Boroojerdi Saeed Hassan, Mohammadi Mohsen Mir, Bahadoran Farzad
Department of Environmental Engineering, Faculty of Environment, University of Tehran Tehran Iran
Department of Gas Processing and Transmission Development, Research Institute of Petroleum Industry Tehran Iran
RSC Adv. 2025 Jul 31;15(33):27311-27333. doi: 10.1039/d5ra01361e. eCollection 2025 Jul 25.
Solid adsorption effectively removes hazardous air pollutants like dichloromethane (DCM), thereby mitigating serious environmental problems. In this study, activated carbon (AC) was innovatively prepared from peanut shells using a single-step physical-chemical activation technique involving CO and potassium oxalate monohydrate (POM). The synthesis focused on properties, cost, and environmental impact. Optimization of AC preparation conditions employed central composite circumscribed design (CCCD) to maximize specific surface area ( ) and production yield ( ). Two quadratic models described the relationship between synthesis variables: activation temperature ( , °C), impregnation ratio (IR, g g), and CO gas flow rate (L h) for each response. The optimized activated carbon (POMCO-AC) exhibited an of 1100 m g and a of 21%, matching predicted values. Characterization tests indicated minimized macropores, high porosity with 83% micropore distribution, and appropriate surface chemistry. Column adsorption tests demonstrated that POMCO-AC efficiently eliminates DCM from a contaminated gas stream. Langmuir, Freundlich, and Langmuir-Freundlich models were employed for adsorption isotherm analysis. The evaluation of adsorption kinetics data was conducted using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The results indicated that the Langmuir isotherm and pseudo-first-order models described the experimental data more accurately than other models. The maximum adsorption capacity ( ) was determined to be 298 mg g at 273 K. The adsorption mechanism was found to be governed by intraparticle diffusion in combination with the film diffusion. The study reveals that the applied preparation method effectively converts agricultural wastes, such as peanut shells, into an efficient and low-cost adsorbent for removing pollutants, making it suitable for industrial-scale air purification.
固体吸附能有效去除二氯甲烷（DCM）等有害空气污染物，从而缓解严重的环境问题。在本研究中，采用涉及一氧化碳（CO）和一水合草酸钾（POM）的单步物理化学活化技术，创新性地从花生壳制备了活性炭（AC）。合成过程着重考虑了性能、成本和环境影响。采用中心复合外切设计（CCCD）对AC制备条件进行优化，以最大化比表面积（ ）和产率（ ）。两个二次模型描述了合成变量（活化温度（ ，°C）、浸渍比（IR，g/g）和CO气体流速（L/h））与各响应之间的关系。优化后的活性炭（POMCO-AC）比表面积为1100 m²/g，产率为21%，与预测值相符。表征测试表明，其大孔最少，孔隙率高，微孔分布占83%，且表面化学性质适宜。柱吸附测试表明，POMCO-AC能有效从污染气流中去除DCM。采用朗缪尔、弗伦德里希和朗缪尔-弗伦德里希模型进行吸附等温线分析。使用准一级、准二级和颗粒内扩散模型对吸附动力学数据进行评估。结果表明，朗缪尔等温线和准一级模型比其他模型更准确地描述了实验数据。在273 K下，最大吸附容量（ ）确定为298 mg/g。发现吸附机制受颗粒内扩散与膜扩散共同控制。该研究表明，所应用的制备方法能有效地将花生壳等农业废弃物转化为一种高效、低成本的污染物去除吸附剂，适用于工业规模的空气净化。
