有机废弃物的能源回收与肥分富集技术研究

发布时间：2018-03-11 10:47

本文选题：有机废弃物处理　切入点：高温厌氧发酵　出处：《西安建筑科技大学》2015年博士论文　论文类型：学位论文

【摘要】：本研究针对以城市生活为主要来源的两类典型的有机固体废弃物——剩余污泥及粪便,根据其有机物含量、营养元素的差异分别选用厌氧共发酵技术以及好氧堆肥技术实现污泥的能源回收以及粪便的肥分富集,并对这两种技术在目前应用中分别存在的丙酸积累及有机氮损失的问题进行深入研究,提出了有效的优化策略,实现了更高效的能源回收和肥分富集。在剩余污泥的高温厌氧共发酵研究中发现,当系统负荷超过8.17g-COD/L·d时开始出现有机酸的积累,且以丙酸为主。随着负荷提升至14.6g-COD/L·d时,丙酸积累超过了2g-COD/L,系统逐渐崩溃。随后通过基质厌氧发酵动力学实验确定了基质降解的动力学特性,找出了丙酸积累的原因。并将低浓度的硫酸盐(COD:SO42-为200:1-350:1)作为电子受体加入反应体系,20天后积累的丙酸被迅速降解。成功的将高温污泥厌氧共发酵系统稳定运行的最大负荷从8.17g-COD/L·d提升至15.2g-COD/L·d,在有效的克服了高温厌氧发酵过程中丙酸积累的问题的同时,实现高负荷条件下的稳定运行,提高了能源回收效率。在以锯末为载体的粪便好氧堆肥批次实验中,通过对比温度对堆肥初始阶段及整个过程的影响,发现在中温条件下嗜温的氨化细菌会迅速的将有机氮转化为铵态氮并随着堆体p H的上升以氨气的形式溢出堆体,导致有机氮的损失高达20%。而在恒高温(55oC)堆肥过程中,不仅能够有效提高有机物的降解率,同时抑制了氨化细菌的活性,使得大量的有机氮能够被保留在堆体中,整个堆肥过程中有机氮的损失仅为5.51%。利用恒高温堆肥技术能够既实现有机物的高效降解又能有效的将有机氮保留在堆体中,大大提高堆肥产物的肥效。通过本研究可知,根据有机废弃物的成分差异,高温厌氧发酵和好氧堆肥是理想的实现能源回收和肥分富集的有机废弃物处理方法。通过反应条件的优化能够有效提高能源回收和肥分富集效率,为实际工程中有机废弃物的高效资源化提供了理论基础。
[Abstract]:In this study, two kinds of typical organic solid waste, excess sludge and feces, which are mainly derived from urban life, were studied according to their organic content. Anaerobic co-fermentation and aerobic composting were used to realize the energy recovery of sludge and the enrichment of manure, respectively. The problems of the accumulation of propionic acid and the loss of organic nitrogen in the present application of these two technologies were studied, and an effective optimization strategy was put forward. More efficient energy recovery and fertilizer enrichment were achieved. In the study of anaerobic co-fermentation of excess sludge at high temperature, it was found that the accumulation of organic acids began to occur when the system load exceeded 8.17g-COD / L 路d, and propionic acid was the main component. When the load was increased to 14.6g-COD / L 路d, The accumulation of propionic acid exceeded 2g-COD / L, and the system gradually collapsed. The reasons for the accumulation of propionic acid were found out, and the propionic acid accumulated 20 days after the addition of low concentration sulfate (COD: SO42- = 200: 1-350: 1) into the reaction system was rapidly degraded. The most successful anaerobic co-fermentation system for high temperature sludge was the most stable operation. The increase of heavy load from 8.17g-COD / L 路d to 15.2g-COD / L 路d effectively overcomes the accumulation of propionic acid during high temperature anaerobic fermentation. In the experiment of aerobic composting with sawdust as carrier, the effect of temperature on the initial stage and the whole process of composting was compared. It was found that the thermophilic ammoniated bacteria could rapidly transform organic nitrogen into ammonium nitrogen and overflow the reactor in the form of ammonia gas with the increase of pH in the reactor, resulting in the loss of organic nitrogen as high as 20%. However, in the process of composting at constant high temperature (55oC), the loss of organic nitrogen was as high as 20%. It can not only effectively increase the degradation rate of organic matter, but also inhibit the activity of ammoniated bacteria, so that a large amount of organic nitrogen can be retained in the heap. The loss of organic nitrogen in the whole composting process is only 5.51.Using the composting technology at constant high temperature, the organic nitrogen can be degraded efficiently and the organic nitrogen can be effectively retained in the compost, which greatly improves the fertilizer efficiency of the compost products. According to the composition difference of organic waste, high temperature anaerobic fermentation and aerobic composting are ideal methods to realize energy recovery and fertilizer enrichment, and the efficiency of energy recovery and fertilizer enrichment can be effectively improved by optimizing reaction conditions. It provides a theoretical basis for the efficient utilization of organic wastes in practical engineering.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：X799.3

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