厌氧氨氧化一反硝化耦合处理合成革废水研究

采用厌氧氨氧化(Anammox)-反硝化偶合反应器处理合成革废水,在人工配水、常温、控制pH在7.5~8.0。结果表明,经过79 d的培养,历经启动初期、活性提高期、负荷提高期等3个启动阶段,系统的TN去除率达70%,成功实现厌氧氨氧化耦合反硝化的启动,系统中厌氧氨氧化和反硝化均发挥一定的TN去除作用,以厌氧氨氧化作用为主。继续运行30 d,反应器状况保持良好,在进水NO2--N与NH4+-N质量浓度的比在1.2~1.5,且COD为60~70 mg/L的条件下,TN去除率可稳定在80%以上,TN容积去除速率约0.29~0.41 kg/(m3·d)。出水水质稳定,处理效果较好。     

厌氧氨氧化反应器的接种污泥和启动策略

厌氧氨氧化细菌产率低,倍增时间长,导致厌氧氨氧化反应器启动过程缓慢,极大限制了其工程化应用,因此选择合适的厌氧氨氧化反应器的接种污泥和启动策略具有重要意义.探讨了污(废)水处理工程中常见的活性污泥用作厌氧氨氧化反应器接种污泥的基本原理、启动策略和应用效果,并对世界上第一个生产性厌氧氨氧化反应器的启动过程进行剖析,提出了加快厌氧氨氧化工程启动的"逐级富集扩大"模式.     

UASB厌氧氨氧化反应器启动研究

采用一套有效容积为3．2L的UASB反应器，接种普通城市污水处理厂污泥浓缩池污泥，以自配合NH4^＋N和NO2^-N的废水为进水，对ANAMMOX反应过程的启动和运行特征进行了研究．结果表明：进水溶解氧质量浓度为2．7～3．2mg／L，反应器的启动经历了污泥适应期、ANA-MMOX活性表现期及ANAMMOX活性提高期3个阶段，在反应器运行的第119天，NH4^＋N和NO2^-N的去除率分别为96．6％，75．4％，成功启动了厌氧氨氧化过程．在将NH^＋-N浓度从50mg／L提高到70mg／L，使进水中NH4^＋N比NO2^-N为1：1．32时，NH4^＋N、NO2^--N、TN的去除率分别达到了99．9％，99．9％和91．2％．ANAMMOX反应过程中，去除的NH4^＋-N、NO2^--N和生成的NO3^--N的比例表现为1：1．54：0．30．pH出水高于进水，稳定在8．4左右．碱度进、出水变化不大．获得的具有厌氧氨氧化活性的污泥为褐色，并在反应器的下部形成了褐色颗粒污泥．运行表明，容积负荷、反应区温度对ANAMMOX反应的稳定运行产生明显影响．     

厌氧氨氧化颗粒污泥的快速形成

以好氧硝化颗粒污泥与厌氧氨氧化生物膜作为接种污泥,在缺氧条件下利用EGSB反应器培养厌氧氨氧化颗粒污泥。根据反应器内污泥性状以及运行效果,随时调整反应器的进水基质浓度以及上升流速等关键控制因素,加快厌氧氨氧化颗粒污泥的快速形成。同时考察系统的脱氮效能、粒径分布、厌氧氨氧化颗粒污泥表面形态以及内部结构与微生物分布情况。反应器运行80 d后,培养出成熟的厌氧氨氧化颗粒污泥,平均粒径为0.556 mm;89 d时,总氮去除负荷达4.758 kg N·m^-3·d^-1。FISH表明颗粒污泥中厌氧氨氧化菌为优势菌种,同时SEM与TEM观察表明颗粒污泥是由多个小颗粒聚集形成,而且形状不规则,内部结构排列紧密。     

Three-Dimensional Stratification of Bacterial Biofilm Populations in a Moving Bed Biofilm Reactor for Nitritation-Anammox

Moving bed biofilm reactors (MBBRs) are increasingly used for nitrogen removal with nitritation-anaerobic ammonium oxidation (anammox) processes in wastewater treatment. Carriers provide protected surfaces where ammonia oxidizing bacteria (AOB) and anammox bacteria form complex biofilms. However, the knowledge about the organization of microbial communities in MBBR biofilms is sparse. We used new cryosectioning and imaging methods for fluorescence in situ hybridization (FISH) to study the structure of biofilms retrieved from carriers in a nitritation-anammox MBBR. The dimensions of the carrier compartments and the biofilm cryosections after FISH showed good correlation, indicating little disturbance of biofilm samples by the treatment. FISH showed that Nitrosomonas europaea/eutropha-related cells dominated the AOB and Candidatus Brocadia fulgida-related cells dominated the anammox guild. New carriers were initially colonized by AOB, followed by anammox bacteria proliferating in the deeper biofilm layers, probably in anaerobic microhabitats created by AOB activity. Mature biofilms showed a pronounced three-dimensional stratification where AOB dominated closer to the biofilm-water interface, whereas anammox were dominant deeper into the carrier space and towards the walls. Our results suggest that current mathematical models may be oversimplifying these three-dimensional systems and unless the multidimensionality of these systems is considered, models may result in suboptimal design of MBBR carriers.     

Treating leachate mixture with anaerobic ammonium oxidation technology

Large amounts of ammonium and a low content of biodegradable chemical oxygen demand（COD） are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment. Treatment effect of anaerobic ammonium oxidation （anammox） process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%, 74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. Thc,dcmand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the inftuent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.