响应曲面法优化制备改性海泡石负载纳米铁材料的试验研究

Optimal preparation conditions of sepiolite-supported nanoscale iron using response surface methodology

以直接耐晒黑为目标污染物,以FeSO4浓度、KBH4浓度和改性海泡石的投加量为影响因素,应用Box-Behnken响应曲面法进行了三因素三水平试验,优化了以改性海泡石为载体的纳米铁材料的制备方法.结果表明:在所选的试验范围内,FeSO4浓度和KBH4浓度的交互作用对纳米铁材料的制备有显著影响,对其去除直接耐晒黑性能的影响起到了关键性作用,且FeSO4浓度的影响更为显著;而改性海泡石的投加量和KBH4浓度的交互作用不显著.改性海泡石负载纳米铁的最佳制备条件为:0.13mol·L-1的FeSO4溶液50mL,0.18mol·L-1的KBH4溶液50mL,改性海泡石的投加量为2.86g.在此条件下制得的纳米铁材料,其XRD谱图在2θ=44.7°处出现了Fe0的特征衍射吸收峰;对直接耐晒黑处理3h后,直接耐晒黑的去除率可达98.9%,比仅采用改性海泡石的去除率提高了35.7%.

In this study, preparation conditions of sepiolite-supported nanoscale iron were optimized by Box-Behnken response surface methodology. The FeSO4 concentration, KBH4 concentration, and modified sepiolite dosage were chosen as impact factors. The experiments were performed using direct fast black as target pollutant. The results showed that the interaction between FeSO4 and KBH4 concentration on the removal direct fast black by sepiolite-supported nanoscale iron had a significant effect, and FeSO4 concentration was more significant within the selected test range. On the contrary, the interaction between modified sepiolite dosage and KBH4 concentration was not significant. The optimum preparation conditions of sepiolite-supported nanoscale iron were 50 mL FeSO4 with concentration of 0.13 mol·L^-1, 50 mL KBH4 with concentration of 0.18 mol·L^-1, and the sepiolite dosage of 2.86 g. Under the optimum conditions, the removal percentage of direct fast black was 98.9% using sepiolite-supported nanscale iron at 3 h. The removal percentage increased by 35.7% compared with using the modified sepiolite alone. In addition, the sepiolite-supported nanoscale iron had the characteristic diffraction peak of Fe0 detected at 2θ=44.7° in the XRD patterns.