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The degradation effects and mechanism on gemfibrozil (GEM) in aqueous solution by dielectric barrier discharge (DBD) plasma combined with the catalyst CNTs/γFe2O3 are investigated. The concentrations of plasma‐generated reactive species, including H2O2, O3, NO3−, and OH, are measured with spectrophotometric and fluorescent probes. The effects of the plasma treatment period, discharge power, initial GEM concentration, solution pH value, conductivity, and the catalytic property are studied on the degradation rate and energy efficiency. Compared with the sole plasma treatment, CNTs/γFe2O3 could maximally improve the GEM degradation rate and energy efficiency to 99.7% ± 0.2% and 76.5 ± 5.2 mg·kW−1·h−1, respectively. The solution's total organic carbon removal efficiency has been increased to 47.2% ± 2.7%. Meanwhile, the possible degradation pathways of the plasma‐treated GEM solution and overall biological toxicity of GEM degradation intermediates and residual catalyst in solution are investigated. [ABSTRACT FROM AUTHOR]

The inactivation mechanism on multidrug-resistant Acinetobacter baumannii biofilms by atmospheric-pressure helium pulse discharge plasma jet and the effect on the biofilm regeneration capacity were studied. The initial total bacterial population was 7.37 ± 0.16 log10 colony forming unit (CFU)/mL in biofilms and about 99% of the A. baumannii biofilm cells lost their cultivability after 30 min of plasma treatment. Meanwhile, resazurin fluorescent staining method showed that about 80% of the biofilm cells lost their metabolic capacity, and some bacteria entered a viable but nonculturable state. In addition, 38.3% of the bacteria lost their membrane integrity in the light of SYTO 9/propidium iodide (PI) staining assay. According to H2DCFDA fluorescent staining, the concentration of reactive oxygen species (ROS) in bacteria after plasma exposure tended to initial state after a short increase. Moreover, in the study of the regeneration ability of A. baumannii after plasma exposure for 30 min, the total bacterial number after regeneration was 5.36 ± 0.20 log10 CFU/mL. Compared with the total number of cultivable bacteria in the first-generation biofilm, about 99.99% of the bacteria were inhibited. In comparison, the biomass of the regenerated biofilm decreased to (11.0 ± 1.0)%. Meanwhile, the percentage of metabolic bacteria decreased to (52.9 ± 1.0)%. These results indicated that atmospheric-pressure helium plasma jet could not only effectively inactivate bacteria in biofilms, but also inhibit the formation of the next generation biofilms. [ABSTRACT FROM AUTHOR]

The degradation effects and mechanism on gemfibrozil (GEM) in aqueous solution by dielectric barrier discharge (DBD) plasma combined with the catalyst CNTs/γFe2O3 are investigated. The concentrations of plasma‐generated reactive species, including H2O2, O3, NO3−, and OH, are measured with spectrophotometric and fluorescent probes. The effects of the plasma treatment period, discharge power, initial GEM concentration, solution pH value, conductivity, and the catalytic property are studied on the degradation rate and energy efficiency. Compared with the sole plasma treatment, CNTs/γFe2O3 could maximally improve the GEM degradation rate and energy efficiency to 99.7% ± 0.2% and 76.5 ± 5.2 mg·kW−1·h−1, respectively. The solution's total organic carbon removal efficiency has been increased to 47.2% ± 2.7%. Meanwhile, the possible degradation pathways of the plasma‐treated GEM solution and overall biological toxicity of GEM degradation intermediates and residual catalyst in solution are investigated. [ABSTRACT FROM AUTHOR]