Zhu Hao, Lin Wenhui, Fan Liwen
Department of Stomatology, General Hospital of Northern Theater Command, Shenyang 110016, China.
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
ACS Omega. 2023 Sep 22;8(39):35893-35903. doi: 10.1021/acsomega.3c03590. eCollection 2023 Oct 3.
This study focuses on the hydrothermal synthesis of magnetically activated carbon and its efficacy in As(III) adsorption. The successful incorporation of magnetite nanoparticles within the porous carbon structure was confirmed, enriching the adsorbent's properties. Comprehensive characterization was performed to analyze the pore size distribution, zeta potential at varying pH levels, and thermostability using thermogravimetric analysis. These adsorbents exhibited high As(III) removal efficiency with a uniform pore distribution. The zeta potentials were observed to decrease with an increase in pH, suggesting a relationship between adsorbent charge and pH. Adsorption dynamics were rigorously modeled using pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models for different adsorbents labeled as , and . Each adsorbent displayed unique fitted parameters, revealing varied adsorption capabilities. The study further explored the adsorption kinetics and found that the pseudo-second-order kinetics model and the Langmuir model were most appropriate for describing the adsorption process. Adsorption thermodynamics was also fitted to elucidate the underlying adsorption mechanisms. For the , and adsorbents, the pseudo-first-order model, the values for the four adsorbents were 434.2, 418.4, 283.5, and 279.5 μg/g, respectively. Take adsorbent as an example; the values for 298, 303, 308, and 313 K were 702, 673, 605, and 589 μg/g, respectively, and values of these temperatures were 0.021, 0.031, 0.018, and 0.009 L/μg, respectively. For the Langmuir model, the values at the four temperatures were 0.999, 0.978, 0.985, and 0.993, respectively, which indicated that the Langmuir model showed higher fitness. For the Freundlich model, the values (L/μg) at the parameters of these temperatures are 432, 409, 328, and 294, respectively. For the Freundlich model, the 1/ values at temperatures of 298, 303, 308, and 313 K are 0.049, 0.045, 0.052, and 0.035, respectively. For the Freundlich model, the values at parameters of 298, 303, 308, and 313 K are 0.986, 0.989, 0.982, and 0.872, respectively. For the Temkin model, the values (in J/mol) are 30.93, 0.894, 0.824, and 0.782 at these temperatures, respectively. The values (in L/μg) are 1.02 × 10, 0.07 × 10, 0.003 × 10, and 0.002 × 10, respectively. The values are 0.973, 0.958, 0.972, and 0.894, respectively. In the end, the Δ, Δ, and Δ values for different adsorbents were calculated. Collectively, these findings contribute significant insights into the design and application of magnetically activated carbon adsorbents for effective As(III) removal.
本研究聚焦于磁性活性炭的水热合成及其对As(III)的吸附效果。证实了磁铁矿纳米颗粒成功掺入多孔碳结构中，丰富了吸附剂的性能。进行了全面表征，以分析孔径分布、不同pH值下的zeta电位，并使用热重分析研究热稳定性。这些吸附剂表现出高As(III)去除效率且孔径分布均匀。观察到zeta电位随pH值升高而降低，表明吸附剂电荷与pH值之间存在关系。使用伪一级、伪二级、Elovich和颗粒内扩散模型对标记为 、 和 的不同吸附剂的吸附动力学进行了严格建模。每种吸附剂都显示出独特的拟合参数，揭示了不同的吸附能力。该研究进一步探讨了吸附动力学，发现伪二级动力学模型和Langmuir模型最适合描述吸附过程。还拟合了吸附热力学以阐明潜在的吸附机制。对于 、 和 吸附剂，伪一级模型中，四种吸附剂的 值分别为434.2、418.4、283.5和279.5 μg/g。以吸附剂 为例；298、303、308和313 K时的 值分别为702、673、605和589 μg/g，这些温度下的 值分别为0.021、0.031、0.018和0.009 L/μg。对于Langmuir模型，四个温度下的 值分别为0.999、0.978、0.985和0.993，这表明Langmuir模型拟合度更高。对于Freundlich模型，这些温度参数下的 值（L/μg）分别为432、409、328和294。对于Freundlich模型，298、303、308和313 K温度下的1/ 值分别为0.049、0.045、0.052和0.035。对于Freundlich模型，298、303、308和313 K参数下的 值分别为0.986、0.989、0.982和0.872。对于Temkin模型，这些温度下的 值（J/mol）分别为30.93、0.894、0.824和0.782。 值（L/μg）分别为1.02×10、0.07×10、0.003×10和0.002×10。 值分别为0.973、0.958、0.972和0.894。最后，计算了不同吸附剂的Δ、Δ和Δ值。总体而言，这些发现为设计和应用磁性活性炭吸附剂以有效去除As(III)提供了重要见解。
