Firpo Guadalupe, Vaschetti Virginia M, González Mercado Griselda V, Guerrero Pablo A, Piccioni Martín N, Macaño Héctor R, Dalmasso Pablo R
Centro de Investigación y Transferencia en Ingeniería Química Ambiental (CIQA), Departamento de Ingeniería Química, Facultad Regional Córdoba, Universidad Tecnológica Nacional, Maestro López esq. Cruz Roja Argentina, X5016ZAA, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB, Buenos Aires, Argentina.
Centro de Investigación y Transferencia en Ingeniería Química Ambiental (CIQA), Departamento de Ingeniería Química, Facultad Regional Córdoba, Universidad Tecnológica Nacional, Maestro López esq. Cruz Roja Argentina, X5016ZAA, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB, Buenos Aires, Argentina.
Environ Res. 2025 Aug 1;278:121655. doi: 10.1016/j.envres.2025.121655. Epub 2025 Apr 19.
Emerging contaminants are a group of chemicals that have the potential to enter the environment and cause potentially adverse effects on the ecosystems and their components. Currently, the interest in achieving the removal of emerging contaminants from water bodies and wastewater has grown considerably, which is reflected in several publications on the synthesis of nanomaterials capable of adsorbing them. Among emerging pollutants, methylene blue (MB) is a widely used model dye for the study of adsorption processes on nanomaterials. In this work, we report a facile and greener one-pot synthesis of SiO nanoparticles (SiONPs) than the classical Stöber method, involving a cheaper Si source than TEOS, only water as solvent, and shorter reaction times under neutral conditions at room temperature, i.e. a new sol-gel strategy with favorable greenness attributes. A multi-technical characterization of SiONPs (XRD, FTIR, UV-vis DR, TEM, SEM, EDX, Z-potential, and N adsorption-desorption isotherms at 77 K) confirmed the formation of spherical NPs, with amorphous and polydisperse nature, negatively charged surface, and mesoporous structure. Several batch adsorption experiments of MB were performed by varying pH, contact time, model dye concentration, and SiONPs dosage, and the kinetic and thermodynamic behavior of the removal reaction was elucidated. It was determined that the adsorption process followed a pseudo-second-order kinetic model and a Langmuir isotherm model. SiONPs showed high efficiency towards MB removal after 30 min of contact time (maximum adsorption capacity = 165.6 mg g) and high reusability for up to seven cycles without appreciable loss of adsorption efficiency. In addition, this work reports the first successful application of SiONPs as a cationic dye nanoadsorbent under simulated conditions of real textile wastewater (high pH, very high concentration of MB and dissolved salts, and high COD), proving that NPs are suitable for conditioning water resources contaminated with industrial dyes.
新兴污染物是一类有可能进入环境并对生态系统及其组成部分造成潜在不利影响的化学物质。目前，从水体和废水中去除新兴污染物的研究兴趣大幅增长，这在几篇关于能够吸附它们的纳米材料合成的出版物中有所体现。在新兴污染物中，亚甲基蓝（MB）是用于研究纳米材料吸附过程的一种广泛使用 的模型染料。在这项工作中，我们报告了一种比经典的斯托伯方法更简便、更环保的一锅法合成SiO纳米颗粒（SiONPs），该方法使用比TEOS更便宜的硅源，仅用水作为溶剂，在室温中性条件下反应时间更短，即一种具有良好绿色属性的新型溶胶 - 凝胶策略。对SiONPs进行的多技术表征（XRD、FTIR、UV - vis DR、TEM、SEM、EDX、Z - 电位以及77 K下的N吸附 - 解吸等温线）证实形成了球形纳米颗粒，具有无定形和多分散性质、带负电荷的表面以及介孔结构。通过改变pH值、接触时间、模型染料浓度和SiONPs用量进行了多项MB的批量吸附实验，并阐明了去除反应的动力学和热力学行为。结果表明，吸附过程遵循准二级动力学模型和朗缪尔等温线模型。接触30分钟后，SiONPs对MB的去除效率很高（最大吸附容量 = 165.6 mg/g），并且具有高达七个循环的高可重复使用性，吸附效率没有明显损失。此外，这项工作首次报道了SiONPs在模拟实际纺织废水条件下（高pH值、非常高的MB和溶解盐浓度以及高COD）作为阳离子染料纳米吸附剂的成功应用，证明了纳米颗粒适用于处理受工业染料污染的水资源。
