玉米秸秆厌氧消纳沼液工艺参数优化

发布时间：2018-03-26 22:32

本文选题：秸秆　切入点：沼液　出处：《沈阳农业大学》2017年硕士论文

【摘要】：近几年来,我国大中型沼气工程在国家政府的大力鼓舞下发展迅猛,沼液的合理处理已成为治理环境污染的重中之重。本文以秸秆厌氧消纳沼液为基础进行以下几个方面的研究。对沈阳市某沼气工程进行取样,分别从营养状况、有毒有害污染物和卫生情况三方面对沼渣沼液特性对比分析。结果表明:(1)该沼气工程沼液中的各项营养成分基本上低于有机肥中各项含量。沼渣中的总养分略低于有机肥中该项的标准值,速效总养分已达标准值,有机质含量远远超过标准值。(2)该沼气工程沼渣中的总养分、有机质含量远远高于沼液;速效总养分略高于沼液,因此沼渣可以直接作为肥料。而沼液由于营养低、产量大,如何处理沼液已成为重中之重。(3)该沼气工程的沼渣沼液卫生指标绝大多数符合标准规定,基本不会对农作物和土壤造成危害。(4)该沼气工程沼渣沼液中的汞、砷、镉、铅和铬含量均低于标准值。研究了温度、光照条件、氧气含量和贮存时间对沼液成分的影响,分析影响因素的主次。试验结果表明:(1)沼液中的总氮、速效氮和氨氮含量逐渐减少,当沼液在30°C,遮光厌氧条件下贮存60天时达最低值,分别为285.2 mg/L、273.5mg/L、202.8 mg/L。(2)沼液的总磷和速效磷含量逐渐下降,当温度为30°C,在遮光好氧条件下贮存30天时的速效磷含量最低,为3.5mg/L。(3)沼液中的总钾、速效钾含量呈现下降的趋势。(4)综合沼液中各成分,温度和氧气含量是主要影响因素,而贮存时间和光照条件则是次要影响因素。以秸秆和沼液为发酵原料,研究不同TS对其发酵的影响,根据产气效果确定秸秆厌氧消纳沼液的最适TS为10%、15%和20%。以秸秆和沼液为发酵原料,根据Box-Behnken试验设计原理,建立了累积产气量与TS、堆沤比和原料配比之间的数学模型,通过调节TS、堆沤比和原料配比,以产气效果为指标确定秸秆厌氧消纳沼液的初步发酵工艺条件,在此基础上,以1000 m3沼气工程进行应用分析,通过秸秆连续厌氧消纳沼液工艺,消纳1000 m3沼气工程日沼液排放量,确定秸秆厌氧消纳沼液的最佳工艺参数条件。结果表明:(1)回归方程的相关系数R2为0.9684,在0.01水平上显著,表明回归方程和试验结果的拟合度较好。(2)影响秸秆厌氧消纳沼液的因素主次为堆沤比TS原料配比。(3)以产气效果为指标,秸秆厌氧消纳沼液的初步发酵工艺参数是:TS为19%,原料配比(秸秆:沼液)为0.88,堆沤比(沼液:秸秆)为3.5。(4)对于1000 m3沼气工程的日产沼液量,可用一个容积为225m3,TS为18.1%的秸秆连续厌氧消纳沼液工程进行处理。(5)确定秸秆厌氧消纳沼液的最佳发酵工艺条件为TS为18.1%,原料配比(秸秆:沼液)为0.88,堆沤比(沼液:秸秆)为 3.50。
[Abstract]:In recent years, large and medium-sized biogas projects in China have developed rapidly under the strong encouragement of the national government. The rational treatment of biogas liquid has become the most important part of environmental pollution control. Based on the straw anaerobic digesting biogas liquid, the following aspects are studied in this paper. A biogas project in Shenyang is sampled, and the nutritional status of the biogas project is analyzed. The characteristics of biogas sludge from three aspects of toxic and harmful pollutants and sanitary conditions were compared. The results showed that the nutrients in the biogas engineering biogas slurry were basically lower than those in organic manure, and the total nutrients in the biogas residue were slightly lower. The standard value of the item in organic fertilizer, The total available nutrients have reached the standard value, and the organic matter content is far higher than the standard value. 2) the total nutrients in the biogas engineering biogas residue are much higher than those in the biogas sludge, and the available total nutrients are slightly higher than the biogas liquid. Therefore, the biogas residue can be used as fertilizer directly. However, because of the low nutrition and high yield of the biogas liquid, how to deal with the biogas liquid has become the most important one.) most of the sanitary indexes of the biogas sludge of the biogas project accord with the standard regulations. The contents of mercury, arsenic, cadmium, lead and chromium in the biogas engineering sludge are all below the standard value. The effects of temperature, illumination, oxygen content and storage time on the composition of the biogas liquid were studied. The results showed that the contents of total nitrogen, available nitrogen and ammonia nitrogen in the biogas fluid decreased gradually, and the lowest value was reached when the biogas liquid was stored at 30 掳C for 60 days under shading anaerobic condition. The total phosphorus and available phosphorus content of the biogas liquid decreased gradually. When the temperature was 30 掳C, the available phosphorus content was the lowest when stored under shading and aerobic conditions for 30 days, and the total potassium in the biogas liquid was 3.5 mg / L 路L ~ (2 +) 路L ~ (2 +) 路L ~ (2) ~ (2) mg 路L ~ (2) mg 路L ~ (2) 路L ~ (-1) 路L ~ (2) 路L ~ (-1) 路L ~ (2). The content of available potassium decreased. 4) temperature and oxygen content were the main influencing factors, while storage time and light condition were the secondary factors. Straw and biogas liquid were used as raw materials. The effects of different TS on fermentation were studied. According to the effect of gas production, the optimum TS of straw anaerobic digesting biogas was determined to be 1015% and 20% respectively. The straw and biogas liquid were used as raw materials for fermentation, and according to the principle of Box-Behnken test design, The mathematical model between cumulative gas production and TSS-retting ratio and raw material ratio was established. The preliminary fermentation conditions of straw anaerobic digesting biogas liquid were determined by adjusting TSS, retting ratio and raw material ratio, taking the gas production effect as the index, on the basis of which the fermentation conditions of straw anaerobic digesting biogas liquid were determined. The application analysis of 1000 m3 biogas project was carried out. Through the continuous anaerobic digestion of straw, the daily amount of biogas liquid of 1000 m3 biogas project was absorbed. The results showed that the correlation coefficient R2 of the regression equation was 0.984, which was significant at 0.01 level. The results showed that the regression equation and the test results fit well. 2) the main and secondary factors affecting straw anaerobic digesting biogas liquid were compost TS raw material ratio. 3) the effect of gas production was taken as the index. The initial fermentation parameters of straw anaerobic digesting biogas liquid were: 1: TS = 19, raw material ratio (straw: biogas liquid) = 0.88, compost ratio (biogas liquid: straw) = 3.5.4for daily biogas production of 1000 m ~ 3 biogas engineering, The optimum fermentation conditions of straw anaerobic digesting biogas liquid were determined as TS = 18.1, raw material ratio (straw: biogas liquid) 0.88 and compost ratio (biogas liquid: straw) 3.50. The optimum fermentation conditions of straw anaerobic digesting biogas liquid were determined as follows: TS = 18.1, the ratio of straw to biogas was 0.88, and the ratio of compost to compost (biogas: straw) was 3.50.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S216.4

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