Abstract:

In this study，the gas-liquid plasma was used to treat tetracycline wastewater. The oscilloscope was used to analyze the changes of current and voltage during the discharge in the gas-water condition. The luminescence spectrum was used to determine the produced reactive species by the plasma under different discharge gas components，among them，the intensity of hydroxyl radicals and active hydrogen produced by argon discharge was obviously stronger than that of other gas components. The effects of discharge power，pH，gas composition，and conductivity of solution on degradation of tetracycline were detected. The spectrophotometer was employed to measure the change of long-lived reactive species including ozone，hydrogen peroxide，etc. in the reaction system and they played important roles in the degradation of tetracycline，and the concentration of them gradually increased with the increase of the discharge time. The results showed that the removal efficiency of tetracycline could reach to 82.2% after 20 min with the condition of 19.7 W，20 mg/L tetracycline，pH 6.5 and the working gas air. Finally，the UV-visible spectroscopy of tetracycline was used to analyze the degradation mechanism，the intensity of the characteristic absorption peak of tetracycline gradually decreased with the increase of the treatment time. The reason might be that the hydroxyl and amide groups on the benzene ring and the enol on the aromatic ring were oxidized.

Key words: gas-liquid plasma, antibiotic, tetracycline wastewater

摘要：

本研究采用气液相等离子体处理四环素废水。利用示波器分析放电过程中电流和电压的变化；采用发光光谱测定等离子体在不同放电气体组分下产生的活性物质，其中氩气放电产生的羟基自由基和活性氢的强度明显比其他气体组分强；考察了放电功率、溶液pH、放电气体组分、溶液电导率对四环素去除效果的影响；利用分光光度计测定了长寿命活性物质变化情况，在放电过程中产生的长寿命活性物质包括臭氧、过氧化氢等物质对四环素的降解起到重要作用，且这些物质的浓度随着放电时间的延长逐渐增大。在放电功率为19.7 W，四环素的质量浓度为20 mg/L，pH为6.5，工作气体为空气的条件下，处理20 min时，四环素的去除效率可以达到82.2%。结合紫外-可见光谱分析存在的降解机制，四环素的特征吸收峰强度随着处理时间的延长逐渐降低，其原因可能是苯环上的羟基、酰胺基与芳香环上的烯醇被氧化。

关键词: 气液相等离子体, 抗生素, 四环素废水

CLC Number: 

• X52