Hazardous Air Pollutants Laboratory, Pakistan Institute of Engineering & Applied Sciences, Islamabad, Pakistan; Department of Chemistry, Hazara University, Mansehra, Pakistan.
Hazardous Air Pollutants Laboratory, Pakistan Institute of Engineering & Applied Sciences, Islamabad, Pakistan.
Environ Res. 2023 Dec 1;238(Pt 1):117133. doi: 10.1016/j.envres.2023.117133. Epub 2023 Sep 18.
Removal of methyl iodide (CHI) from the air present within nuclear facilities is a critical issue. In case of any nuclear accident, there is a great need to mitigate the radioactive organic iodide immediately as it accumulates in human bodies, causing severe consequences. Current research focuses on removing organic iodides, for which the surface of activated carbon (AC) was modified by impregnating it with different metals individually, i.e. Ag, Ni, Zn, Cu and with the novel combination of these four metals (AZNC). After the impregnation of metals, triethylenediamine (TEDA) was coated on metal impregnated activated carbon (IAC) surface. The adsorption capacity of the combination of four metals IAC was found to be 276 mg/g as the maximum for the trapping of CHI. Whereas TEDA-metal impregnation on ACs enhanced the removal efficiency of CHI up to 352 mg/g. After impregnation, adsorption capacity of AZNC and AZNCT is significantly higher as compared to AC. According to the finding, t of AZNCT IAC is 46 min, which is considerably higher than the t of other tested adsorbents. According to isotherm fitting data, Langmuir isotherm was found superior for describing CHI sorption onto AC and IACs. Kinetics study shows that pseudo second order model represented the sorption of CHI more accurately than the pseudo first order. Thermodynamic studies gave negative value of ΔG which shows that the reaction is spontaneous in nature. Based on the findings, AZNCT IAC appears to have a great potential for air purification applications in order to obtain clean environment.
从核设施内空气中去除甲基碘 (CHI) 是一个关键问题。在任何核事故的情况下,都非常需要立即减轻放射性有机碘的影响,因为它会在人体中积累,造成严重后果。目前的研究重点是去除有机碘,为此,通过单独浸渍不同金属(即 Ag、Ni、Zn、Cu)或新型的这四种金属的组合(AZNC)对活性炭(AC)的表面进行了改性。浸渍金属后,在金属浸渍活性炭(IAC)表面涂覆了三乙烯二胺(TEDA)。发现四金属 IAC 的组合的吸附容量为 276 mg/g,是捕获 CHI 的最大值。而 TEDA-金属浸渍在 AC 上提高了 CHI 的去除效率,达到 352 mg/g。浸渍后,AZNC 和 AZNCT 的吸附容量明显高于 AC。根据研究结果,AZNCT IAC 的 t 为 46 分钟,明显高于其他测试吸附剂的 t。根据等温拟合数据,发现 Langmuir 等温线更适合描述 CHI 在 AC 和 IACs 上的吸附。动力学研究表明,伪二级模型比伪一级模型更准确地表示了 CHI 的吸附。热力学研究给出了负的ΔG 值,表明反应本质上是自发的。基于这些发现,AZNCT IAC 似乎具有在空气净化应用中获得清洁环境的巨大潜力。