National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China; Beijing Drainage Group Co., Ltd., Beijing 100044, China.
Sci Total Environ. 2023 Sep 20;892:164498. doi: 10.1016/j.scitotenv.2023.164498. Epub 2023 May 29.
Anammox is a green, economical and efficient nitrogen removal process. Most successful anammox studies are based on biofilm- or granule-based systems, but pure floc sludge partial nitrification (PN) and anammox (A) systems that are not inoculated with anaerobic ammonia oxidizing bacteria (AnAOB) are rarely reported. If the anammox process occurs in floc-based systems, the large specific surface areas provide more efficient nitrogen removal, and are much more economical in terms of construction and investment. This study investigated the establishment, performance and sludge characteristics of a one-stage PN/A system with pure floc sludge and exhibited a short sludge retention time (SRT) and low mixed liquor suspended solids (SS) content. The experiment was run for approximately 1260 days and divided into five stages based on the SRTs and influent ammonia concentrations treating synthetic wastewater with no organic matter. The results showed that the AnAOB were successfully cultivated and enriched with ordinary nitrification and denitrification sludge, which formed a pure floc-based anammox system with a short SRT (at least 14 days) and a low SS control. The maximum nitrogen removal efficiency and sludge removal loading rate reached 87.1 % and 3.16 kg N/(kg VSS·d) with ammonia loading rates = 0.55 and 0.56 kg-N/(m·d), dissolved oxygen = 0.2 and 0 mg/L, temperature = 30 and 28 °C, mixed liquor volatile suspended solid (VSS) = 800 and 130 mg/L, free ammonia (FA)/VSS = 3.5 and 47.5 mg NH-N/g VSS and SRT = 30 and 15 days, respectively. Moreover, the FA/VSS ratio was used to determine the operating performance of the PN/A system, and the thresholds for inhibiting nitrite-oxidizing bacteria and ammonia-oxidizing bacteria, including AnAOB, were 0.5-50 and above 50 mg NH-N/g VSS, respectively. The floc-based one-stage PN/A systems proposed in this study provide reductions in the volumes, and floor areas for the reactor tanks, and in the cost of the carrier.
厌氧氨氧化是一种绿色、经济和高效的脱氮工艺。大多数成功的厌氧氨氧化研究都是基于生物膜或颗粒系统，但很少有报道称没有接种厌氧氨氧化菌（AnAOB）的纯絮状污泥部分硝化（PN）和厌氧氨氧化（A）系统。如果厌氧氨氧化过程发生在絮状系统中，那么大的比表面积提供了更高效的氮去除，并且在建筑和投资方面更加经济。本研究采用纯絮状污泥建立了一种单级 PN/A 系统，考察了其启动、性能和污泥特性，该系统具有短污泥停留时间（SRT）和低混合液悬浮固体（MLSS）含量。实验运行了约 1260 天，根据 SRT 和进水氨氮浓度，将其分为五个阶段，处理含有机物的合成废水。结果表明，普通硝化和反硝化污泥成功地培养和富集了厌氧氨氧化菌，形成了一种具有短 SRT（至少 14 天）和低 MLSS 控制的纯絮状厌氧氨氧化系统。在氨氮负荷分别为 0.55 和 0.56 kg-N/（m·d）、溶解氧分别为 0.2 和 0 mg/L、温度分别为 30 和 28°C、混合液挥发性悬浮固体（MLSS）分别为 800 和 130 mg/L、游离氨（FA）/MLSS 分别为 3.5 和 47.5 mg NH-N/g MLSS 和 SRT 分别为 30 和 15 天的条件下，最大脱氮效率和污泥去除负荷分别达到 87.1%和 3.16 kg-N/（kg VSS·d）。此外，采用 FA/MLSS 比来确定 PN/A 系统的运行性能，抑制亚硝酸盐氧化菌和氨氧化菌（包括厌氧氨氧化菌）的 FA/MLSS 阈值分别为 0.5-50 和 50 mg NH-N/g MLSS 以上。本研究提出的基于絮状污泥的单级 PN/A 系统减少了反应器罐的体积和占地面积，降低了载体成本。
