在有限丝状菌膨胀状态下 SBR 系统中饥饿条件对硝化性能和污泥特性的影响。

Impact of starvation conditions on the nitrifying performance and sludge properties in SBR system with a limited filamentous bulking state.

机构信息

College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China.

College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.

出版信息

Sci Total Environ. 2021 Nov 25;797:148997. doi: 10.1016/j.scitotenv.2021.148997. Epub 2021 Jul 13.

DOI:10.1016/j.scitotenv.2021.148997

PMID:34346374

Abstract

Limited filamentous bulking (LFB) induced by low dissolved oxygen in activated sludge system is an effective energy saving process. However, starvation environment is liable to result in the unbalance between filaments and flocs, affecting the LFB system performance. The variations in nitrifying performance and properties of LFB sludge during 14 days of four starvation conditions (aerobic, alternating anaerobic/aerobic, anaerobic and anoxic) and their subsequent recovery were investigated in sequencing batch reactor (SBR) system. The results showed that the highest activity decay rates of ammonia- and nitrite-oxidizing bacteria (AOB and NOB) were observed under aerobic starvation condition, followed by anoxic, anaerobic, and alternating anaerobic/aerobic starvation conditions. In the reactivation period, the faster recovery of AOB activity and cell number, relative to NOB, particularly in aerobic case, led to temporary nitrite accumulation. Besides, the sludge settleability rapidly improved (SVI of ~30 mL/g) due to filamentous bacteria suppression under aerobic starvation, while the filaments (e.g. Type 0092) overgrew (SVI of ~250 mL/g) under anoxic starvation, triggering unexpected biomass loss and going against the nitrifying performance recovery of the system. In contrast, alternating anaerobic/aerobic and anaerobic starvations avoid pure aerobic or anoxic starvation condition, effectively maintaining the nitrifying performance and LFB state, and therefore are the best storage strategies for LFB sludge.

摘要

活性污泥系统中低溶解氧诱导的有限丝状菌膨胀（LFB）是一种有效的节能工艺。然而，饥饿环境容易导致丝状菌和絮体之间的失衡，从而影响 LFB 系统的性能。在序批式反应器（SBR）系统中，研究了 14 天四种饥饿条件（好氧、交替缺氧/好氧、缺氧和厌氧）和随后恢复期间硝化性能和 LFB 污泥特性的变化。结果表明，在好氧饥饿条件下，氨氧化菌（AOB）和亚硝酸盐氧化菌（NOB）的活性衰减率最高，其次是缺氧、厌氧和交替缺氧/好氧饥饿条件。在再激活期间，AOB 的活性和细胞数量的恢复速度比 NOB 更快，特别是在好氧条件下，导致暂时的亚硝酸盐积累。此外，由于好氧饥饿下丝状菌的抑制，污泥沉降性能迅速改善（SVI 约为 30 mL/g），而在缺氧饥饿下丝状菌（如 0092 型）过度生长（SVI 约为 250 mL/g），引发意外的生物量损失，不利于系统硝化性能的恢复。相比之下，交替缺氧/好氧和厌氧饥饿避免了纯好氧或缺氧饥饿条件，有效地维持了硝化性能和 LFB 状态，因此是 LFB 污泥的最佳储存策略。