酵母菌载纳米铁去除水中2,4,6–三氯酚的性能

Removal efficiency of 2,4,6-trichlorophenol in water by yeast supported iron nanoparticles

以酵母菌为载体,废弃烟叶提取物为还原剂,制备酵母菌载纳米铁(TB-Fe/SC NPs),并探究其去除水中2,4,6-三氯酚(2,4,6-TCP)的性能。结果表明:负载在酵母菌上的纳米铁为粒径(77.6±16.1)nm的球形颗粒;TB-Fe/SC NPs去除2,4,6-TCP主要包括吸附和氧化降解2种途径,符合拟二级反应动力学模型;溶解氧和羟自由基在TB-Fe/SC NPs氧化降解2,4,6-TCP中起重要作用;TB-Fe/SC NPs对2,4,6-TCP的去除率随温度的升高而增大,随2,4,6-TCP初始浓度的增大而减少,而反应体系的pH值对TB-Fe/SC NPs去除2,4,6-TCP的影响较小;TB-Fe/SC NPs用量为1.0~3.0 g/L时,2,4,6-TCP的去除率随TB-Fe/SC NPs用量的增大而增大;Fe^(3+)、Mg^(2+)、Ca^(2+)和SO_(4)^(2-)能促进TB-Fe/SC NPs去除2,4,6-TCP的反应,HPO_(4)^(2-)、HCO_(3)^(-)和腐殖酸则对反应有抑制作用,而K^(+)、NO_(3)^(-)和Cl^(-)对2,4,6-TCP的去除影响不明显;TB-Fe/SC NPs能在室温下稳定储存6个月以上,重复使用6次后,2,4,6-TCP的去除率由80.54%下降到28.75%;在25℃和pH=5.0的条件下,3 g/L TB-Fe/SC NPs对20 mg/L 2,4,6-TCP的去除率和去除量分别为(80.54±0.39)%、(5.23±0.03)mg/g。

Yeast supported iron nanoparticles(TB-Fe/SC NPs)was prepared by using yeast as carrier and waste tobacco leaf extract as reducing agent.The removal of 2,4,6-trichlorophenol(2,4,6-TCP)by the as-prepared TB-Fe/SC NPs in aqueous solutions was investigated.The results indicated that the iron nanoparticles loaded on the yeast was spherical with a particle size of(77.6±16.1)nm.The removal of 2,4,6-TCP by TB-Fe/SC NPs mainly consisted of two pathways of adsorption and oxidative degradation,and the 2,4,6-TCP removal well follows the pseudo-second order kinetics.Dissolved oxygen and hydroxyl radicals played important roles in the oxidative degradation of 2,4,6-TCP.The removal efficiency of 2,4,6-TCP increased with the increase of temperature,and decreased with the increase of the initial concentration of 2,4,6-TCP,while the solution pH influences the 2,4,6-TCP removal slightly.The removal efficiency of 2,4,6-TCP increased with the increase of TB-Fe/SC NPs at the dosage of 1.0 g/L to 3.0 g/L.Fe^(3+),Mg^(2+),Ca^(2+) and SO_(4)^(2-) exhibits an obvious promoting effects on the removal of 2,4,6-TCP by TB-Fe/SC NPs,HPO_(4)^(2-),HCO_(3)^(-) and humic acid inhibits the removal of 2,4,6-TCP significantly,while K^(+),NO_(3)^(-) and Cl^(-) have no obvious influence on the removal of 2,4,6-TCP.This TB-Fe/SC NPs could be stored stably at room temperature for more than 6 months.The removal efficiency of 2,4,6-TCP decreased from 80.54%to 28.75%after six repeated applications.The removal efficiency and removal amount of 20 mg/L 2,4,6-TCP by 3 g/L TB-Fe/SC NPs were(80.54±0.39)%,(5.23±0.03)mg/g,respectively,at 25℃ and pH=5.0.