针-水结构纳秒脉冲气液放电降解四环素

Optimization of tetracycline degradation by nanosecond pulsedgas-liquid discharge with needle-water configuration

过度使用抗生素导致的水污染,对自然环境和人类健康造成了重大威胁。低温等离子体作为一种绿色环保的高级氧化技术,被认为是一种最具前景的抗生素降解方法之一,然而在降解效率和能量效率方面还有待进一步提高。利用纳秒脉冲放电激励针-水结构气液放电,获得了一种能产生高活性等离子体的瞬态火花模式放电,并应用于水中四环素降解,研究了脉冲电压、频率、初始浓度、初始pH值等参数对四环素降解的影响,结果表明初始浓度50 mg/L,脉冲电压9 kV、频率2 kHz,初始pH值为中性的条件下四环素的降解率最高,处理时间10 min时降解率达到了91.6%,能量效率和每阶电能分别为0.165 g·kW^(-1)·h^(-1)和0.78 kW·h·m^(-3)。自由基淬灭实验表明羟基自由基(·OH)在四环素降解过程中起主要作用,而H_(2)O_(2)和O_(3)的作用稍弱。细胞毒性实验也表明气液放电处理10 min后的溶液毒性显著下降。

Water pollution caused by the overuse of antibiotics poses a major threat to the natural environment and human health.As a green and environmentally friendly advanced oxidation technology,low-temperature plasma is considered to be one of the most promising antibiotic degradation methods,but it needs to be further improved in terms of degradation efficiency and energy efficiency.In this study,transient spark discharge was obtained by using nanosecond pulse power supply with a needle-water electrode configuration,and applied to tetracycline degradation in water.The effect of pulse voltage,frequency,initial concentration,initial pH value on tetracycline degradation was studied,and the results show that the degradation rate of tetracycline was the highest under the condition that the initial concentration was 50 mg/L,the pulse voltage was 9 kV,the frequency was 2 kHz,the initial pH is neutral,and the degradation rate reached 91.6%when the processing time was 10 min.The energy efficiency and electrical energy per order are 0.165 g·kW^(-1)·h^(-1) and 0.78 kW·h·m^(-3),respectively.Free radical quenching experiments showed that hydroxyl radicals(·OH)played a major role in the degradation of tetracycline,while H_(2)O_(2) and O_(3) played a slightly weaker role.Cytotoxicity experiments also showed that the toxicity of the solution decreased significantly after 10 min of gasliquid discharge treatment.