Degradation Of Moxifloxacin Hydrochloride And Inactivation Of Pathogenic Microbes By New Photocatalyst

Antibiotics residuals and resistant pathogenic bacteria induced by antibiotics residuals became new environmental pollutants. And Advanced Oxidation Processes including Fenton reaction and photocatalytic oxidation technology were pollution control technology for these pollutants. This paper is to study the influencing factors and kinetics properties of degradation Moxifloxacin Hydrochloride(MX) and inactivation of pathogenic bacteria by Fenton reaction and photocatalysts under visible-light irradiation.1. A new catalytic spectrophotometry method was developed for the determination of hydroxyl radical in Fenton reaction based on the Fe2+catalyzed depletion of dyes by hydrogen peroxide. The influencing factors such as pH、Fe2+concentration、reaction time and temperature were discussed. The proposed method applied to determination hydroxyl radical was simple, rapid and satisfactory, and could be used in environment field to determine hydroxyl radical and in food and pharmacy field to determine scavenging capacity of hydroxyl radical and hydrogen peroxide.2. With the degradation rate of MX and antibacterial activity as response value, the pH, Fe2+concentration, temperature were optimized by response surface methodology based on single factor experiments in Fenton reaction. The optimal reacting conditions was found to be initial pH2.3,[Fe2+]057μmol·L-1,[H2O2]0100μmol·L-1for MX30μmol·L-1at temperature44℃. Under optimal conditions,85.5%degradation efficiency in aqueous solution was achieved after30min of reaction, which was agreed with model predictions. And the residuals inhibition zone reduced to10.6mm. The pH, Fe2+、H2O2concentration, reaction medium were discussed in inactivation of K. pneumoniae, S. aureus B. pyocyaneus and E. coli by Fenton reaction. The results showed that all the pathogenic bacteria were inactivated in30min.3. A visible-light response photocatalyst AgBr@Ag3PO4(Ag2CO3) was prepared by in situ ultrasonic assisted anion-exchange method with Ag3PO4(Ag2CO3) as precursor.The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis diffuse spectroscopy. The photocatalytic activity of the prepared samples were evaluated by the degradation of MX as simulation pollutant under the visible light (λ>420nm) irradiation. The effect of several parameters such as pH value, catalyst dosage, initial moxifloxacin hydrochloride concentration and recycling runs were discussed. The photocatalysis reactive mechanisms under visible light irradiation were investigated by adding different scavengers. The results indicated that the AgBr could not change the crystal structures of Ag3PO4(Ag2CO3), and a simple physical composite material were formed in each other. The highest efficiency was obtained when the sample with the proportion0.6of Br to P(C). The AgBr@Ag3PO、AgBr@Ag2CO3photocatalyst could degrade MX up to99.8%and95.9%under illumination with500W visible lights for10min when the concentration of photocatalyst was1.5gL-1The photocatalyst could kill all of K. pneumoniae, S. aureus B. pyocyaneus and E. coli in30min with its concentration0.2gL-1.4. Graphene Oxide was prepared by Hummers method, and then GO@Ag3PO4(Ag2CO3) heterojunction was prepared by in situ ultrasonic assisted co-precipitation method. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy, UV-Vis diffuse spectroscopy, FT-IR spectroscopy and Roman spectroscopy. The photocatalytic activity and mechanisms of the prepared samples were discussed. The results indicated the efficiency enhanced with the he teroj unction structure formed between Ag3PO4(Ag2CO3) and GO because the enhanced capacity of hole and charge generation and separation.The highest efficiency was obtained when the sample with the proportion2.5of GO. The results indicated that degradation rate MX process conformed to the rule of Langmuir-Hinshelwood kinetics which followed the pseudo-first order reaction. Testing in4recycle experiments, the degradation rate of MX did not change significantly; indicating the excellent stability and reusability.The photocatalyst could kill all of K. pneumoniae, S. aureus B. pyocyaneus and E. coli in30min with its concentration0.2gL-1.