Operation of Submerged Anaerobic Membrane Bioreactors at 20 °C: Effect of Solids Retention Time on Flux, Mixed Liquor Characteristics and Performance
Operation of Submerged Anaerobic Membrane Bioreactors at 20 °C: Effect of Solids Retention Time on Flux, Mixed Liquor Characteristics and Performance
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DOI：
10.3390/pr9091525
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发表时间：
2021-08
期刊：
影响因子：
3.5
通讯作者：
S. Pacheco-Ruiz;S. Heaven;C. Banks
中科院分区：
文献类型：
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作者：
S. Pacheco-Ruiz;S. Heaven;C. Banks
四个平板浸没式厌氧膜生物反应器在低化学需氧量（COD）和高悬浮固体的模拟生活污水上运行了242天。有机负荷保持在1.0 g COD L-1 day-1左右，而固体停留时间（SRT）在20-90天之间变化。这是在恒定的膜通量下实现的，通过在1.8- 9.8kPa的范围内调节跨膜压（TMP）来维持。膜污染进行了评估的基础上所需的TMP，与混合液，其特征在于使用毛细管抽吸时间，冷冻图像离心和定量的胞外聚合物（EPS）。泥龄对这些参数有显着的影响：污垢是最少的泥龄为30天，最高在60天，与一些减少，因为这延长到90天。SRT < 30天的手术没有进一步的益处。虽然在短的SRT操作是最佳的膜性能，它导致较低的比甲烷生产率，更高的生物质产量和更高的出水COD。短SRT也可能加速了必需微量元素的损失，导致在这些条件下性能降低。进行了基于COD的质量平衡，包括生物质和溶解在流出物中的甲烷。
Four flat-sheet submerged anaerobic membrane bioreactors ran for 242 days on a simulated domestic wastewater with low Chemical Oxygen Demand (COD) and high suspended solids. Organic loading was maintained around 1.0 g COD L−1 day−1, while solids retention time (SRT) was varied from 20–90 days. This was achieved at a constant membrane flux, maintained by adjusting transmembrane pressure (TMP) in the range 1.8–9.8 kPa. Membrane fouling was assessed based on the required TMP, with mixed liquors characterised using capillary suction time, frozen image centrifugation and quantification of extracellular polymeric substances (EPS). SRT had a significant effect on these parameters: fouling was least at an SRT of 30 days and highest at 60 days, with some reduction as this extended to 90 days. Operation at SRT < 30 days showed no further benefits. Although operation at a short SRT was optimal for membrane performance it led to lower specific methane productivity, higher biomass yields and higher effluent COD. Short SRT may also have accelerated the loss of essential trace elements, leading to reduced performance under these conditions. A COD-based mass balance was conducted, including both biomass and methane dissolved in the effluent.