This study describes the sustainable and eco-friendly synthesis of the silica-based mesoporous structure from the use of alternative amorphous silica extracted from rice husk ash (RHA). The mesoporous material was called MCM-48 (RHA), and its application as adsorbent to the antimony (Sb) remediation in environmental samples was tested. The adsorbent was prepared by an efficient and sustainable hydrothermal method, which exhibited an amorphous framework with type IV isotherms and type H1 hysteresis, and surface area, total pore volume, and pore diameter values of 820.9 m2 g-1, 0.6 cm3 g-1, and 3.7 nm, respectively. In addition, the MCM-48 (RHA) exhibited a three-dimensional cubic mesostructure (Ia3d space-group symmetry) with a narrow mesopore distribution, uniform spherical particles, and well-defined architecture. Multivariate optimization using a factorial design (24) was employed in the adsorption tests of Sb. The variables evaluated and the optimum conditions obtained were (i) adsorbent mass (45 mg); (ii) adsorption time (115 min); (iii) pH 2; and (iv) Sb initial concentration of 8 mol L-1. In these conditions, we found a maximum adsorption efficiency of Sb in the order of 95%. The adsorbent material proposed in this study proved to be efficient for Sb remediation in water samples under different experimental conditions. A total of five samples were analyzed and Sb concentrations on the order of 8 ppm were added, in which a removal efficiency of Sb raging between 88 and 96% was obtained for the remediation in real samples. In addition, the low cost of the synthesis of MCM-48 (RHA) in combination with its high and fast adsorption capacities offers a great promise for wastewater remediation, which makes it very attractive for environmental approaches.

中文翻译：

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实验设计在优化采用介孔阵列的环境样品中锑 (Sb) 修复程序中的应用。

本研究描述了通过使用从稻壳灰 (RHA) 中提取的替代无定形二氧化硅，可持续且环保地合成二氧化硅基介孔结构。该介孔材料称为MCM-48（RHA），并测试了其作为吸附剂在环境样品中锑（Sb）修复中的应用。该吸附剂采用高效、可持续的水热法制备，呈现出具有IV型等温线和H1型滞后的无定形骨架，其表面积、总孔体积和孔径值分别为820.9 m2 g-1、0.6 cm3 g-1 , 和 3.7 nm, 分别。此外，MCM-48（RHA）呈现出具有窄中孔分布、均匀球形颗粒和明确结构的三维立方介孔结构（Ia3d 空间群对称性）。在 Sb 的吸附测试中采用了使用因子设计 (24) 的多变量优化。评估的变量和获得的最佳条件是 (i) 吸附剂质量 (45 mg)；(ii) 吸附时间（115 分钟）；(iii) pH 值为 2；(iv) Sb 初始浓度为 8 mol L-1。在这些条件下，我们发现 Sb 的最大吸附效率约为 95%。本研究中提出的吸附材料证明在不同实验条件下对水样中的 Sb 修复是有效的。共分析了 5 个样品，并添加了 8 ppm 左右的 Sb 浓度，其中 Sb 的去除效率在 88% 到 96% 之间，用于修复实际样品。此外，