Degradation Of Plastic By Physicochemical Pretreatment Coupled With Biological Treatment

Due to the factors such as high yield,low recovery rate and difficult degradation of plastic,entering into the environment will not only cause damage to the ecosystem,but also pose a threat to the organisms living in it.In this paper,the physical and chemical pretreatment and biodegradation methods were coupled to screen the best plastic pretreatment methods,and Tenebrio molitor Linnaeus were used as the source of plastic biodegradation.The metabolites and intestinal flora of Tenebrio molitor Linnaeus were characterized and sequenced.To investigate the effects of physicochemical pretreatment on the degradation of plastic by Tenebrio molitor Linnaeus and the response of intestinal microorganism to feeding on pretreated plastic by Tenebrio molitor Linnaeus.This paper starts with the influence of pretreatment on plastic,and finds that the best pretreatment method of Micro PE,Micro PVC and PE Film is UV pretreatment,while the best pretreatment method of PVC Film is HNO₃ pretreatment.After pretreatment,the mass of the four kinds of plastic decreased by 6.29%,4.16%,15.34%and 13.34%,respectively,and the surface dents and cracks appeared.FTIR and Raman spectra showed that the C-C bond was broken and accompanied with the formation of C=O bond after pretreatment.In addition,the crystal structure of PE Film and PVC Film changes,Micro PVC,PE Film and plasticizer DEHP in PVC Film degrades.Tenebrio molitor Linnaeus herbivory pretreatment plastic metabolites of characterization results show that the four kinds of plastic after Tenebrio molitor Linnaeus intestinal type thermal weightlessness and structure change,C-H,C-C,C-Cl key structure is destroyed,such as plastic itself has a new C-O,C=O,C≡C,O-H,N-H functional groups such as generation,waste main ingredients for long chain alkane and long chain fatty acids.Compared with the original plastic,the thermal weight loss and crystal structure of the pretreated plastic excreta were changed.Nitric acid pretreatment promoted the degradation of PVC Film by Tenebrio molitor Linnaeus.Short-chain alkanes and long-chain fatty acids with shorter molecular chains appeared in the excreta.By analyzing the changes of microbial community structure in the intestinal tract of plastic pretreated by Tenebrio molitor Linnaeus feeding,it was found that the dominant bacteria in the intestinal tract of Tenebrio molitor Linnaeus were Hafnia,Morganella and Enterobacter,among which Enterobacter was plastic-degrading bacteria.There were no significant differences in species abundance and biodiversity of intestinal microflora between different types of plastic feeding on Tenebrio molitor Linnaeus,but the structure,functional protein and metabolic pathway composition of intestinal microflora were affected by preconditioning,while no significant differences were found in species abundance and biodiversity of intestinal microflora.In this paper,the effects of physicochemical pretreatment and biodegradation on plastic and the response of intestinal microorganism of Tenebrio molitor Linnaeus feeding pretreatment plastic were deeply explored,which is of great significance to the study of plastic pretreatment and biodegradation,and provides a new idea for improving the biodegradation efficiency of plastic.