Li Jin, Zhu Weiqiang, Dong Huiyu, Wang Dan
School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Biodegradation. 2017 Aug;28(4):245-259. doi: 10.1007/s10532-017-9793-x. Epub 2017 Apr 29.
As an efficient and cost-effective nitrogen removal process, anaerobic ammonium oxidation (ANAMMOX) could be well operated at suitable pH condition. However, pH shock occurred in different kinds of wastewater and affected ANANNOX process greatly. The present research aimed at studying the performance and kinetics of ANAMMOX granular sludge with pH shock. When influent pH was below 7.5, effluent [Formula: see text]-N and [Formula: see text]-N increased with decreasing pH. At Ph 6.0, effluent [Formula: see text]-N approached 100 mg/L, and the ratios of [Formula: see text] approached 2.2 and 1.3, respectively. Both greatly deviated from theoretical values. When influent pH was above 7.5, effluent [Formula: see text]-N and [Formula: see text]-N increased with increasing pH. At pH 9.0, ammonium removal rate (ARR) and nitrite removal rate (NRR) decreased to 0.011 ± 0.004 and 0.035 ± 0.004 kg/(m·d), respectively. Besides, [Formula: see text]-N:[Formula: see text]-N deviated from theoretical value. Longer recovery time from pH 9.0 than from pH 6.0 indicated that alkaline surroundings inhibited anaerobic ammonium oxidizing bacteria (AAOB) greater. The sludge settling velocity was 2.15 cm/s at pH 7.5. However, it decreased to 2.02 cm/s when pH was 9.0. Acidic pH had little effect on sludge size, but disintegration of ANAMMOX granule was achieved with pH of 9.0. The Bell-shaped (A) model and the Ratkowsky model were more applicable to simulate the effect resulting from pH shock on ANAMMOX activity (R > 0.95), and both could describe ANAMMOX activity well with pH shock. They indicated that q was 0.37 kg [Formula: see text]-N/(kgMLSS·d) at the optimum pH value (7.47) in present study. The minimum pH during which ANAMMOX occurred was 5.68 while the maximum pH for ANAMMOX reaction was 9.26. Based on nitrogen removal performance with different pH, strongly acidic (pH ≤ 6.5) or alkaline (pH ≥ 8.5) inhibited ANAMMOX process. Besides, ANAMMOX appeared to be more susceptible to alkaline wastewater. Compared to extremely acidic condition (low pH), extremely alkaline condition (high pH) affected ANAMMOX granules much more.
作为一种高效且经济的脱氮工艺，厌氧氨氧化（ANAMMOX）在适宜的pH条件下能够良好运行。然而，不同类型的废水会出现pH冲击，对厌氧氨氧化工艺产生极大影响。本研究旨在探讨pH冲击对厌氧氨氧化颗粒污泥性能和动力学的影响。当进水pH低于7.5时，出水[公式：见原文]-N和[公式：见原文]-N随pH降低而增加。在pH为6.0时，出水[公式：见原文]-N接近100mg/L，[公式：见原文]的比例分别接近2.2和1.3，均与理论值有较大偏差。当进水pH高于7.5时，出水[公式：见原文]-N和[公式：见原文]-N随pH升高而增加。在pH为9.0时，氨氮去除率（ARR）和亚硝酸盐去除率（NRR）分别降至0.011±0.004和0.035±0.004kg/(m·d)。此外，[公式：见原文]-N:[公式：见原文]-N偏离理论值。从pH为9.0恢复所需的时间比从pH为6.0恢复所需的时间更长，这表明碱性环境对厌氧氨氧化细菌（AAOB）的抑制作用更大。在pH为7.5时，污泥沉降速度为2.15cm/s。然而，当pH为9.0时，沉降速度降至2.02cm/s。酸性pH对污泥粒径影响较小，但在pH为9.0时会导致厌氧氨氧化颗粒解体。钟形（A）模型和拉特科夫斯基模型更适用于模拟pH冲击对厌氧氨氧化活性的影响（R>0.95），两者都能很好地描述pH冲击下的厌氧氨氧化活性。研究表明，在本研究的最佳pH值（7.47）下，q为0.37kg[公式：见原文]-N/(kgMLSS·d)。厌氧氨氧化发生的最低pH为5.68，而厌氧氨氧化反应的最高pH为9.26。基于不同pH下的脱氮性能，强酸性（pH≤6.5）或碱性（pH≥8.5）条件会抑制厌氧氨氧化工艺。此外，厌氧氨氧化似乎对碱性废水更敏感。与极端酸性条件（低pH）相比，极端碱性条件（高pH）对厌氧氨氧化颗粒的影响更大。
