Preparation Of Microbial-loaded Composites And Study On Degradation Of N-hexadecane

With the rapid development of industrialization and urbanization,petroleum pollution has seriously threatened the survival and reproduction of organisms,and the damage to the ecosystem has reached an alarming degree.Therefore,the efficient elimination of petroleum pollutants in water is very important for human health and sustainable social development.significant.In recent years,the technology of loaded microorganisms has achieved certain results in the field of organic pollutant control due to its new green environmental protection advantages.This paper in order to further improve the efficiency of microbial degradation of oily wastewater,used cheap availability of biomass and waste as microbial load material,providing rich channel in order to improve the microorganism density and activity,then the surface modification with high material selection,the performance of petroleum pollutants to significantly improve the efficiency of the degradation of oily wastewater,and further illustrate the degradation mechanism（1）Rice husk carbon（RHC）was used as raw material to prepare porous carbon-based materials with good biocompatibility through crosslinking method.Oil-reducing monobacteria were selected to load on the porous structure of carbon materials,and then activated PVDF was hydrophobic on the surface,which gave it selective adsorption properties and achieved the purpose of efficient degradation of n-hexadecane.The results showed that the degradation rates of n-hexadecane by free microorganisms and microorganism-loaded porous carbon（RHC-M）were 50%and68%,respectively,while the modified microorganism-loaded porous carbon（ORHC-M）had higher degradation rates.The degradation performance of the three materials is 80.5%,and the degradation half-lives of the three materials are 4.54 d、3.89 d and 2.9 d,respectively.（2）In order to exert the synergistic effect of mixed microorganisms and simplify the preparation process,activated sludge was selected as the raw material,and the mixed oil-reducing microbial flora was doped into the prepared activated sludge（PAS）by means of multiple concentrated and loaded mixed bacterial agents.In the porous network structure,the number of microorganisms is increased and the activity of microorganisms is improved,and then the surface is hydrophobically modified with perfluorooctyltriethoxysilane（PTES）to achieve selective adsorption and efficient degradation of petroleum pollutants.The results showed that the number of viable bacteria in the activated sludge porous material（PAS-M）loaded with free mixed bacteria was 8.55×10¹²cfu/m L,which was 8000 times that of the free bacteria agent.The degradation rates of free microorganisms and PSA-M were 58.80%and 74.37%,while the modified activated sludge porous material（OPAS-M）has higher degradation performance（the degradation rate reaches 84.7%）.Finally,the degradation mechanism of n-hexadecane was studied by gas chromatography-mass spectrometry.It is finally converted into H₂O and CO₂.The selective adsorption combined with biodegradable OPAS-M opens up an efficient green route for the purification of oily wastewater.（3）In order to improve the floatability of microbial load material,achieve the purpose of repair of oily water in situ,the mixed bacteria after a load to the carbide porous asphalt material（PC）,the load of microbial oil wet porous asphalt carbon（PC-M）of poly（vinylidene fluoride）（PVDF）hydrophobic modification,make its surface form a compact hydrophobic film,the increasing of porous asphalt in the membrane structure.The mechanical strength of carbon material can effectively prevent the leakage of microorganisms and realize the purpose of efficient microbial degradation of n-hexadecane.The results showed that the degradation rates of free microorganisms and PC-M were 64.10%and 89.3%,respectively,while the hydrophobic and lipophilic loaded microbial porous carbon（OPC-M）had higher degradation performance with a degradation rate of 96.57%The degradation kinetics of PC-M and OPC-M conformed to the first-order kinetic equation,and their degradation half-lives were 3.04 d,1.23 d and 0.63 d,respectively.Therefore,the prepared OPC-M can effectively shorten the degradation cycle,and significantly prolong the floating life and service life of the microbial load material in the environment,which has more advantages and application potential in the treatment of in-situ oil spill accidents.