This study has dealt with synthesis of doped strontium hexaferrite / zero-valent iron nanocomposite (SrFe12O19/nZVI) and adsorption of Congo Red (CR) dye by the nanocomposite from aqueous solution was evaluated. The adsorbent was characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). Optimization of experimental conditions such as pH, initial concentration of pollutant, adsorbent weight, contact time, and temperature was done. Maximum removal efficiency was achieved at pH of 8.5, initial concentration of CR=20 μg mL-1, adsorbent weight of 0.12 g with 15 min contact time and 25ºC temperature. Langmuir isotherm with R2=0.9959 seems to have best fit to the CR adsorption results. Also, kinetic studies revealed that adsorption of CR was fitted to the pseudo-second-order model with R2=0.9969. In addition, thermodynamic parameters were evaluated.

中文翻译：

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使用掺杂的六铁酸锶 - 零价铁纳米复合材料从水溶液中吸附刚果红：动力学、等温线和热力学研究

本研究涉及掺杂六铁酸锶/零价铁纳米复合材料 (SrFe12O19/nZVI) 的合成，并评估了纳米复合材料从水溶液中吸附刚果红 (CR) 染料。使用傅里叶变换红外光谱 (FT-IR)、X 射线衍射 (XRD) 分析和扫描电子显微镜 (SEM) 对吸附剂进行表征。优化了实验条件，如 pH 值、污染物初始浓度、吸附剂重量、接触时间和温度。在 pH 值为 8.5、CR 初始浓度为 20 μg mL-1、吸附剂重量为 0.12 g、接触时间为 15 分钟和温度为 25ºC 的情况下，去除效率最高。具有 R2=0.9959 的朗缪尔等温线似乎最适合 CR 吸附结果。还，动力学研究表明，CR 的吸附符合伪二级模型，R2=0.9969。此外，还评估了热力学参数。