Nano silica (nSiO₂), induces potential harmful effects on the living environment and human health. It is well established that SiO₂ facilitates the co-transport of a variety of other contaminants, including heavy metals and pesticides. The current study focused on the systematic evaluation of the effects of multiple physicochemical parameters such as pH (5, 7, and 9), ionic strength (10, 50, and 100 mM), and humic acid (0.1, 1, and 10 mg/L) on the transport and retention of nSiO₂ in saturated porous medium. Additionally, the influent concentration of nSiO₂ (10, 50, and 100 mg/L) was also varied. Our experimental findings indicate that the size of nSiO₂ aggregates was directly related to the pH, ionic strength, HA, and particle concentration had a significant impact on the breakthrough curves (BTCs). The stability provided by the varying concentrations of pH and humic acid had a significant effect on the size of nSiO₂ aggregates and transport (C/C₀ > 0.7). The presence of a greater magnitude of negative charge on the surface of both nSiO₂ and quartz sand resulted in less aggregation and enhanced flow of nSiO₂ through the sand column. The Electrostatic and steric repulsion forces were the primary governing mechanisms in relation to the size of nSiO₂ aggregates, affecting the single-collector efficiency and attachment efficiency, which determined the maximal transport of nSiO₂. Conversely, a probable increase in Van der Waals force of attraction exacerbated the particle deposition and reduced their mobility for high ionic strength, and particle concentrations (C/C₀ < 0.1). The formation of large nSiO₂ aggregates, in particular, was principally responsible for the enhancement of nSiO₂ retention in sand columns over a broad range of IS and particle concentration. The interaction energy profiles based on the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory were determined to understand the mechanism of nSiO₂ deposition. Aditionally, all the experimental BTCs were mathematically simulated and justified by the colloidal filtration theory (CFT). Considering the environmental ramifications, the transport behavior of nSiO₂ was further evaluated in various natural matrices such as river, lake, ground, and tap water. The nSiO₂ suspended in the river, lake, and tap water had significantly higher mobility (C/C₀ > 0.7), whereas groundwater indicated higher retention (C/C₀ < 0.3). The study advances our collective knowledge of physicochemical and environmental parameters that can affect particle mobility.

纳米二氧化硅 (nSiO ₂ ) 会对生活环境和人类健康产生潜在的有害影响。众所周知，SiO ₂促进了多种其他污染物的共同运输，包括重金属和杀虫剂。目前的研究侧重于系统评估多种物理化学参数的影响，例如 pH（5、7 和 9）、离子强度（10、50 和 100 mM）和腐殖酸（0.1、1 和 10 mg） /L)关于nSiO ₂在饱和多孔介质中的传输和保留。此外，nSiO ₂的进水浓度（10、50和 100 mg/L）也不同。我们的实验结果表明，nSiO _2的尺寸聚集体与 pH 值、离子强度、HA 直接相关，颗粒浓度对穿透曲线 (BTC) 有显着影响。不同浓度的 pH 值和腐植酸所提供的稳定性对 nSiO ₂聚集体的大小和传输 (C/C ₀  > 0.7) 具有显着影响。nSiO ₂和石英砂表面存在较大量的负电荷导致较少的聚集和增强的nSiO ₂通过砂柱的流动。静电和空间排斥力是与 nSiO _{2尺寸相关的主要控制机制}聚集体，影响单收集效率和附着效率，这决定了 nSiO _{2的最大传输}。相反，范德华引力的可能增加加剧了粒子沉积并降低了它们在高离子强度和粒子浓度（C/C ₀  < 0.1）下的迁移率。尤其是大的 nSiO ₂聚集体的形成，主要负责在广泛的 IS 和颗粒浓度范围内提高砂柱中的 nSiO _2保留。确定了基于 Derjaguin-Landau-Verwey-Overbeek (DLVO) 理论的相互作用能谱，以了解 nSiO _2的机理沉积。此外，所有实验性 BTC 均通过胶体过滤理论 (CFT) 进行数学模拟和证明。_{考虑到环境影响，进一步评估了 nSiO 2}在河流、湖泊、地下水和自来水等各种自然基质中的输运行为。悬浮在河流、湖泊和自来水中的nSiO _{2具有显着更高的流动性（C/C 0}  > 0.7），而地下水具有更高的滞留性（C/C ₀  < 0.3）。该研究提高了我们对可能影响粒子流动性的物理化学和环境参数的集体认识。