorption equation increased with the increase of the reaction temperature. Thermodynamic calculation results were the ΔG°<0, ΔH°>0 and ΔS°>0 ,which showed that phosphorus adsorption onto sediment was an endothermic process.
Key words: Sediment; Phosphorus; Adsorption; Temperature
水體富营养化轻则使水体变质,产生难闻的恶臭气味,严重时导致藻类疯长,产生大面积水华,对国家的经济发展、水生生态环境以及饮用水安全带来威胁。当前研究者普遍认为,水体中不同赋存形态的磷是富营养化的主要限制因子,并且磷与泥沙有着很强的亲和力[1],泥沙对磷的吸附过程会降低水中磷的浓度,对水体的溶解态磷起到“汇”的作用[2]。因此,对于多沙水体,水环境中的泥沙对磷的迁移转运有着十分重要的影响。
温度不仅是影响物理、化学反应的重要参数,也是水沙环境研究中的重要因子。温度可以通过影响磷的形态以及泥沙颗粒的表面电荷、磷与颗粒表面的亲和力等,间接地对水中的溶解态磷吸附转移到泥沙颗粒表面的过程带来影响。本研……
