近年来，氟喹诺酮类抗生素对水体污染越来越严重对环境造成严重污染。其大分子结构复杂，在水中难以降解并产生有毒性的副产物，因此找寻高效降解氟喹诺酮类抗生素新方法有重要科学意义和应用需求。阴极微弧液相等离子体电解技术（CMPE）采用阴极放电，对有机物降解效率高，电极成本低，是一种新的有机废水处理方法，具有良好应用前景。本文利用模拟废水中加替沙星（GAT）、莫西沙星(MOX)、恩诺沙星（ENR）三种氟喹诺酮类抗生素为降解目标有机物，研究各种工艺条件下CMPE技术的降解效率，探索这些抗生素的降解机理。

实验采用钛为阴极放电，发现槽压340 V，电解质KCl，pH=7.8，浓度100 mg/L的加替沙星模拟废水条件下，8 min内加替沙星降解率达到100 %。在其它条件不变下，改变槽压为300 V，莫西沙星以及恩诺沙星模拟废水在14 min内降解效率高达95 %。结果表明，抗生素初始浓度越小，降解效果越明显，并且溶液中Cl^-的加入明显提高了降解效率。溶液酸碱性以及槽压对三种抗生素的降解效率影响有所差异，加替沙星在碱性溶液以及高电压下降解效率最高，槽压以及溶液酸碱性对莫西沙星降解效率影响不显著，恩诺沙星在酸性和低电压下降解效率稍高。

CMPE降解氟喹诺酮类抗生素过程中，在电压稳定后钛阴极周围气膜被击穿放电，放电等离子体产生紫外光、冲击波，光声空穴和高能粒子与液体相互作用产生大量自由基。自由基捕获实验发现O₂^-、h⁺、· OH为CMPE过程降解氟喹诺酮类抗生素主要自由基，将抗生素氧化断健，并且钛阴极表面形成一层薄的TiO₂膜，具有催化降解作用。

质谱分析发现，三种氟喹诺酮类抗生素结构中的哌嗪环、环丙基、羧基易被破坏，氟原子易被羟基取代。放电光谱分析表明，CMPE过程中，等子体区电子温度达到4000 – 6000 K，直接将少量抗生素碳化，但主要还是由等离子体放电激发的自由基对抗生素降解起关键作用。研究发现，光发射谱、放电噪声和样品振动频谱探测技术也是CMPE机理研究的有效辅助手段。

In recent years, fluoroquinolone antibiotics have caused more and more serious pollution to water and environment. The macromolecular structure of fluoroquinolones is complex, so it is difficult to degrade in water and produce toxic by-products. Thus, it is of great scientific significance and application demand to find a new method to degrade fluoroquinolones efficiently. Cathode microarc liquid plasma electrolysis (CMPE) is a new organic wastewater treatment method with high degradation efficiency and low electrode cost which has a good application prospect. Three fluoroquinolone antibiotics, Gatifloxacin (GAT), Moxifloxacin (MOX) and Enrofloxacin (ENR), were added into simulated wastewater as the target organic matter to study the degradation efficiency of CMPE technology in various conditions and explore the degradation mechanism of these antibiotics.

In the experiment, titanium was used as the cathode discharge. It was found that the degradation rate of gatifloxacin reached 100 % within 8 min in the condition of voltage was 340 V, electrolyte KCl, pH=7.8 and concentration was 100 mg/L. In other conditions, the degradation efficiency of moxifloxacin and enrofloxacin in simulated wastewater reached 95% within 14 min when the voltage was changed to 300 V. The results showed that the smaller the initial concentration of antibiotics, the more obvious the degradation effect, and the Cl^- in the solution significantly improved the degradation efficiency. The effects of solution acidity and voltage on the degradation efficiency of the three antibiotics were different. The degradation efficiency of gatifloxacin in alkaline solution and high voltage was the highest, the degradation efficiency of moxifloxacin in alkaline solution and high voltage was not significant, and the degradation efficiency of Enrofloxacin in acidic solution and low voltage was slightly higher.

In the process of CMPE degradation of fluoroquinolone antibiotics, the gas film around the titanium cathode is broken down and discharged after voltage stabilization, and the discharge plasma generates UV-light, shock waves, ultrasonic holes and high-energy particles interact with the liquid to produce a large number of free radicals. The free radical capture experiment showed that O₂^-, h⁺ and · OH were the main free radicals of fluoroquinolone antibiotics during CMPE process, which oxidized and broke the antibiotics, and a thin TiO₂ film was formed on the surface of the titanium cathode, which had catalytic degradation effect.

It was found by LC-MS that piperazine ring, cyclopropyl group and carboxyl group in the structure of three fluoroquinolone antibiotics were easily destroyed and fluorine atom was easily replaced by hydroxyl group. The OES analysis showed that during CMPE process, the electron temperature in the plasma region reached 4000-6000 K, which directly carbonized a small amount of antibiotics, but mainly the free radicals excited by plasma discharge played a key role in antibiotic degradation. It is found that the detection techniques of light emission spectrum, discharge noise and sample vibration spectrum are also effective auxiliary methods for the study of CMPE mechanism.