餐厨垃圾和剩余污泥协同厌氧消化的试验研究

发布时间：2018-05-24 13:16

本文选题：餐厨垃圾 + 剩余污泥　；参考：《湖南大学》2015年硕士论文

【摘要】：餐厨垃圾产量日益增加,对环境造成的危害日益严峻,成为我国城市生活垃圾处理的一大难题,其营养物质丰富,可生化性高,但是在厌氧消化过程中水解速度过快导致有机酸易积累,且含盐量高、油脂高,使得反应器中的微生物活性易受到抑制。另一方面,作为我国污水处理的一大难题,剩余污泥由于可生化性较低,水解过程缓慢导致微生物的营养供应不足,进而限制了其厌氧消化的反应速率,影响了沼气的产量,所以一般常用填埋等方式处理,占用了土地且易造成二次污染。本研究旨在同时解决餐厨垃圾和剩余污泥的处理问题,又从其中获得生物能源,具有重大研究意义。本试验分别在常温和高温条件下,利用UASB反应器对餐厨垃圾和剩余污泥进行了协同厌氧消化试验研究,探索了整个连续流厌氧消化试验从颗粒污泥中微生物的复壮培养、驯化到最后的消化处理阶段出水COD浓度、COD去除率、p H值、VFA含量、沼气产量等指标的变化情况,并考察了温度对各阶段工作状态的影响,分析了不同温度协同厌氧消化的优势和劣势,以期为实际工程应用提供参考依据。试验结果表明:(1)在常温条件下进行餐厨垃圾和剩余污泥协同厌氧消化是可行的,经过较长时间的日常温度波动及昼夜温差变化的驯化,微生物可以对温度变化形成较好的适应性,常温消化最佳容积负荷为13g COD/(L·d),此时COD去除率基本可以控制在80%以上,产气量随温度波动而发生变化,处理阶段平均产气率为0.23L/g COD,甲烷含量在58%~85.1%之间波动;(2)在高温条件下对餐厨垃圾和剩余污泥进行协同厌氧消化可以大大提高容积负荷和产气率,在容积负荷为29g COD/(L·d)时达到最大产气量50.3L/d,此时COD去除率基本可以控制在85%以上,处理阶段平均产气率为0.43L/g COD,甲烷含量在56%~80.4%之间波动;(3)不同温度下的能量净产值与甲烷回收装置的能量转换效率有关,不同的城市和地区可以根据自身的条件和要求选择不同温度的协同消化。
[Abstract]:The production of kitchen waste is increasing day by day, and the harm to the environment is becoming more and more serious. It has become a big problem in the treatment of domestic garbage in our country. It has rich nutrition and high biodegradability. However, the high hydrolysis rate during anaerobic digestion resulted in the accumulation of organic acids, high salt content and high oil content, which resulted in the inhibition of microbial activity in the reactor. On the other hand, as a difficult problem in wastewater treatment in China, the low biodegradability and slow hydrolysis process of excess sludge lead to insufficient nutrient supply of microorganisms, which limits the reaction rate of anaerobic digestion and affects the production of biogas. So commonly used landfills and other methods of treatment, occupation of land and easy to cause secondary pollution. The purpose of this study is to solve the problem of treating kitchen waste and excess sludge simultaneously, and to obtain bioenergy from it, which is of great significance. In this experiment, UASB reactor was used to study the synergistic anaerobic digestion of kitchen waste and excess sludge at room temperature and high temperature respectively, and the whole continuous flow anaerobic digestion experiment was explored to regenerate microorganism from granular sludge. The change of effluent COD concentration, pH value, biogas yield and so on in the final digesting stage were investigated. The effect of temperature on the working state of each stage was also investigated. The advantages and disadvantages of synergistic anaerobic digestion at different temperatures are analyzed in order to provide reference for practical engineering application. The results show that it is feasible to combine anaerobic digestion of kitchen waste and excess sludge at room temperature. After a long time of daily temperature fluctuation and domestication of diurnal temperature difference, The optimum volumetric load of normal temperature digestion is 13g COD/(L DU, and the removal rate of COD can be controlled to more than 80%, and the gas production varies with temperature fluctuation. In the treatment stage, the average gas production rate was 0.23L/g COD, and the methane content fluctuated between 58.1% and 85.1%. Under the condition of high temperature, synergistic anaerobic digestion of kitchen waste and excess sludge could greatly improve the volumetric load and gas production rate. When the volumetric load is 29g COD/(L _ d), the maximum gas production is 50.3 L / d, and the removal rate of COD can be controlled to more than 85%. The average gas production rate in the treatment stage is 0.43L/g COD, and the energy net output value at different temperatures is related to the energy conversion efficiency of the methane recovery unit, and the methane content fluctuates between 560.40% and 80.4%. Different cities and regions can choose different temperatures according to their own conditions and requirements.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X70;S216.4

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