Yapsakli Kozet, Aktan Cigdem Kalkan, Mertoglu Bulent
Department of Environmental Engineering, Faculty of Engineering, Marmara University, Goztepe, 34722, Istanbul, Turkey.
Department of Bioengineering, Marmara University, Goztepe, 34722, Istanbul, Turkey.
Biodegradation. 2017 Feb;28(1):69-79. doi: 10.1007/s10532-016-9778-1. Epub 2016 Nov 2.
For a successful nitrogen removal, Anammox process needs to be established in line with a stable partial nitritation pretreatment unit since wastewater influent is mostly unsuitable for direct treatment by Anammox. Partial nitritation is, however, a critical bottleneck for the nitrogen removal since it is often difficult to maintain the right proportions of NO-N and NH-N during long periods of time for Anammox process. This study investigated the potential of Anammox-zeolite biofilter to buffer inequalities in nitrite and ammonium nitrogen in the influent feed. Anammox-zeolite biofilter combines the ion-exchange property of zeolite with the biological removal by Anammox process. Continuous-flow biofilter was operated for 570 days to test the response of Anammox-zeolite system for irregular ammonium and nitrite nitrogen entries. The reactor demonstrated stable and high nitrogen removal efficiencies (approximately 95 %) even when the influent NO-N to NH-N ratios were far from the stoichiometric ratio for Anammox reaction (i.e. NO-N to NH-N ranging from 0 to infinity). This is achieved by the sorption of surplus NH-N by zeolite particles in case ammonium rich influent came in excess with respect to Anammox stoichiometry. Similarly, when ammonium-poor influent is fed to the reactor, ammonium desorption took place due to shifts in ion-exchange equilibrium and deficient amount were supplied by previously sorbed NH-N. Here, zeolite acted as a preserving reservoir of ammonium where both sorption and desorption took place when needed and this caused the Anammox-zeolite system to act as a buffer system to generate a stable effluent.
为了实现成功的氮去除，由于进水废水大多不适用于厌氧氨氧化直接处理，因此厌氧氨氧化工艺需要与稳定的部分亚硝化预处理单元协同建立。然而，部分亚硝化是氮去除的关键瓶颈，因为对于厌氧氨氧化工艺而言，长时间维持亚硝酸盐氮（NO-N）和铵态氮（NH-N）的正确比例通常很困难。本研究调查了厌氧氨氧化-沸石生物滤池缓冲进水亚硝酸盐和铵态氮不均衡的潜力。厌氧氨氧化-沸石生物滤池将沸石的离子交换特性与厌氧氨氧化工艺的生物去除作用相结合。连续流生物滤池运行了570天，以测试厌氧氨氧化-沸石系统对不规则铵态氮和亚硝酸盐氮输入的响应。即使进水的NO-N与NH-N的比例远非厌氧氨氧化反应的化学计量比（即NO-N与NH-N的范围从0到无穷大），该反应器仍表现出稳定且较高的氮去除效率（约95%）。当富含铵的进水相对于厌氧氨氧化化学计量过量时，通过沸石颗粒对过量NH-N的吸附来实现这一点。同样，当贫铵进水进入反应器时，由于离子交换平衡的变化会发生铵的解吸，先前吸附的NH-N会补充不足的量。在这里，沸石充当铵的储存库，在需要时会发生吸附和解吸，这使得厌氧氨氧化-沸石系统充当缓冲系统以产生稳定的出水。
