Mechanism Study of Carbamazepine Degradation by CO<sub>2</sub>/Ar Water Film DBD Plasma

近年来，卡马西平因其高额的使用量，在自然水体中的检出率逐渐增加，寻找新的高效清洁的方法对其进行治理也成为了一项新的挑战。本研究采用同轴双介质阻挡放电反应器，以CO2和氩气为放电气体，对以水膜形式流过放电区域的卡马西平溶液进行有效降解。重点研究了不同比例CO2/Ar气氛等离子体放电对CO2转化率的影响、不同放电参数对卡马西平降解率的影响、活性物质的产生和卡马西平的降解机理。结果表明，当CO2/Ar = 1/9，总气体流量为300 mL/min时，CO2的转化率(16.84%)和卡马西平的降解率(87.58%)均达到了最高。同时随着气体中CO2/Ar比例的减小，·OH、O3和H2O2等活性物质的含量也有了一定程度的提高，这主要与放电过程中促进CO2的碰撞和解离，产生活性氧原子，并通过传质等在液相中发生一系列化学反应，形成液相活性物质相关。最后通过液相色谱–质谱联用仪对卡马西平的降解中间产物进行检测，从而分析出卡马西平可能的降解路径。本研究为等离子体降解水体中有机污染物、CO2的转化再利用提供了一种新的思路。In recent years, the detection rate of carbamazepine in natural water bodies has gradually increased due to its high usage, and it has become a new challenge to find a new efficient and clean method to treat carbamazepine. In this study, the carbamazepine solution flowing through the discharge area in the form of water film was effectively degraded by using CO2 and argon as discharge gases in a coaxial double-dielectric barrier discharge reactor. The effect of different ratio of CO2/Ar atmosphere plasma discharge on CO2 conversion, the effect of different discharge parameters on carbamazepine degradation rate, the production of active substances and the degradation mechanism of carbamazepine were studied. The results showed that when CO2/Ar = 1/9 and the total gas flow rate was 300 mL/min, the CO2 conversion rate (16.84%) and carbamazepine degradation rate (87.58%) reached the highest. At the same time, with the decrease of the CO2/Ar ratio in the gas, the content of active substances such as ·OH, O3 and H2O2 also increases to a certain extent, which is mainly related to the promotion of the collision and dissociation of CO2 during the discharge process, the generation of reactive oxygen atoms, and the formation of liquid phase active substances through a series of chemical reactions such as mass transfer. Finally, the degradation intermediates of carbamazepine were detected by liquid chromatography-mass spectrometry, and the possible degradation path of carbamazepine was analyzed. This study provides a new idea for the plasma degradation of organic pollutants in water and the conversion and reuse of CO2.