摘要
研究了钢渣和γ-Al2O3对水溶液中磷素的等温吸附特征和吸附动力学过程。考察了初始溶液质量浓度和温度对吸附作用的影响,计算了钢渣和γ-Al2O3对磷素的吸附速率。结果表明:两者均符合Langmuir等温吸附模型,对磷素的最大吸附量:钢渣(0.305 5 mg/g)<γ-Al2O3(0.686 8 mg/g);但缓冲容量:钢渣(0.871 9 L/mg)>γ-Al2O3(0.613 1L/mg),钢渣具有较高的除磷性价比。随着初始溶液质量浓度的增大,钢渣和γ-Al2O3对磷素的平衡吸附量均增大,并显著延长了钢渣达到吸附平衡的时间。温度升高对两者的影响不大,只是显著延长了钢渣达到吸附平衡的时间。温度较高,初始溶液质量浓度较高的条件下,γ-Al2O3的吸附速率较大,有利于吸附作用的进行;相反的条件下,则有利于钢渣吸附作用的进行。钢渣和γ-Al2O3吸附除磷的吸附动力学过程均符合准二级动力学模型,由该模型可以估算出其对水溶液中磷素的平衡吸附量,误差基本在7%以内。
This paper presented a study on the isothermal adsorption characteristics and absorption kinetics process of the steel slag and γ-Al2O3 onto the phosphorus in the water. Phosphorus adsorption isotherm and its kinetics were examined and effects of initial phosphorus concentration and temperature were investigated to reveal reaction mechanisms. Phosphorus adsorption rates of steel slag and γ-Al2O3 under different conditions were cal- culated for comparison. The results showed that Langmuir isotherm is found to fit the data of phosphorus adsorption of steel slag and γ-Al2O3 well. The phosphorus adsorption capacity was that steel slag （0.305 5 mg/g）, which was smaller than γ-Al2O3 （0.686 8 mg/g） ;while steel slag had the buffer capacity of 0.871 9 L/mg, which was more than γ-Al2O3 （0.613 1 L/mg）. Accordingly, the steel slag has higher phosphorus removal performance-cost ratio. With the increase of initial phosphorus concentration, both steel slag and γ-Al2O3 would increase their e- quilibrium amounts of phosphorus adsorption. Meanwhile, it could significantly last the time of adsorption equilibrium of steel slag. The influence of temperature on them was not significant, since it could only prolong the time of adsorption equilibrium of steel slag. Under the condition of higher temperature and higher initial phos- phorus concentration, γ-Al2O3 would have larger adsorption rate, which was beneficial for adsorption. On the contrary, it would be conducive to the steel slag. The change of phosphorus concentration with time about steel slag and γ-Al2O3 can be both described by the pseudo second-order kinetics with correlation coefficient of 0.97. Accordingly, amounts of phosphorus adsorbed at equilibrium can be calculated with error below 7%.
出处
《苏州科技学院学报（工程技术版）》
CAS
2014年第1期10-15,共6页
Journal of Suzhou University of Science and Technology （Engineering and Technology）
基金
江苏省优势学科建设项目
