蒸汽爆破对污泥性质及厌氧消化产沼气的影响

发布时间：2018-03-25 02:06

本文选题：剩余污泥　切入点：蒸汽爆破　出处：《江南大学》2017年硕士论文

【摘要】：污水处理厂产生的城市污泥中富含大量有机质,厌氧发酵技术不仅可以将这些有机质转化为可再生能源物质,还能实现污泥的减量化和无害化,降低污泥对环境的危害。本文利用蒸汽爆破技术对城市污泥进行预处理,分析了预处理后污泥理化性质的变化,重点研究了不同预处理条件对污泥厌氧发酵的影响,探讨了预处理的条件范围;同时,还考察了汽爆污泥和餐厨垃圾联合中温厌氧发酵工艺的可行性。全文的具体研究内容和结果如下:1.通过改变蒸汽爆破预处理的压强和保压时间,比较了不同预处理条件下污泥液相中SCOD、蛋白质和多糖等有机质的溶出效果,并探究了污泥的物理结构及厌氧发酵产酸性能差异。城市污泥经蒸汽爆破预处理后,污泥液相中SCOD从空白对照的253.8 mg/L增加到9544 mg/L,比预处理前提高了37.7倍。多糖、蛋白质和核酸浓度分别较空白对照组提高12.5、19.4和3.64倍,且浓度随着预处理压强和保压时间的增加而增加。蒸汽爆破预处理改变了污泥结构和污泥粒径大小。污泥结构发生裂解,同时污泥平均体积粒径较空白对照组最高减小52.59%。汽爆预处理污泥厌氧发酵产酸结果表明,最大产酸率为234.76 mg COD/g VSS,较空白对照提高1.72倍。与其他预处理相对比,蒸汽爆破预处理具有时间短、效果好,能达到较高的产酸率等优势。2.为了探究汽爆预处理强度对污泥厌氧发酵产沼气的影响,分别设置低强度和高强度的汽爆条件对污泥进行预处理,而后用于厌氧发酵产沼气,并探讨了合适的预处理条件范围。污泥液相中SCOD、蛋白质和多糖浓度随着预处理强度的增大呈现出上升的趋势,最高分别达到9718 mg/L、866 mg/L和1457 mg/L(1.5MPa,12min)。在序批厌氧发酵产沼气过程中,汽爆污泥沼气产量显著提高。最高日产沼气达到536 m L(1.5MPa,8min),且每日沼气产量随着发酵时间而呈下降趋势。汽爆预处理污泥最大沼气产率为122.1mL/g VSadd(1.5MPa,8min),较空白对照提高5.45倍。发酵过程中pH值处在7.2-7.5的范围内,最高氨氮浓度达到1543 mg/L(1.5MPa,12min),没有对厌氧发酵过程造成抑制。在较低预处理强度下,沼气产率随着预处理强度的增加呈上升的趋势,当在较高预处理强度(1.5MPa,12min)下,沼气产率反而降低为107.6 mL/g VSadd。对于城市污泥厌氧发酵产沼气,较适合的汽爆预处理强度系数应低于4.0。3.汽爆污泥和餐厨垃圾共发酵小试研究在30 L厌氧发酵罐中进行,通过向汽爆预处理污泥中添加餐厨垃圾进行共发酵,探讨了共发酵产气效果和工艺的可行性。厌氧发酵系统启动成功后,第二、三、四阶段的平均甲烷含量和沼气产率分别为58.6%和257.1 m L/g VSadd、54.7%和339.2 mL/g VSadd、55.6%和374.6 m L/g VSadd。污泥经过汽爆预处理后混合餐厨垃圾共发酵效果要好于未预处理污泥餐厨垃圾共发酵和汽爆预处理污泥单独发酵。餐厨垃圾的加入不仅稳定了反应器运行,还使氨氮浓度从1846.4 mg/L降低至1606.8 mg/L,起到一定的稀释作用。此外,汽爆预处理污泥-餐厨垃圾共发酵TS和VS分别降低了44.6%和49.5%。这表明汽爆预处理污泥-餐厨垃圾联合中温厌氧发酵是可行的处理工艺。
[Abstract]:Rich city sewage treatment plant sludge generated in large amounts of organic matter, anaerobic fermentation technology not only can these organic matter into renewable energy material, but also to achieve reduction and harmless sludge, reducing the harm of sludge on the environment. The city sludge pretreated by steam explosion, after the change of physicochemical properties of sludge the pretreatment is analyzed, focusing on the effects of different pretreatment conditions on anaerobic fermentation of sludge, discusses the conditions of pretreatment; at the same time, also investigated the feasibility of steam explosion temperature anaerobic fermentation process sludge and food waste in the joint. The specific research contents and results are as follows: 1. by changing the pressure of steam explosion processing and packing time, compared the SCOD sludge solution with different pretreatment conditions, the dissolution effect of protein and polysaccharide, organic matter, and explores the physical structure of sludge And the fermentation performance difference. City sludge by steam explosion pretreatment, sludge liquid phase SCOD from the control of 253.8 mg/L increased to 9544 mg/L, than before the pretreatment increased by 37.7 times. The concentration of polysaccharide, protein and nucleic acid were compared with blank control group, the increase of 12.5,19.4 and 3.64 times, and with the concentration of pretreatment increase the pressure and pressure holding time increased. The steam explosion pretreatment changed the structure of the sludge and sludge particle size. The structure of the sludge cracking, and sludge volume average particle diameter than the control group the