暗发酵产氢菌的分离及其强化厌氧颗粒污泥活性的研究

发布时间：2018-01-15 07:01

本文关键词：暗发酵产氢菌的分离及其强化厌氧颗粒污泥活性的研究　出处：《陕西科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国造纸废水排放量占工业废水排放量16.7%,在工业废水排放放量中位居第二,其排放量大、污染物复杂、难处理等特点给造纸行业发展和人类的生存环境带来严重影响。因此,构建低成本、高效稳定的废水处理系统成为造纸企业亟待解决的问题。IC内循环厌氧反应器运行成本相对较低且稳定,目前被广泛应用于造纸行业。本文以福建某废纸造纸厂的IC内循环厌氧反应器为调研对象,采集了废水处理工艺相关数据并进行分析。在反应器运行初期CODCr去除率随进水VFA波动较大,CODCr去除率在43%~77%之间波动;在运行75 d之后,反应器对进水p H、VFA的缓冲能力增强,CODCr去除率在65%~74%变化;污泥的VSS/TSS在运行9个月后呈明显的下降趋势。同时结合XRD和FT-IR分析得出,在厌氧运行中无机盐Ca CO3逐渐沉积在污泥中,最终导致VSS/TSS逐渐下降并使厌氧颗粒污泥活性受到影响。通过对厌氧颗粒污泥的驯化,分离出高效产氢产酸菌DW01,对DW01进行16S r DNA序列分析,该菌株为Raoultella属的一个新种。并在不同的碳源、氮源、底物浓度条件下,测定了其产氢性能。在初始p H为7、15 g/L葡萄糖为碳源、0.883 g/L L-谷氨酸为氮源的条件下,DW01菌株的比产氢率为1.28 mol-H2/mol。接着进行单因素试验确定初始p H值、L-谷氨酸浓度、接种量3个因素的水平值,借助Design-Expert 8.0.5设计软件,采用Central Composite Design(CCD)设计DW01菌株发酵条件,通过响应面分析法获得最佳发酵条件为:初始p H为5.8、L-谷氨酸浓度为4.3g/L、接种量为15%。该条件下的累积氢气产量为2088.5 m L/L,比优化前提高了29.5%。最后考察DW01产氢菌对污泥龄为70 d、180 d、335 d、510 d的厌氧颗粒污泥发酵产沼气的影响。在DW01菌株的最佳生长条件下,接种等量的厌氧颗粒污泥进行序批式发酵实验。结果表明,不同污泥龄的厌氧颗粒污泥累积沼气产量不同,处于增长期的泥龄为180d的污泥产沼气活性最好,累积产沼气量为4242.7 m L/L;相同条件下分别投加DW01菌株后进行发酵实验,结果发现投加DW01菌株后污泥龄为335 d的污泥比未投加DW01菌株时累积产沼气量提高了15.2%。本文通过强化产酸菌来调控厌氧反应器内部环境,提高稳定期污泥的活性,进而为预防污泥中大量Ca CO3沉积提供了新思路。
[Abstract]:The amount of wastewater discharge in China accounted for 16.7% of industrial wastewater emissions, ranked second in industrial wastewater emissions, the emissions of pollutants, complex, difficult to deal with such characteristics bring serious influence to the development of paper industry and human living environment. Therefore, the construction of low cost, high efficiency and stability of the wastewater treatment system has become urgent in papermaking enterprises the problem of internal circulation anaerobic reactor.IC operation cost is relatively low and stable, has been widely used in papermaking industry. This paper takes Fujian papermaking factory IC internal circulation anaerobic reactor as the research object, collecting the wastewater treatment process and analyzing relevant data. The removal rate is larger with the influent VFA fluctuations in the initial stage of the reaction operation CODCr, CODCr removal rate fluctuated between 43%~77%; after 75 D operation, the reactor of influent P H, enhance the buffering capacity of VFA, the removal rate of CODCr changes in 65%~74%; sludge VS S/TSS was significantly decreased in 9 months after the operation. At the same time, according to the analysis of XRD and FT-IR that, in the anaerobic operation of inorganic salt Ca CO3 gradually deposited in the sludge, resulting in decreased gradually VSS/TSS and the activity of anaerobic granular sludge affected. The anaerobic granular sludge acclimation, separating the efficient production of hydrogen acid bacteria DW01 was analyzed by 16S r sequence of DNA DW01, a new species of the genus Raoultella. The strain and in different carbon source, nitrogen source, substrate concentration conditions, the hydrogen production performance was determined. In the initial P H 7,15 g/L glucose as carbon source, 0.883 g/ L L- for Glutamic acid the nitrogen source, DW01 strain specific hydrogen production rate was 1.28 mol-H2/mol. and the single factor experiment was conducted to determine the initial value of P H L-, glutamate concentration, inoculation amount of 3 factors level, with the help of Design-Expert 8.0.5 software, using Central Composite Design (CCD) DW01 Fermentation conditions by response surface analysis, the best fermentation conditions: initial P H 5.8, L- glutamate concentration is 4.3g/L, the inoculation is 15%. under the condition of the cumulative hydrogen yield was 2088.5 m L/L, 29.5%. DW01 improves the final inspection of hydrogen producing bacteria in the sludge age is 70 D, 180 d, 335 D than before optimization, effects of 510 D anaerobic sludge biogas production. The optimal growth conditions of DW01 strain and sequencing batch fermentation experiments of anaerobic granular sludge inoculation amount. The results showed that the anaerobic granular sludge of different sludge age cumulative biogas yield in different growth period, sludge age for biogas sludge activity 180d is the best, the cumulative biogas yield was 4242.7 m L/L; under the same conditions were added into DW01 strain for the fermentation experiment, results showed that adding DW01 strain after the sludge age is 335 D sludge than without adding DW01 strain when the cumulative biogas yield increase In this paper, 15.2%. was used to control the internal environment of anaerobic reactor and enhance the activity of sludge in stable stage by enhancing acid producing bacteria, so as to provide a new idea for preventing Ca CO3 deposition in sludge.

【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ116.2;X793

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