Abstract

In this study, nano-silica (NS) was synthesized from barley grass straw through a combination of acid and heat treatments. The synthesized nano-silica was then used as the precursor silica material for the synthesis of nano-zeolite (NZ). NS and NZ were characterized using X-ray fluorescence (XRF), dynamic light scattering (DLS), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Bruner–Emmett–Teller method (BET) measurements. The NS and NZ particles were observed to be hydrophobic and possess large surface areas (128 and 106 m²/g, respectively); this results in high uptake of gasoline compared to other sorbents. NS and NZ particles (0.5 g) were each applied to a 40 mg/g concentration of gasoline-contaminated water at pH 7, which resulted in high uptake efficiencies of 95% for NS and 85% for NZ. Kinetics and equilibrium studies were performed, and the obtained results were processed to produce relevant parameters. The sorption was significantly effective, and the percentage of contaminants removed was seen to depend heavily on the amount of sorbent added. The kinetics results indicated that the second-order sorption kinetics exhibited the best fit for the gasoline sorption data. It was also apparent that the Langmuir isotherms described the sorption the most closely. The results suggest that nanoparticles provide a clean-up solution for petroleum spillage and contamination in water.

摘要

在这项研究中，通过酸和热处理的结合，从大麦草中合成了纳米二氧化硅 (NS)。然后将合成的纳米二氧化硅用作合成纳米沸石 (NZ) 的前体二氧化硅材料。NS 和 NZ 使用 X 射线荧光 (XRF)、动态光散射 (DLS)、扫描电子显微镜 (SEM)、能量色散 X 射线 (EDX) 分析、傅里叶变换红外 (FTIR) 光谱、X-射线衍射（XRD）和布鲁纳-埃米特-泰勒法（BET）测量。观察到 NS 和 NZ 颗粒是疏水的并且具有大的表面积（128 和 106 m ²/g，分别）；与其他吸附剂相比，这导致汽油的高吸收。NS 和 NZ 颗粒 (0.5 g) 分别应用于 40 mg/g 浓度的 pH 值为 7 的汽油污染水中，这导致 NS 的吸收效率为 95%，NZ 的吸收效率为 85%。进行动力学和平衡研究，并对所得结果进行处理以产生相关参数。吸附效果显着，去除污染物的百分比在很大程度上取决于添加的吸附剂的量。动力学结果表明，二级吸附动力学表现出对汽油吸附数据的最佳拟合。很明显，朗缪尔等温线最接近地描述了吸附。