【摘要】 尖晶石型化合物具有强磁性,若用作污水处理材料则易于分离回收;Fe和Mn元素对As具有较强的亲和性,为此,制备了一种同时含有Fe、Mn元素的尖晶石型化合物MnFe2O4,并考察了其对As的吸附特性。结果表明,MnFe2O4能快速吸附去除水体中的As,且吸附态的As可用10%的NaOH溶液快速解吸,前5 min内As的吸附、解吸量分别占平衡吸附和解吸量的60%~80%;在试验条件下,MnFe2O4对As(Ⅴ)和As(Ⅲ)的平衡吸附量均可达到28 mg/g左右,但吸附态的As(Ⅴ)更容易被解吸;As的吸附和解吸过程符合Lagergren二级速率方程。MnFe2O4对As的吸附受pH、温度、离子强度等因素的影响,较低的温度以及较高的离子强度有利于As的吸附,吸附As(Ⅲ)和As(Ⅴ)的最佳pH值分别为(6~9.4)和(8.3~10.3)。更多还原

【Abstract】 Spinel-type compounds have strong magnetism,and they can be separated when being used as wastewater treatment material.Fe and Mn have a strong affinity for As.Therefore,a spinel-type compound containing Fe and Mn(MnFe2O4) was prepared,and its adsorption characteristics of As were investigated.The results show that As can be effectively adsorbed by MnFe2O4,and the adsorbed As can be effectively desorbed by 10% NaOH solution.The adsorption and desorption amounts of As approach 60% to 80% of the equilibrium adsorption and desorption within 5 min.The equilibrium adsorption amounts of As(Ⅴ) and As(Ⅲ) by MnFe2O4 are all about 28 mg/g.The adsorbed As(Ⅴ) is more easily desorbed.The adsorption and desorption processes of As follow Lagergren pseudo-second-order rate equation.The adsorption of As by MnFe2O4 is influenced by pH,temperature and ion strength.The optimal adsorption of As occurs at low temperature,high ion strength,pH 6 to 9.4 for As(Ⅲ) and pH 8.3 to 10.3 for As(Ⅴ).更多还原