【作者】 高小平；

【导师】 吉方英；

【作者基本信息】 重庆大学 ， 环境工程， 2005， 硕士

【摘要】 根据生物除磷代谢机理模式可知,厌氧/好氧或厌氧/缺氧环境的交替变化都可以诱导磷的超量吸收,前者以分子氧作为电子受体、后者以NO₃^--N作为电子受体。由于NO₃^--N电子受体传递链短、氧化还原电位低,产生ATP只有氧电子受体的2/3。因此,从生物除磷的角度分析,缺氧吸磷不如好氧吸磷。但由于缺氧吸磷过程将反硝化和磷吸收融为一体,从能耗角度认为缺氧吸磷是一种节约能源的新陈代谢模式,且已有大量资料表明,在达到相同的营养盐去除效果时,缺氧吸磷与好氧吸磷相比可以减少75%的氧耗量,同时能削减50%以上富磷污泥排放量。但迄今为止,对反硝化除磷系统污泥的活性以及反硝化除磷系统的稳定运行性能具有两种截然不同的试验结果:1)厌氧/缺氧（A/A）试验装置在不需要好氧的情况下能长期、稳定运行;2)伴随着运行过程的进行,单纯的A/A系统生物量将逐渐减少,除磷能力逐渐消失。为此,本文拟定对影响反硝化除磷系统除磷能力和稳定运行性能的主要因素做进一步探讨,通过反硝化除磷系统单因素影响试验（主要从NO₃^--N浓度,厌氧、缺氧、后好氧时间,污泥龄,碳源基质COD浓度几个方面进行考察）和反硝化除磷系统的优化试验（四因素四水平正交试验）的研究,研究结果表明: ①增加后好氧段是保证反硝化除磷系统稳定运行的关键,在本试验条件下0.5h的后好氧时间即可保证A/AO-SBR系统的稳定运行又可以获得良好的反硝化除磷效果。 ②在厌氧/缺氧反硝化除磷系统和厌氧/缺氧/后好氧反硝化除磷系统的运行过程中,启动初期均可观察到较为明显的反硝化除磷现象,但在厌氧/缺氧过程中,随着运行时间的延长,其除磷效果逐渐变差,污泥产率也将下降甚至呈负增长状态,最终生物除磷能力丧失。在厌氧—缺氧—好氧过程中,创造适宜条件,系统的缺氧段有良好的聚磷效果,并且该系统在此条件下能长期稳定的运行。 ③当厌氧时间为2h,缺氧时间为3.5h时,缺氧段初期投加NO₃^--N浓度为30mg/L时,能够获得良好的除磷效果。并且缺氧段末期脱氮率达到98%。 ④污泥龄是影响A/AO-SBR反硝化除磷系统正常运行的又一重要因素,本研究通过对比试验得出,在A/AO-SBR系统中,当按照厌氧时间为2h,缺氧时间为3.5h,好氧时间为0.5h,沉淀时间为2h的运行工况运行时,污泥龄为25d时,能获得较好的除磷效果。 ⑤通过正交试验得出当保证在进水COD浓度为250mg/L,PO₄^3--P浓度为4.3～5.8mg/L,NH₃-N浓度为20～25mg/L时A/AO-SBR系统能长期稳定运行,并更多还原

【Abstract】 According to mechanism of biological phosphorus removal, phosphorus is assimilated superfluously in A/O or A/A. In A/O, Phosphorus bacteria takes the oxygenous molecule for the electronic accepter, in A/A, （NO₃）^--N is took for the electronic accepter. Owing to short transfer link and low redox of （NO₃）^--N, ATP that （NO₃）^--N produces is two third times for that oxygenous molecule does. From the angle of biological phosporus removal, absorbency of phosphorus in anoxic condition is lower than in aerobic condition. However, Nitrogen removal and phosporus removal are syncretized in the anoxic process of phosporus removal, and from the angle of that energy which is consumed, phosporus removal in anoxic condition is a metabolic mode that can retrench energy sources. Large numbers of date indicated that it can reduce 75 percent of oxygenous wastage in anoxic condition compared with in aerobic condition ,and it can cut over 50 percent of discharged rich phosphorus sludge. So far, There are two different test result about activity of sludge and steady function in the system of denitrifying phosphorus removal, as follows: l)It can run stably and chronically in A/A. 2)Along with run time increasing , biomass will decrease gradually in the system of A/A . Therefor, in this dissertation, author will study the main influencing factors that influence the ability of phosphorus removal and long and steady run in the system of denitrifying phosphorus removal.In the material course of study, author went along a few phases of research through single factor test in the system of denitrifying phosphorus removal （It is studied mainly basing on some factors about concentration of （NO₃）^--N, anaerobic time, anoxic time, aerobic time, SRT and COD, etc.） and orthogonal test in the system of denitrifying phosphorus removal （according to four factors and four levels of the Orthogonal test）.According to the above study results, it indicated that: ①The key to make the system of denitrifying phosphorus removal oprerate steadily is increasing the latter aerobic time. It was also found in the test that the latter aeration for 0.5h would ensure not only steady operation, but also good effect of phosphorus removal in the system of A/AO-SBR.② In the system of A/A-SBR or the system of A/AO-SBR, they all could be found the phenomena of denitrifying phosphorus removal in the earlier stage of test, However, along with the run time increasing in the system of A/A-SBR, the effect of phosphorusremoval would weaken, Ys will also decrease gradually to zero or even minus, the ability of phosphorus removal camedown finally. In the system of A/AO-SBR, the anoxic course would gain favorable effect when it was controlled in feasible condition, and it could run chronically and stably.（3） When anaerobic time is 2h, anoxic time is 3.5h, concentration of NO_<sup>--N is 30mg/L in the initial stage of anoxic course, the system of A/A could gain favorable effect of phosphorus removal.④ SRT is also a pivotal factor that affected the long and steady run of the system of A/AO-SBR. It was found through the test , when the system run according to anaerobic time for 2h,anoxic time for 3.5h, aerobic time for 0.5h, concentration of NO_<sup>-N is 30mg/L, SRT was 25d, it could gain better effect of phosphorus removal.（5） Through Orthogonal test, it indicated that the optimal condtion of the long and steady run for the system of denitrifying phosphorus removal is anaerobic time for 2h,anoxic time for 3.5h, aerobic time for 0.5h, concentration of NO_<sup>--N is 30mg/L, SRT was 25d, when concentration of COD was250mg/L, concentration of （PO₄）^3--P was 4.3-5.8mg/L, concentration of NH3-N was 20-25mg/L in inflow.（6） Through the ability of the system of traditional biological phosphorus removal comparing with the ability of the system of denitrifying phosphorus removal, it was found that the system of denitrifying phosphorus removal have the ability of phosphorus removal ,but it was lower than the system of traditional biological phosphorus removal. General factors that affected the ability of phosphorus removal were SRI、 sludge productivity 、 content of phosphorus in surplus sludge, etc.（7） Through searching the kinetic mode of the system of denitrifying phosphorus removal, the followings were deduced: a) the kinetic mode of （PO₄）^3--P that was released in anaerobic course was P_t=P₀—3.15XTt² +10.1Xt, b) the kinetic mode of （PO₄）^3--P that was absorbed in anoxic course was P_t’=Po+7.6X+2.2t²— 14t.This dissertation belongs to the task that was staked by China Natural Science Fund and Cadreman of Chongqing University. The researchs can offer some academic evidence for study about technics denitrifying phosphorus removal. So ,the researchs are important both in application and theory.更多还原