铜绿假单胞菌对富集镜质组新疆大南湖低阶煤的降解特性OA北大核心CSTPCD

At present,the technology of microbial degradation of low-rank coal has achieved remarkable research results.However,the composition of low-rank coal is complex,and the mechanism of microbial degradation of low-rank coal is still unclear.Therefore,accor-ding to the principle of coal petrology,the low-rank coal enriched vitrinite(vitrinite coal sample)was separated,so as to simplify the composition of coal,and then used microorganisms to de-grade the vitrinite coal sample,and then inferred the degradation characteristics of microorga-nisms on the vitrinite coal sample.A gravity separation method to extract the Xinjiang Dananhu low-rank coal enriched vitinite was employed.Subsequently,degradation experiments on the vi-trinite coal sample were conducted using Pseudomonas aeruginosa.Through both single-factor experiments and orthogonal experiments,the influences of coal slurry mass concentration,bacte-ria concentration,and degradation time on the ability of Pseudomonas aeruginosa to degrade the vitrinite coal sample were systematically investigated.The results show that the factors affecting the degradation effectiveness followed the order(from large to small)of degradation time,coal slurry mass concentration,bacteria concentration.The orthogonal experimental results indicate that the optimal conditions for Pseudomonas aeruginosa to degrade the vitrinite coal sample are the coal slurry mass concentration of 6 g/L,the bacteria concentration of 6.37×106 CFU/mL,and the degradation time of 11 d,resulting in a maximum degradation ratio of 57.1%.Proximate and ultimate analyses were subsequently conducted on the vitrinite coal sample and pretreated coal sample and remaining coal sample after degradation by Pseudomonas aeruginosa.The analy-ses reveal that following degradation,the carbon(C)and nitrogen(N)mass fraction decrease,while the hydrogen(H)and oxygen(O)mass fraction increase.Infrared analysis indicates struc-tural changes in the vitrinite coal sample,including the degradation of alkyl side chains.X-ray diffraction results show alterations,including a decrease in the spacing between aromatic layers(d002),a decrease in the stacking height of aromatic layers(Lc),a decrease in the microcrystal-line width of aromatic layers(La),and an increase in the number of aromatic layers(N).These findings indicate the ability of Pseudomonas aeruginosa to degrade the aromatic structure within the vitrinite coal sample.Furthermore,gas chromatography-mass spectrometry was employed to analyze the liquid-phase products resulting from the degradation of the vitrinite coal sample by Pseudomonas aeruginosa.The analysis reveal that in both dichloromethane and toluene extracts,alkanes are the predominant compounds,comprising over 50%of the mass fraction.Ester com-pounds are the second most abundant,exceeding 30%,with relative molecular mass concentrate in the range of 142-394.This indicates the capacity of Pseudomonas aeruginosa to degrade the vitrinite coal sample into smaller molecular compounds.Additionally,the liquid-phase products contain some amine compounds and sulfur-substituted compounds.Comprehensive ultimate anal-ysis results indicate that Pseudomonas aeruginosa can degrade nitrogen-containing structures and sulfur elements in the vitrinite coal sample.