highest decrease of 52.59%. steam explosion pretreatment of sludge anaerobic fermentation results showed that the maximum rate of acid production was 234.76 mg COD/g VSS. Compared with blank control increased by 1.72 times. Compared with other pretreatment, steam explosion pretreatment has a short time, the effect is good, can achieve a higher rate of acid production of.2. in order to explore the advantages of steam explosion pretreatment on sludge strength Effect of anaerobic fermentation to produce biogas, are respectively provided with low strength and high strength of steam explosion conditions pretreatment of sludge, and then used for biogas production, and discusses the appropriate pretreatment conditions. SCOD sludge liquid phase, protein and polysaccharide concentration with increasing pretreatment intensity showing a rising trend, the highest reached 9718 mg/L, 866 mg/L and 1457 mg/L (1.5MPa, 12min). In the batch fermentation for biogas production in the anaerobic process, the steam explosion was improved. The highest daily biogas production of sludge biogas reached 536 m L (1.5MPa, 8min), and the daily biogas production with fermentation time was decreased. The steam explosion pretreatment of sludge the maximum biogas yield of 122.1mL/g VSadd (1.5MPa, 8min), compared with control increased by 5.45 times. In the fermentation process of pH value in the range of 7.2-7.5, the highest ammonia concentration reached 1543 mg/L (1.5MPa, 12min), not to make the process of anaerobic fermentation Inhibition of. At lower pretreatment intensity, the biogas yield was increased with increasing pretreatment intensity, when the intensity in the higher pre treatment (1.5MPa, 12min), but the biogas yield decreased to 107.6 mL/g VSadd. for biogas fermentation of anaerobic sludge is more suitable for the city, steam explosion pretreatment intensity coefficient should be less than experimental Study on CO fermentation in 30 L fermentor 4.0.3. steam explosion of anaerobic sludge and food waste, food waste by adding to the steam explosion pretreatment of sludge in CO fermentation, discusses the feasibility and effect of CO fermentation gas production process. The anaerobic fermentation system after a successful start, second, third, the four phase of the average methane content and the biogas yield were 58.6% and 257.1 m L/g VSadd, 54.7% mL/g and 339.2 VSadd, 55.6% m and 374.6 L/g VSadd. sludge after steam explosion pretreatment after mixed co fermentation of food waste is better than the untreated sludge Co fermentation of kitchen garbage and steam explosion pretreatment of sludge added kitchen waste fermentation. Separate not only the stability of reactor operation, the ammonia nitrogen concentration decreased from 1846.4 mg/L to 1606.8 mg/L, the dilution effect. In addition, the steam explosion pretreatment of sludge and kitchen garbage were TS and VS respectively reduced fermentation pretreatment sludge - combined temperature anaerobic fermentation of kitchen garbage in the treatment process is feasible and that steam explosion 44.6% 49.5%..

【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703;S216.4

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