Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, 19 Le Thanh Tong, Hoan Kiem, Hanoi, 100000, Viet Nam.
HUS High School for Gifted Students, University of Science, Vietnam National University, Hanoi, 182 Luong the Vinh, Thanh Xuan, Hanoi, 100000, Viet Nam.
Chemosphere. 2022 Nov;307(Pt 2):135856. doi: 10.1016/j.chemosphere.2022.135856. Epub 2022 Aug 6.
The present study aims to investigate adsorption characteristics and mechanisms of Moringa (MO) seeds protein on nanosilica rice husk and their applications in removal of pharmaceutical residues including the fluoroquinolone antibiotic levofloxacin (LFX) and the nonsteroidal anti-inflammatory drug diclofenac (DCF) in aquatic environment. Molecular weight of MO protein was determined by gel-permeation chromatography (GPC) method while its amino acids were quantified by high performance liquid chromatography (HPLC). The number-(M) and weight-average molecular weights (M) of MO protein were 1.53 × 10 and 1.61 × 10 g/mol, respectively. Different effective conditions on adsorption protein on nanosilica including contact time, pH, adsorbent dosage, and ionic strength were systematically optimized and found to be 180 min, 10, 10 mg/mL and 1 mM KCl, respectively. The surface charge change by zeta potential, surface modification by Fourier-transform infrared spectroscopy (FT-IR) and adsorption isotherms demonstrated that protein adsorption on nanosilica was governed by both electrostatic and non-electrostatic interactions. Application of protein functionalized nanosilica (ProFNS) in LFX and DCF removal were also thoroughly studied. The selected conditions for LFX and DCF removal using ProFNS were 1 mM KCl for both LFX and DCF; pH 8 and pH 6; contact time 90 and 120 min, and adsorption dosage 10 and 5 mg/ml for LFX and DCF, respectively. Adsorption isotherms of protein on nanosilica as well as LFX and DCF onto ProFNS at different ionic strengths were reasonably fitted by the two-step model while a pseudo-second-order model could fit adsorption kinetic well. The removal of LFX and DCF using ProFNS significantly increased from 51.51% to 87.35%, and 7.97%-50.02%, respectively. High adsorption capacities of 75.75 mg/g for LFX and 59.52 mg/g for DCF, indicate that ProFNS is a great performance for pharmaceutical residues removal in water environment.
本研究旨在探讨 Moringa（MO）种子蛋白在纳米硅质稻壳上的吸附特性和机制及其在去除水环境中药物残留方面的应用，包括氟喹诺酮类抗生素左氧氟沙星（LFX）和非甾体抗炎药双氯芬酸（DCF）。MO 蛋白的分子量通过凝胶渗透色谱（GPC）法测定，其氨基酸含量通过高效液相色谱（HPLC）定量。MO 蛋白的数均分子量（M）和重均分子量（Mw）分别为 1.53×10 和 1.61×10 g/mol。系统优化了吸附蛋白在纳米硅质稻壳上的不同有效条件，包括接触时间、pH 值、吸附剂用量和离子强度，分别为 180 min、10、10 mg/mL 和 1 mM KCl。通过zeta 电位的表面电荷变化、傅里叶变换红外光谱（FT-IR）的表面修饰和吸附等温线证明，蛋白质在纳米硅质稻壳上的吸附受静电和非静电相互作用的共同控制。还深入研究了蛋白质功能化纳米硅质稻壳（ProFNS）在 LFX 和 DCF 去除中的应用。使用 ProFNS 去除 LFX 和 DCF 的选定条件分别为：LFX 和 DCF 均为 1 mM KCl；pH 8 和 pH 6；接触时间分别为 90 和 120 min，吸附剂用量分别为 10 和 5 mg/ml。在不同离子强度下，蛋白质在纳米硅质稻壳上以及 LFX 和 DCF 吸附到 ProFNS 上的吸附等温线均由两步模型合理拟合，而伪二阶模型可以很好地拟合吸附动力学。使用 ProFNS 去除 LFX 和 DCF 的效果显著提高，分别从 51.51%增加到 87.35%和从 7.97%增加到 50.02%。LFX 的吸附容量高达 75.75 mg/g，DCF 的吸附容量为 59.52 mg/g，表明 ProFNS 是一种用于水环境中药物残留去除的高效材料。
