高效去除Cd2+介孔硅酸钙的制备优化及表征

为了进一步研制高效、廉价的Cd²⁺吸附剂，从介孔硅酸钙（CSH）的制备与优化出发，选择钙硅比（Ca/Si）、表面活性剂种类及其用量为因素，采用正交试验探讨CSH的最优制备条件，并结合扫描电镜（SEM）、红外光谱（FTIR）、比表面积测试（BET）、X-射线衍射分析（XRD），对CSH的结构形貌、材料性能进行评价.结果表明，各因素对合成材料吸附性能的影响顺序为：表面活性剂种类 > 表面活性剂用量 > Ca/Si；最优制备条件为：Ca/Si=1：1，以聚乙二醇（PEG）为表面活性剂，表面活性剂添加量为2%；表面活性剂的添加能显著提高材料的吸附性能，最优条件下制备的介孔硅酸钙对Cd²⁺的饱和吸附容量高达687.71 mg·g^-1，吸附等温线符合Langmiur模型；合成的水化硅酸钙为介孔结构，为狭缝孔，呈纳米花状，比表面积为333.47 m²·g^-1，BJH孔径为10.9 nm，孔隙度为2.199 cm³·g^-1；巨大的比表面积、高孔隙度、表面丰富的活性—OH及材料富含可交换态Ca²⁺，以及能与Cd²⁺发生吸附沉淀、表面络合和离子交换，致使其具有优异的吸附性能，有望为Cd²⁺污染水体治理和土壤修复提供潜在优势新材料.

Preparation optimization and characterization of highly efficient removal of Cd2+ mesoporous calcium silicate

In order to further develop a cheap and efficient Cd²⁺ adsorbent, starting from the preparation and optimization of mesoporous calcium silicate (CSH), the choice of calcium silicon ratio (Ca/Si), surfactant kinds and dosage of factors, using the orthogonal experiment to explore the optimal preparation conditions, and combined with scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), specific surface area test (BET), X-ray diffraction analysis (XRD) to evaluate its structural morphology, material performance. The results showed that the order of influence of various factors on the adsorption performance of the synthetic materials was as follows:dispersant type > dispersant dosage > Ca/Si, the optimal preparation conditions were:Ca/Si 1:1, polyethylene glycol (PEG) as the surfactant, 2% addition; the addition of surfactant can significantly improve the adsorption performance of the materials. The saturated adsorption capacity of the prepared mesoporous calcium silicate to Cd²⁺ is up to 687.71 mg·g^-1 under the optimal conditions, and the adsorption isotherm conforms to the Langmiur adsorption model. The synthesized hydrated calcium silicate is mesoporous structure, slit hole and nanofilament, with a specific surface area of 333.47 m²·g^-1, BJH pore diameter of 10.9 nm and porosity of 2.199 cm³·g^-1. Large specific surface area, abundant active -OH on the surface, and abundant exchangeable Ca²⁺ in the material can induce adsorption precipitation, surface complexation and ion exchange with Cd²⁺, leading to its excellent adsorption performance, so as to provide new materials with potential advantages for Cd²⁺ contaminated soil remediation.