Abstract:

Ternary(Fe-Mg-Al) layered hydroxides,n (Fe):n (Mg):n(Al)=1:1:1 has been synthesized by coprecipita- tion method. Its adsorption capacity for phosphorus is studied,and the influences of adsorption time,temperature,pH and other factors on the adsorption effect are investigated. The results show that its adsorption capacity for phosphorus increases dramatically in the first 20 min,but 40 min later becomes stable. When its dosage is 1.0 g/L,both of the adsorbing rate and adsorption capacity are relatively high. Its initial pH value is in the range of 3 to 10,having no significant influence on the adsorption effect. Temperature has greater effect on the adsorption effect. The adsorption capacity increases with the increase of temperature. It indicates that the adsorption process is an endothermic process. The correlation coefficient of isothermal adsorption data of such hydrotalcite and Langmuir equation is very high. When the temperature is 45℃,the maximum adsorption capacity can reach 13.15 mg/g,while the adsorption process is in line with second order kinetics mod.

Key words: Fe-Mg-Al, hydrotalcite, phosphorus, adsorption

摘要：

采用低饱和共沉淀的方法合成了n(Fe):n(Mg):n(Al)=1:1:1的铁镁铝三元类水滑石。研究其对磷的吸附特性,考察了吸附时间、投加量、温度、pH等因素对吸附效果的影响。结果表明:此类水滑石对磷的吸附在前20 min吸附量急剧增加,40 min之后趋于稳定;当投加量为1.0 g/L时,吸附率和吸附容量都相对较高;初始pH为3～10时,对吸附效果无明显影响;温度对吸附效果影响较大,温度升高吸附量增加,表明此吸附过程是吸热过程。此类水滑石对磷的等温吸附数据与Langmuir方程的相关系数很高,45℃时饱和吸附量高达13.15 mg/g,同时吸附过程符合二级动力学模型。

关键词: 铁镁铝, 水滑石, 磷, 吸附

CLC Number: 

• X703.1