Degradation Of Antibiotics In Aqueous Solution By Glow Discharge Plasma

In recent years, much attention has been paid to environmental contamination and ecological poisons of antibiotics caused by antibiotics due to its widespread use and even abuse. It is not ideal to treat wastewater containing antibiotics with conventional methods. Contact glow discharge plasma (CGDP) is a kind of advanced oxidative process where plasma is sustained by direct current glow discharge around the anode between gas-liquid interface. In CGDP, active species such as hydroxyl radical and hydrogen peroxide are produced, which can oxidize the organic pollutants in the aqueous solution. CGDP has been used for the degradation of organic pollutants such as phenols, dyes and so on. However, the degradation of antibiotics with CGDP has not been reported so far.In this paper, the degradation of antibiotics in aqueous solution with CGDP was investigated, with Amoxicillin (AML) as the model pollutant. The results showed that AML underwent oxidative degradation during CGDP treatment. Under the conditions (510V,300mL, initial pH5.6and Na2SO42.0g/L), the degradation efficiency of80mg/L AML was67.27%after90min treatment; Fe2+and Fe3+showed a significant catalytic effect on AML degradation.With5mg/L Fe2+and Fe3+in presence of solution, the degradation rate of80mg/L AML reach95.29%and96.92%after30min treatment, respectively.The degradated AML with CGDP combined with photocatalysis was also investigated. It was found that the combined process was superior to the single technique. The degradation efficiency of80mg/L AML reach up to83.45%after30min treatment, with the addition of50mg of anatase TiO2into solution.In this paper, stainless steel wire was also used as anode due to its cheaper cost. It has been demonstrated that the degradation efficiency of AML increased with the increase of anode diameter and anode number. With1.0mm stainless steel wire as anode, the degradation efficiency of80mg/L AML was99.69%after90min treatment. The degradation efficiency of150mg/L AML was92.02%after30min treatment with combined process.In addition, quinolones ciprofloxacin (CIP) with CGDP was also investigated in this work. The degradation efficiency of6mg/L CIP was91.72%after90min CGDP treatment. CGDP combined with the photocatalytic technology, the degradation efficiency of6mg/L CIP was95.10%after30min treatment with the combined process and50mg anatase TiO2in presence of solution.In conclusion, CGDP can effectively degrade antibiotics in water, and the combined process of CGDP and photocatalysis can efficiently improve the degradation of antibiotics.