改性酵母载纳米铁对水中甲基橙的吸附性能研究

Adsorption Property of Modified Yeast Supported Iron Nanoparticles Against Methyl Orange in Water

以改性酵母为载体、烟叶提取液为还原剂,制备了改性酵母载纳米铁(Fe NPs/SC M),并将其用于去除水中甲基橙,通过考察初始pH值、Fe NPs/SC M投加量、甲基橙初始浓度、温度、无机阴离子等对甲基橙去除率的影响,研究其对甲基橙的吸附性能,同时对其吸附动力学、等温吸附模型及吸附热力学进行了探究。结果表明:初始pH值为4.0~9.0时对甲基橙去除率的影响较小,甲基橙去除率随Fe NPs/SC M投加量的增加而升高,随甲基橙初始浓度的增加和温度的升高而降低;无机阴离子会降低甲基橙去除率,其影响大小为:HCO_(3)^(-)>SO_(-4)^(2)>HPO_(4)^(2-)>NO_(3)^(-)>Cl^(-);在30℃、pH值为6.3的条件下,5.0 g·L^(-1) Fe NPs/SC M对50 mg·L^(-1)甲基橙的去除率和去除量(以纯铁计)分别为93.50%±0.38%和523 mg·g^(-1),解吸率仅为1.64%±0.02%。Fe NPs/SC M吸附甲基橙的行为符合准二级动力学方程和Freundlich等温吸附模型。

We prepared modified yeast supported iron nanoparticles(Fe NPs/SC M)by using modified yeast as a carrier and tobacco leaf extract as a reducing agent,and adopted to removing Methyl Orange(MO)in water.Moveover,we studied the adsorption property of Fe NPs/SC M against MO by investigating the effects of initial pH value,Fe NPs/SC M dosage,initial MO concentration,temperature,and inorganic anions on the removal rate of MO.Furthermore,we investigated the adsorption kinetics,isothermal adsorption model,and adsorption thermodynamics.The results show that the initial pH value has little impact on the removal rate of MO within the range of 4.0-9.0;the removal rate of MO increases with the increase of Fe NPs/SC M dosage,and decreases with the increase of the initial MO concentration and temperature;inorganic anions can reduce the removal rate of MO in the following order:HCO_(3)^(-)>SO_(-4)^(2)>HPO_(4)^(2-)>NO_(3)^(-)>Cl^(-).Under the conditions of 30℃,pH value of 6.3,the removal rate and removal amount(calculated as pure Fe)of 50 mg·L^(-1) MO by 5.0 g·L^(-1) Fe NPs/SC M are 93.50%±0.38%and 523 mg·g^(-1),respectively,and the desorption rate is only 1.64%±0.02%.The adsorption behavior of MO on Fe NPs/SC M conforms to the pseudo-second-order kinetic equation and the Freundlich isothermal adsorption model.