School of Resource and Environmental Science, South-Central Minzu University, Wuhan 430074, China; Engineering Research Center for Heavy Metal Pollution Control of Hubei Province, Wuhan 430074, China.
School of Resource and Environmental Science, South-Central Minzu University, Wuhan 430074, China; Engineering Research Center for Heavy Metal Pollution Control of Hubei Province, Wuhan 430074, China.
Sci Total Environ. 2022 Aug 10;833:154858. doi: 10.1016/j.scitotenv.2022.154858. Epub 2022 Mar 26.
Mesoporous silica (MCM-41) is widely used as a supporting material due to its large specific surface area and good stability, but it cannot remove heavy metals due to the lack of adsorption active sites. In this study, the MCM-41 (a mesoporous SiO material) decorated with iron and magnesium oxide (Fe/Mg-MCM-41) was found to be an excellent adsorbent to remove arsenic(V) from water. FTIR, BET, TEM-EDS, XRD, XPS, etc. were applied for characterization analysis. Adsorption isotherms were fitted well by the Langmuir model and the experimental maximum adsorption capacity of Fe/Mg-MCM-41 (magnesium accounts for 4%) was 71.53 mg/g at pH = 3. Thermodynamics analysis suggested exothermic nature of adsorption behavior. Kinetic process was well described by the pseudo-second-order model and adsorption rate was controlled by intraparticle diffusion and film diffusion. Moreover, the adsorption behavior of As(V) onto Fe/Mg-MCM-41 was investigated under different reaction conditions, such as pH, temperature, Mg-doping and competing ions. The results showed that loading a certain amount of magnesium can significantly improve arsenic removal efficiency. Additionally, Fe/Mg-MCM-41 exhibits high arsenic(V) removal in the wide pH range of 3-10. The Fe/Mg-MCM-41 can be regenerated and used after four consecutive cycles. The high arsenic(V) sorption capacity, wide range of pH applications, ability to regenerate, and reusability of Fe/Mg-MCM-41 confirmed that this adsorbent is promising for treating As-contaminated wastewater.
介孔硅（MCM-41）由于其较大的比表面积和良好的稳定性而被广泛用作支撑材料，但由于缺乏吸附活性位，它不能去除重金属。在这项研究中，发现负载铁和氧化镁的 MCM-41（介孔 SiO 材料）（Fe/Mg-MCM-41）是一种从水中去除砷（V）的优良吸附剂。采用 FTIR、BET、TEM-EDS、XRD、XPS 等进行了表征分析。吸附等温线通过 Langmuir 模型拟合良好，Fe/Mg-MCM-41（镁占 4%）的实验最大吸附容量为 71.53mg/g，pH=3。热力学分析表明吸附行为是放热的。动力学过程很好地由伪二阶模型描述，吸附速率受内扩散和膜扩散控制。此外，还研究了不同反应条件下（如 pH、温度、镁掺杂和竞争离子），As(V)在 Fe/Mg-MCM-41 上的吸附行为。结果表明，负载一定量的镁可以显著提高砷的去除效率。此外，Fe/Mg-MCM-41 在 3-10 的宽 pH 范围内具有较高的砷（V）去除率。Fe/Mg-MCM-41 可以在经过四个连续循环后再生和重复使用。Fe/Mg-MCM-41 具有高砷（V）吸附容量、宽 pH 应用范围、再生能力和可重复使用性，证实了这种吸附剂在处理含砷废水方面具有广阔的应用前景。
