摘要厌氧氨氧化(Anammox)工艺是高效、经济、节能的新型生物脱氮技术。该工艺是微生物学和环境工程领域的重大发现。自问世以来就受到了高度关注。然而,厌氧氨氧化菌()倍增时间缓慢,使得如何有效保藏厌氧氨氧化污泥变得尤为必要。
本文分别考察了保藏温度和饥饿对厌氧氨氧化污泥的影响,具体如下:
(1)为考察保藏温度对厌氧氨氧化污泥颗粒特性的影响,同时优化保藏厌氧氨氧化颗粒污泥温度参数,本试验首先通过HRT调控进水基质负荷培养厌氧氨氧化颗粒污泥,并采用KHCO3和NaHCO3交替提供无机碳源。然后分别在-40°C、4°C、(27±4) °C室温和35°C条件下避光保藏。结果表明,NaHCO3可代替KHCO3作为厌氧氨氧化菌生长的无机碳源。相比于其他保藏温度,4℃保藏能够较好地维持生物量和生物活性,同时能较好地维持颗粒污泥的沉降性能、颗粒污泥和细胞结构完整性。在保藏过程中,一阶衰减指数模型可拟合厌氧氨氧化颗粒污泥生物量及活性的衰减过程,衰减指数与胞溶程度正相关,而且生物量的衰减比活性的衰减更快。同时,颗粒污泥胞外聚合物中蛋白质与多糖的比值(PN/PS)和血红素不能有效指示保藏过程中颗粒污泥沉降性能和活性的变化,而生物活性与胞溶程度呈负相关。47922
(2)饥饿对厌氧氨氧化污泥的试验在两个上流式厌氧污泥床(UASB)反应器中进行,温度设定为50°C和4°C,饥饿时间约50天。结果表明,饥饿温度对厌氧氨氧化污泥的形态和生理特性都会产生影响,且厌氧氨氧化颗粒污泥储存在4°C能够实现较低的衰减率和优良的脱氮能力,经过活化后厌氧氨氧化污泥的元素组成和PN/PS比值不变,这表明在4°C饥饿更能有效的保持污泥结构的完整性和稳定性。厌氧氨氧化颗粒在不同温度饥饿后,能在重激活的4天后恢复部分脱氮性能,在8天内得到充分激活。此外,4°C下饥饿后的恢复性能要优于20°C的。无论饥饿的温度是多少,厌氧氨氧化颗粒可以在没有基质的情况下存储长达50天,并能保持其颗粒结构和代谢潜力。
毕业论文关键词: 厌氧氨氧化;颗粒污泥;保藏温度;饥饿
Abstract
Anaerobic ammonium oxidation (Anammox) process is a novel, and energy efficient biological nitrogen removal technology. One of the major challenges in developing Anammox process is the treatment with wastewater However, anaerobic ammonia oxidation bacteria multiplication time is slow, so how to effectively preserve Anammox sludge becomes necessary.
In this paper, we studied the effect of storage temperature and starvation on Anammox sludge, the details are as follows:
(1) To investigate the effect of preservation temperature on the characteristics of anaerobic ammonium oxidation (anammox) granules and optimize the preservation temperature of anammox granules, the anammox granules were cultivated in an upflow anaerobic sludge bed (UASB) reactor through adjusting the hydraulic retention times (HRTs), and the inorganic carbon with KHCO3/NaHCO3 was alternately supplied. Subsequently, the enriched anammox granules were preserved at -40°C, 4°C, 35°C, and ambient temperature of (27±4) °C respectively. The results demonstrated that NaHCO3 can be used as the inorganic carbon for the growth of anaerobic ammonium oxidizing bacterium (AnAOB). 4°C was the best preservation temperature for maintaining anammox biomass, anammox activity, settleability, and the integrity of the anammox granule and AnAOB cell structure. During the preservation period, the first-order exponential decay model can simulate the decay of anammox biomass and activity, and the decay coefficients (bAN) of anammox biomass and activity had positive correlation with the degree of AnAOB cell lysis. Meanwhile, the rate of anammox biomass decay was larger than that of anammox activity. The ratio of protein to polysaccharide (PN/PS) in extracellular polymeric substances and heme c can not effectively indicate the changes of anammox granules settleability and activity, respectively, and the bioactivity has a negative association with the degree of AnAOB cell lysis.