氯化铁改性活性氧化铝的制备和表征及其除磷效果研究

为提高活性氧化铝对废水中磷的去除效果,以氯化铁为改性剂,采用碱性沉积法对其进行改性,测定了改性前后活性氧化铝的比表面积及孔容,考察了吸附时间、pH值、废水初始浓度、改性剂投加量等因素对去除废水中磷的影响,探讨了改性活性氧化铝对磷的吸附机理。结果表明,改性后活性氧化铝的比表面积为430.582 m2/g,提高了23.5%;吸附时间为4 h时,吸附达到平衡,磷吸附量比改性前提高了10.2%;当pH值在5~7时,磷去除效果最好;随着废水中磷初始浓度的提高,磷去除率降低;随着改性活性氧化铝投加量的增加,磷去除率升高,当投加量为5.0g/L时,吸附效果最好;Freundlich和Langmuir 2种等温线模型均能较好反映改性活性氧化铝对磷的吸附行为,其中Langmuir模型更为理想。

Behavior of Phosphorus Adsorption from Aqueous Solutions on Modified Activated Alumina

In order to improve activated alumina’s performance of phosphorus removal in waste water,the activated alumina as a carrier was modified with ferric chloride solution by the alkaline deposition method.Pore volume and BET surface area were determined.The effects of adsorption time,pH value,initial concentration of wastewater,modified dosage and other factors on the impact of phosphorus removal from wastewater were studied.Modified activated alumina’s adsorption mechanism of phosphorus was discussed.The results showed that the specific surface area of modified activated alumina was 430.582 m2/g and improved by 23.5% than the unmodified activated alumina’s.It came to the adsorption equilibrium after four hours and the adsorption capacity of phosphorus improved by 10.2%.The best adsorption pH value was 5~7.It was also found that with the increase of initial concentration of wastewater,the removal rate of phosphorus decreased instead,while the removal rate of phosphorus increased with the increasing modified dosage,the optimal dosage of modified activated alumina was 5.0 g/L.Both Freundlich and Langmuir model of adsorption isotherms could reflect the adsorption behavior of modified activated alumina for phosphorus,while the Langmuir model was more proper.