ABR在有机负荷影响下的基质沿程降解规律和能量回收效率

发布时间：2018-04-27 10:02

  本文选题：有机负荷 + 厌氧折流板反应器(ABR)　； 参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：废水厌氧生物处理技术因其处理负荷高并能回收沼气等优点而得到了广泛研究和应用,但也存在启动时间长、系统稳定性不理想等不足。基于生物相分离技术思想而开发的厌氧折流板反应器(Anaerobic Baffled Reactor,简称ABR),可为参与厌氧消化的各类菌群提供适宜的微环境,并通过各类群微生物构成的“食物链”实现对有机物的逐级降解和转化,大幅提高了厌氧生物处理系统的效能和运行稳定性。但关于ABR内的基质沿程降解特性与生物相分离的内在联系,认识仍不够深入,基于能量回收的控制条件优化研究也比较缺乏。本文以ABR的调控运行为基础,考察了有机负荷(Organic Loading Rate,简称OLR)对ABR处理效能和能量回收效率的影响;采用Andrews动力学模型分析了COD的沿程降解动力学特征,并进一步探讨了该特征与系统处理效能以及能量回收效率的内在联系,以期为ABR的优化控制和综合效能提高提供依据和指导。在前期运行的基础上,将ABR的运行条件控制为HRT 48 h、温度35℃、进水COD 4000 mg·L-1和p H 7.0左右等,系统可在30 d左右重新达到稳定运行状态,COD去除率和沼气产量分别达到91.8%和25.4 L·d-1左右。随着HRT从48 h分阶段缩短至16 h,系统CO D平均去除率仍能维持在90%左右,而各个格室对系统COD去除率的贡献则由以第1格室为主逐渐过渡为四个格室联合作用。通过对各个格室沼气甲烷含量及COD去除率的分析发现,采用缩短HRT提高OLR的方式,可在一定程度上强化ABR的相分离特征,提高系统的运行稳定性。系统的能量回收效率在HRT为40 h时最大,为60.5%。将HRT固定为40 h,分阶段提高COD浓度,考察OLR对ABR相分离特征与运行效能的影响。结果表明,当进水COD从2000 mg·L-1分阶段提升为8000mg·L-1时,系统均能稳定运行,其COD去除率从87.7%增加到了96.4%;发酵中间产物挥发性脂肪酸(Volatile Fatty Acid,简称VFA)主要在第1格室产生,并在后续格室中逐级得到转化和去除;丁酸和丙酸的降解分别主要发生在第2和第3格室,第4格室很少有VFA的积累;沼气产量从13.1 L·d-1大幅增加到了63.8 L·d-1,且第1和第2格室占据了总产气量的80%以上,但其甲烷含量随负荷增加而逐渐降低;系统的能量回收效率随着进水COD浓度的提高呈现逐渐下降趋势。Andrews基质降解动力学模型能够较好地模拟ABR系统中基质的沿程降解过程,由其求得的k、Ks和Ki综合表征了ABR系统内的生物相分离现象。其中,第1格室以产酸发酵菌群为主,第2和第3格室则是产氢产乙酸菌群和产甲烷菌群的功能格室,第4格室在OLR阶段性提高的调控运行过程中,功能未能全部发挥,是系统的冗余格室,可以允许系统在更高的有机负荷下运行,并对出水水质起到了保障作用。
[Abstract]:Wastewater anaerobic biological treatment technology has been widely studied and applied because of its high treatment load and the ability to recover biogas, but it also has some shortcomings such as long start-up time and poor system stability. The anaerobic baffle reactor (ABR) developed based on the biological phase separation technology can provide a suitable microenvironment for all kinds of bacteria involved in anaerobic digestion. Through the "food chain" composed of various groups of microorganisms, the organic matter can be degraded and transformed step by step, which greatly improves the efficiency and stability of the anaerobic biological treatment system. However, the internal relationship between the degradation characteristics of substrate in ABR and the separation of biological phases is not well understood, and the optimization of control conditions based on energy recovery is also lacking. Based on the regulation and operation of ABR, the effects of organic Loading rate on the treatment efficiency and energy recovery efficiency of ABR were investigated, and the kinetic characteristics of COD degradation along the route were analyzed by Andrews kinetic model. Furthermore, the relationship between the characteristics and the efficiency of system processing and energy recovery is discussed in order to provide the basis and guidance for the optimization control of ABR and the improvement of comprehensive efficiency. On the basis of previous operation, the operating conditions of ABR were controlled as HRT 48 h, temperature 35 鈩，

本文编号：1810278