Biofilm formation and granule properties in anaerobic digestion at high salinity
Biofilm formation and granule properties in anaerobic digestion at high salinity
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DOI：
10.1016/j.watres.2017.05.016
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发表时间：
2017-09-15
期刊：
影响因子：
12.8
通讯作者：
Van Lier, J. B.
中科院分区：
文献类型：
--
作者：
Gagliano, M. C.;Ismail, S. B.;Van Lier, J. B.
对于含盐废水的厌氧生物处理，尽管盐浓度升高可能是一个主要障碍，但厌氧消化(AD)目前是一种可能性。厌氧菌群，尤其是产甲烷古生菌对盐度的波动非常敏感。在上流式污泥床反应器(UASB)工艺中，微生物以颗粒生物膜的形式聚集并保留在系统中，高钠浓度会对聚集产生负面影响，从而影响工艺性能。本研究分析了实验室规模厌氧处理高盐度(含钠10和20g/L)合成废水时形成的生物膜和颗粒污泥的结构。驯化后的接种物在所测试的所有盐度水平下都能达到较高的有机物去除效率。16S rRNA基因克隆分析和荧光原位杂交(FISH)分析表明，裂解甲烷藻是参与醋酸盐降解和微生物附着/颗粒化的关键因子。当外加钙(1g/L)以克服钠对微生物聚集的负面影响时，在生物膜形成过程中，微生物附着和醋酸盐降解率下降。在颗粒形成方面也观察到了同样的结果：在UASB反应器中投加钙对颗粒强度有正向影响，但不存在甲烷丝，对部分酸化基质的降解有负面影响。这项研究证明了在高盐度下获得颗粒化的可能性，使选择以丝状形式生长的甲烷菌以获得强壮和健康的颗粒的重要性凸显出来。(C)2017年作者。爱思唯尔有限公司出版。
For the anaerobic biological treatment of saline wastewater, Anaerobic Digestion (AD) is currently a possibility, even though elevated salt concentrations can be a major obstacle. Anaerobic consortia and especially methanogenic archaea are very sensitive to fluctuations in salinity. When working with Upflow Sludge Blanket Reactor (UASB) technology, in which the microorganisms are aggregated and retained in the system as a granular biofilm, high sodium concentration negatively affects aggregation and consequently process performances. In this research, we analysed the structure of the biofilm and granules formed during the anaerobic treatment of high salinity (at 10 and 20 g/L of sodium) synthetic wastewater at lab scale. The acclimated inoculum was able to accomplish high rates of organics removal at all the salinity levels tested. 16S rRNA gene clonal analysis and Fluorescence In Situ Hybridization (FISH) analyses identified the acetoclastic Methanosaeta harundinacea as the key player involved acetate degradation and microbial attachment/granulation. When additional calcium (1 g/L) was added to overcome the negative effect of sodium on microbial aggregation, during the biofilm formation process microbial attachment and acetate degradation decreased. The same result was observed on granules formation: while calcium had a positive effect on granules strength when added to UASB reactors, Methanosaeta filaments were not present and the degradation of the partially acidified substrate was negatively influenced. This research demonstrated the possibility to get granulation at high salinity, bringing to the forefront the importance of a selection towards Methanosaeta cells growing in filamentous form to obtain strong and healthy granules. (C) 2017 The Authors. Published by Elsevier Ltd.