| In this study, Eucommia ulmoides Oliv. branch was pyrolyzed to prepare the crudepyroligneous acid at different pyrolysis temperature (550℃,650℃,750℃,850℃,950℃)by using high temperature rotary kiln, which were recorded as DC550, DC650, DC750,DC850, DC950, distilling the five groups of crude pyroligneous acid in rotary evaporationinstrument at80℃, after standing, refining them by the preliminary siphon, then determiningits physical and chemical indicators, antioxidant activity and antibacterial activity. Amongthese measurement results, selecting DC550as material for subsequent experiments.Usingultra-low temperature freezing and thawing method, activated carbon adsorption method todeal with DC550, DL550and DX550were prepared. Then studying and comparing theantibacterial activity and antioxidant activity of three groups of pyroligneous acid; andselecting better-DC550to soak the Brassica campestris L. seeds,in order to study the effecton seed germination and seedling growth after dealing with different concentration of it andanalyzed its compounds by GC-MS. Test results were as follows:.1.The wood flour of Eucommia ulmoides Oliv. Contains a low moisture content (6.03%);the contents of cellulose, hemicellulose, lignin were35.52%,22.48%,15.08%, respectively;carbon content of Eucommia ulmoides Oliv. flour was45.05%and sulfur content was only0.04%, so Eucommia ulmoides Oliv. branch can be used as an excellent timber to producecharcoal.2.The crude pyroligneous acid (DC550) was collected at550°C had the minimum pH(2.40), while at850°C, it (DC850) had the highest pH (3.41) accordingly. The content oforganic acid and refractive index were the highest in DC550, and in DC650, they were thelowest. The content of dissolved tar and combustion residue in these pyroligneous acids werevery poor. With the increase of the dilution ratio, pH of these pyroligneous acid increased.Analysing composition and content of these pyroligneous acid, the results showed thatcontent of amino acid in DC850was the highest, and in DC550was the lowest. As the timechanged, color of DC550and DC850were more obvious. In this study, the physical andchemical properties of the five kinds of pyroligneous acid were researched, which canprovided a experimental basis for processing different production purposes in the practice, inorder to select different termination temperature pyroligneous acid based on different application.3.The physical-chemical indicators and phenol content had significant differences in fivegroups of pyroligneous acids, and the total phenol content in DC550was the maximum(666.80mg/g); the scavenging activities of pyroligneous acid on DPPH· and ABTS· freeradicals were inferior to Vc among the five groups of pyroligneous acid, and the order was Vc＞DC550＞DC750＞DC850＞DC650＞DC950;5groups of pyroligneous acids hadantimicrobial activities and the differences were significant, DC550exhibited the strongestantimicrobial activities among5groups of pyroligneous acids and the range of EC50to plantpathogens was0.77～1.52mg/g. High antioxidant activities and antimicrobial activities ofDC550might be related to its high contents of total phenol and organic acids.4.The three groups of wood vinegar had antibacterial activity and antioxidantactivity,and the bacteriostatic activity of them were in an order of DC550> DL550> DX550,while the significance of difference to different strains of three groups of wood vinegar weredifferent; the range of EC50to plant pathogens was0.77～1.52mg/g in DC550. thescavenging activities of pyroligneous acid on DPPH· and ABTS· free radicals were inferior toVc,and the order was Vc> DC550> DL550> DX550,the order of total phenol content in3groups of pyroligneous acid was in line with the order of antioxidant activity.5.The results showed that dilution multiples of200,800of pyroligneous acid hadsignificant inhibitory effect on seed germination rate, germination potential, chlorophyllcontent and biomass of seedlings and buds length, which proved it has the potential foragricultural growth promoters; with the increase of dilution ratio, the effect of any indicatorsabove had a certain promoting effect, and compared with CK, the effect on the germinationrate, germination potential was not significant.6.DC550contained33kinds of compounds, accounting for96.79%of the total peaksurface. Among them, phenolic was the most (74.48%), and contained16kinds of compounds;ketones followed it, accounting for10.76%, and contained7kinds of compounds, amongthem, the main ingredient was3-methyl-2-hydroxy-2-Cyclopentenone; the content of organicacid (10.63%) was similar to ketones, and the main component was acetic acid (7.12%); alsoa small amount of alcohol and other components were detected, and the content was0.28%and0.34%, respectively. |
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