| The peelable film decontamination method suppresses and fixes radioactive contamination in a short period of time.It has a high removal rate of loose radioactive pollution and produces low waste,but the harmless and minimal treatment and disposal of a large amount of residues after stripping has always been one of the key technical problems to be solved urgently.Under the condition of near normal temperature,screening and domesticating the microbial flora that can degrade the decontamination film is an important step to realize the harmless treatment of the decontamination film.In this paper,the polyacrylate-based peelable decontamination film was pre-degraded by ultraviolet light,and then the mechanical properties,thermal stability and functional group changes of the decontamination film were analyzed;The light-pretreated decontamination film was co-cultured with microbial agents to study the effect of light-pretreated film on microbial diversity and community structure,and to analyze the degradation effect of microbial flora on light-pretreated film;The degradation effect of the isolated Cupriavidus and Bacillus amyloliquefaciens on the UV predegradation film was verified,and the degradation mechanism was also analyzed.The main findings are as follows:(1)The prepared polyacrylate-based peelable decontamination film has a removal rate of more than 91%for uranium pollution on ceramic tiles,glass and stainless steel surfaces,and a removal rate of more than 71%for uranium pollution on marble surfaces.The mechanical properties of the peeling decontamination film decreased,and degradation holes and cracks appeared on the surface of the film;the UV pre-degradation film had strong absorption peaks at 1054 cm-1 and 1374 cm-1,and it was speculated that new methyl groups were introduced into the decontamination film.and hydroxyl groups;UV pre-degradation reduced the weight-average molecular weight and number-average molecular weight of the decontamination film by 55.3%and 86.80%,and the molecular weight distribution range increased by 3.38 times.The hydroperoxide generated on the surface of the decontamination film is an important substance to promote the continuous degradation of the polyacrylate decontamination film.(2)The selected bacterial inoculum can grow and reproduce in the medium supplemented with the light pre-degradable film;the microbial diversity and bacterial community structure of the bacterial inoculum are quite different from the original bacterial community,which shows that the bacterial structure is in the phylum and genus.The species and other species changed significantly,and the dominant bacteria phyla and genera were Proteobacteria and Pantoea,respectively.The results of gel chromatography showed that the light predegradation film could be degraded by bacterial agents.After culturing for 60 days,the weight-average molecular weight of the decontamination film was and number average molecular weight decreased by 9.3%and 30.73%,respectively.(3)Under the optimal culture conditions,the weight loss rate of the photopredegraded film could reach 4.86%and 5.34%in 60 days;gel chromatography analysis showed that Cupriavidus and Bacillus amyloliquefaciens Compared with the control group,the low molecular weight substances of the photopredegradation film treated with copper bacteria increased by 29%and 15%respectively,which provided sufficient carbon source for the cyclic proliferation and degradation of microorganisms,and finally realize the harmless and minimized treatment and disposal of a large number of residues after the stripping of radioactive contamination decontamination films. |
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