Heilongjiang Cold Region Wetland Ecology and Environment Research Key Laboratory, School of Geography and Tourism, Harbin University, 109 Zhongxing Road, Harbin 150086, China.
Heilongjiang Cold Region Wetland Ecology and Environment Research Key Laboratory, School of Geography and Tourism, Harbin University, 109 Zhongxing Road, Harbin 150086, China.
Bioresour Technol. 2019 Apr;278:165-174. doi: 10.1016/j.biortech.2019.01.069. Epub 2019 Jan 19.
The biofouling characteristics of an MBR (S-MBR) combined with the worm reactor and a conventional MBR (C-MBR) were analyzed, respectively, over the three-stage (fast-slow-fast) process. Whether it was in the C-MBR or the S-MBR, the species of the active sludge (AS) were similar to that of the cake sludge (CS) in stage 1 (before day 1), the bacterial adsorption and the metabolites attachment contributed to this transmembrane pressure (TMP) rise. In the stage 2, the TMP increasing rate of the C-MBR was eight times more than that of the S-MBR. During this period, a characteristic community colonized the AS and CS of the S-MBR with the microbes, ie Flavobacteria, Firmicutes and Chloroflexi which were responsible for the degradation of extracellular polymeric substances (EPS) and soluble microbial products (SMP). These dominant species caused the slower accumulation of biofouling metabolites in the CS, resulting in the slow rise-related in TMP. Meanwhile, the enrichment of β-proteobacterium and the absence of Mycobacterium and Propionibacterium in AS and CS of the C-MBR were deemed as the main biological factors bringing about the rise-associated in TMP. In the stage 3, the biofilm was matured, and the cake layer was more compacted, which resulted in an abrupt rise in TMP and severe membrane fouling. Additionally, the statistical analysis revealed that a highly correlation between the TMP increasing rate and the content of carbonhydrates in SMP (SMP). When the SMP content increased slowly, there was a relatively slow biofouling. But, when the SMP increasing rate was greater, it led to a more serious membrane fouling with the sudden TMP jump. Additionally, there was also a highly significant correlation coefficient for the TMP rise and the content of carbonhydrates in EPS (EPS) and the protein in SMP (SMP), rather than the protein in EPS (EPS). The cluster analysis showed that the microbes contributing to membrane fouling were more abundant in the C-MBR, while the microbes related to organic compounds degradation were more abundant in the S-MBR. There was significant correlation between the microbes and their metabolites. The SMP in conjunction with EPS and SMP were the main factors accelerating the membrane fouling. It was concluded that a quick rise in SMP triggered an abrupt increase in TMP, while the EPS and SMP caused the sustained increase in TMP.
分析了两段式（快-慢-快）过程中膜生物反应器（MBR）与蠕虫反应器相结合的 S-MBR 和传统 MBR（C-MBR）的生物污染特征。无论是在 C-MBR 还是 S-MBR 中，活性污泥（AS）的种类在阶段 1（第 1 天之前）都与饼层污泥（CS）相似，细菌吸附和代谢物附着导致跨膜压力（TMP）上升。在阶段 2，C-MBR 的 TMP 增长率是 S-MBR 的八倍。在此期间，微生物定殖于 S-MBR 的 AS 和 CS，形成特征群落，其中包括黄杆菌、厚壁菌门和绿弯菌门，它们负责降解胞外聚合物（EPS）和可溶性微生物产物（SMP）。这些优势物种导致 CS 中生物污染代谢物的积累缓慢，导致 TMP 相关缓慢上升。同时，C-MBR 的 AS 和 CS 中β变形菌的富集和分枝杆菌和丙酸杆菌的缺失被认为是导致 TMP 相关上升的主要生物因素。在阶段 3，生物膜成熟，饼层更加致密，导致 TMP 急剧上升和严重的膜污染。此外，统计分析表明，TMP 增长率与 SMP 中碳水化合物含量（SMP）之间存在高度相关性。当 SMP 含量缓慢增加时，生物污染相对缓慢。但是，当 SMP 增长率较大时，会导致更严重的膜污染，TMP 突然跃升。此外，TMP 上升与 EPS（EPS）中碳水化合物含量和 SMP 中的蛋白质（SMP）之间也存在高度显著的相关系数，而不是 EPS 中的蛋白质（EPS）。聚类分析表明，C-MBR 中促进膜污染的微生物更为丰富，而 S-MBR 中与有机化合物降解相关的微生物更为丰富。微生物与其代谢物之间存在显著相关性。SMP 与 EPS 和 SMP 一起是加速膜污染的主要因素。结论是，SMP 的快速上升引发 TMP 的急剧上升，而 EPS 和 SMP 导致 TMP 的持续上升。
