| Based on corn straw as raw material, this paper respectively on the biogas slurry pretreatment, combined alkali pretreatment and white-rot fungi pretreatment, the respective pretreatment time and temperature control.Determination of corn stover before and after the pretreatment of organic components content, using scanning electron microscopy, Fourier infrared spectrum and X-ray diffraction analysis of the structural characteristics of corn straw stalk fiber components, through compared with without pretreatment of corn stalk, different pretreatment of corn stalk fiber composition and characteristics of clear.Then after pretreatment of corn straw as fermentation substrates, adjusting the carbon nitrogen ratio, control of dry matter concentration is 20%, respectively, in the normal temperature, moderate solid anaerobic fermentation experiment was carried out under the condition of high temperature fermentation, the degradation rate of TS/VS, nissan, cumulative gas production rate, digestion time,the pH of the fermentation matrix and straw fibre, the content composition before and after fermentation, the fermentation substrate in consumption in the process of the monitoring of fermentation and methane bacteria and hydrogen consumption of acetic acid methane bacteria dynamic change situation, comparing the test index, discusses different fermentation temperature effects on maize straw solid anaerobic fermentation.The main conclusions obtained are as follows:(1)After pretreatment of corn straw with different ways, the content of fiber components and VS content showed a trend of decreasing. The combination of alkali treatment of straw fiber content change to the greatest extent, cellulose content reduced 8.08%, hemicellulose content decreased 10.65%, lignin content decreased by 16.79%, followed by white rot fungus pretreatment and biogas slurry pretreatment; the white rot fungus pretreatment after vs degradation rate is highest, up to 7.6%, followed by combined alkali pretreatment and biogas slurry pretreatment and vs degradation rate of 6.2% and 5.7%, respectively.(2)The scanning electron microscopy showed that the pretreatment of biogas slurry is damage to the surface of corn straw fiber, less damage, combination of alkali pretreatment on the internal structure of straw can produce great damage; Fourier transform infrared spectroscopy showed that the cellulose structure of corn straw after different pretreatments in varying degrees of damage,1365 cm-1 from C-H in the lignin bending vibration signal peaks in the combination of the alkali treatment process disappeared, indicating that the straw in combination solution under the action of the severe destruction of lignin structure; X ray diffraction results show that the amorphous region increased by pretreatment of corn straw cellulose in the crystalline structure of cellulose was part of. Destruction, crystallization degree, preprocessing is helpful to improve the hydrolysis efficiency of cellulose, is more efficient and reasonable regulation of Biogas Engineering Cheng Yu processing stage lay the foundation.(3) The degradation rate of TS and VS in pretreated corn stalk was higher than that without pretreatment. Temperature fermentation, biogas slurry pretreatment of corn stalk ts and vs degradation rate was the highest which 45.36% and 44.12%, moderate and high temperature fermentation by combined alkali pre treated corn stover ts and vs degradation rate is the highest, respectively is 52.14%,49.15% and 54.13% and 52.01%. At the same time, the cellulose degradation rate of straw pretreated by alkali pretreatment was 56.3%,58.8% and 54.36%, respectively, under the condition of different fermentation temperature. It showed that the combined alkali pretreatment significantly changed the cellulose content in the straw, and improved the hydrolysis rate of cellulose compared to the other two treatments.At the same time under the conditions of different fermentation temperature fermentation liquid pH value trend is largely the same, solid-state anaerobic fermentation is carried out by different pretreatment of corn stalk and its fermentation variation of pH value in the matrix are roughly the same.(4)Under the condition of normal temperature fermentation, the biogas slurry pretreatment of straw cumulative production volume and vs gas production were the highest, is 8157mL 158.63mL/gVS; mesophilic fermentation conditions, by combined alkali pretreatment of straw cumulative production volume and vs gas production were the highest, is 24924mL 363.64mL/gVS; under the condition of high temperature and fermentation, by combined alkali pretreatment of straw cumulative volume and vs gas production were the highest, is 23043mL 338.82mL/gVS.(5) During the fermentation period, compared with the straw without pretreatment, the amount of methane producing bacteria in the fermented substrate of pretreated straw has obvious advantages, and its metabolism and proliferation are active. Fermentation process in the consumption of hydrogen methane bacteria of the overall quantity change present startup period (0-10d) as the fermentation increases slowly at first, in the fermentation perinatal early (10) to accelerate the increase in the and fermentation production of fluorescent area reaches the maximum value, and then with the extension of fermentation time and decreased.(6) Fermentation process in the consumption of acetic acid to methane bacteria and consuming hydrogen and methane bacteria to adapt itself to the fermentation system in redox potential ability is different, in the fermentation starting period (0-10d) number was significantly increased and area of fluorescence are greater than the consumption of hydrogen methane bacteria, under the condition of high temperature, the combined alkali pretreatment of fermentation substrate consumption number of ethyl methane bacteria fermentation Od 0.96 x 104 pixels/mLby rapid rise to the 10th day of fermentation 5.36 x 104 pixels/mLand with the extension of fermentation time, showing decreasing trend, and in the fermentation Sheng perinatal stage have rebounded slightly and then decreased until the end of the fermentation. |
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