厨余发酵液作为外增碳源强化污水处理中脱氮的规律研究

发布时间：2018-05-03 10:31

  本文选题：碳源 + 厨余发酵液　； 参考：《西安建筑科技大学》2015年硕士论文

【摘要】：实际污水处理工艺中普遍存在碳源不足而导致出水氮浓度高的问题,为了强化脱氮效率,乙酸、葡萄糖和各种工业废水等作为外增碳源的研究常见诸报端,但综合经济、效能等因素,这些碳源并没有得到广泛的应用。厨余垃圾是城市固体垃圾的重要组成部分,富含多种有机物,厌氧发酵过程中,会产生挥发性脂肪酸(VFA)、乳酸等易降解有机物,但对厨余发酵液作为反硝化碳源的研究鲜有报道。因此,本文研究了影响厨余发酵的因素以及发酵产物作为脱氮碳源的可行性。主要研究成果如下:首先,研究了初始基质浓度、温度等因素对厨余发酵产物的影响,发现总固体(TS)=13%、温度为25℃时,发酵酸化率最高,厨余发酵液SCOD=69.9g/L,其中碳水化合物、乳酸、VFAs、蛋白质分别占50%、17%、11%、6%,该混合碳源有作为反硝化碳源的潜能。利用氮去除速率(NUR)方法,对发酵液、乙酸钠、葡萄糖增强脱氮性能进行了比较,验证三种碳源的最佳碳氮比分别为6.5、4.0、10.7。在COD/N=5.0条件下,利用动力学方程对反硝化过程进行分段模拟,发现厨余发酵液组在Ss降解阶段的比反硝化速率为7.44mg NOX--N·(g VSS·h)-1,其比反硝化速率是乙酸钠的0.77倍,是葡萄糖的2.1倍,结果表明,发酵液可以作为快速降解碳源用于反硝化脱氮。通过与乙酸钠的对比,监测了发酵液作为序批式反应器(SBR)外增碳源,补充到低碳校园生活污水中强化脱氮的能力,同时利用批式实验方法,研究了两种碳源的投加量对活性污泥总氧传递速率(KLa)、氧摄取速率(OUR)的影响。结果显示,补充发酵液后会引起SBR出水氨氮的浓度小幅度增加,乙酸钠的投加对SBR出水氨氮浓度影响不大;随着发酵液和乙酸钠投加量的不断升高,饱和溶解氧(DO)、KLa都会下降,并且发酵液对混合液氧气传递能力的影响要小于乙酸钠,当投加量为300mg/LCOD当量时,反应器DO仍可维持在6mg/L,满足硝化作用对DO的要求;厨余组OUR比乙酸钠组小25.1%,氨氮氧化菌(AOB)耗氧阶段OUR比乙酸钠小52.3%,说明发酵液的投加对硝化菌活性,尤其是AOB的活性有影响。
[Abstract]:In order to enhance denitrification efficiency, the study of acetic acid, glucose and various industrial wastewater as external carbon sources are often reported, but the comprehensive economy, but the problem of high nitrogen concentration in the effluent caused by the lack of carbon source in the actual wastewater treatment process is very common, but in order to enhance the denitrification efficiency, the studies of acetic acid, glucose and various industrial wastewater are often reported. Efficiency and other factors, these carbon sources have not been widely used. Kitchen waste is an important part of municipal solid waste, which is rich in many kinds of organic matter. During anaerobic fermentation, volatile fatty acid (VFAA), lactic acid and other easily degradable organic compounds are produced. However, there are few reports on the study of kitchen waste fermentation liquid as a carbon source for denitrification. Therefore, the factors affecting the fermentation of kitchen residue and the feasibility of using fermentation products as nitrogen removal carbon source were studied. The main research results are as follows: firstly, the effects of the initial substrate concentration and temperature on the fermentation products were studied. It was found that the total solid state was 13%, and the fermentation acidification rate was the highest when the temperature was 25 鈩，

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