Raïssa Kom Regonne, Badza Kodami, Ines Estelle Nkenmogne Kamdem, Martin Benoit Ngassoum
University of Ngaoundere, National School of Agro-Industrial Sciences (ENSAI), Department of Applied Chemistry, Laboratory of Industrial Chemistry and Bioresources (LCIB), P.O. Box 455, Ngaoundere, Cameroon.
School of Chemical Engineering and Mineral Industries, Department of Chemical Engineering, Ngaoundere, Cameroon.
Heliyon. 2024 Sep 5;10(17):e37474. doi: 10.1016/j.heliyon.2024.e37474. eCollection 2024 Sep 15.
Dechlorination of Polychlorinated Biphenyls (PCBs), carcinogenic substances used as oil in electrical transformers, remains an environmental challenge. This study aims to investigate the dechlorination of PCBs-contaminated transformer oils using microwave catalytic (Fe, glycerol) pyrolysis and to study the kinetics of PCBs dechlorination. After determining the composition of PCBs-contaminated oil using Gas Chromatography with an Electron Capture Detector (GC-ECD), response surface methodology through a central composite design was used to optimize dechlorination factors (irradiation time, microwave power, NaOH). Finally, a kinetic study of PCBs dechlorination under optimal conditions was conducted. The results showed that the concentration of PCBs in the studied transformer oil was 526 ± 0.01 mg/kg, composed of 14 congeners, with a dominance of hexa-PCBs (70 %) and penta-PCBS (18 %). The optimal PCBs dechlorination yield of 98.87 % was obtained under the following conditions: microwave power of 700 W, irradiation time of 8 min, and 0.3 g of NaOH. The kinetic study showed that PCBs degradation under optimal conditions follows a first-order reaction. These findings suggest that microwave-assisted catalytic pyrolysis is an effective and promising method for PCBs dechlorination in transformer oil, offering a potential solution for environmental remediation.
多氯联苯（PCBs）是用作电力变压器油的致癌物质，其脱氯仍然是一项环境挑战。本研究旨在研究利用微波催化（铁、甘油）热解对受多氯联苯污染的变压器油进行脱氯，并研究多氯联苯脱氯的动力学。使用带有电子捕获检测器的气相色谱法（GC-ECD）测定受多氯联苯污染的油的成分后，通过中心复合设计的响应面方法来优化脱氯因子（辐照时间、微波功率、氢氧化钠）。最后，对最佳条件下多氯联苯的脱氯进行了动力学研究。结果表明，所研究的变压器油中多氯联苯的浓度为526±0.01mg/kg，由14种同系物组成，其中六氯联苯占主导（70%），五氯联苯占18%。在以下条件下获得了98.87%的最佳多氯联苯脱氯产率：微波功率700W、辐照时间8分钟和0.3g氢氧化钠。动力学研究表明，最佳条件下多氯联苯的降解遵循一级反应。这些发现表明，微波辅助催化热解是变压器油中多氯联苯脱氯的一种有效且有前景的方法，为环境修复提供了一种潜在的解决方案。
