School of Environment, Tsinghua University, Beijing100084, China.
School of Environment, Tsinghua University, Beijing100084, China; Research Institute for Environmental Innovation (Suzhou) Tsinghua, Suzhou215163, China.
Water Res. 2021 Jun 15;198:117152. doi: 10.1016/j.watres.2021.117152. Epub 2021 Apr 13.
Biologically activated carbon (BAC) filters are widely used in China and worldwide as an essential part of advanced water treatment. However, it is unclear how to properly select the granular activated carbon (GAC) used in BAC filters and to determine when GAC should be replaced. In this study, five BAC filters, each filled with a different coconut- or coal-based GAC with different physicochemical properties, were run continuously for 400 days. The structure and function of the microbial community and the quantity of specific enzymes in the BAC filters were investigated through an integrated metagenomic/metaproteomic analysis. The results indicated that GAC adsorption still played a major role in removing organic matter once the filters reached a steady-state, which was attributed to bioregeneration, and the contribution of adsorption might be relatively greater than that of biodegradation. GAC with strong adsorption capacity and high bioregeneration potential selected bacterial communities more phylogenetically closely-related than others. The iodine value could be used as an indicator of BAC performance in terms of organic matter removal in the initial stage of the filters, which is dominated by adsorption. However, it could not be used to assess performance at a later stage when adsorption and biodegradation occurred simultaneously. Pore-size distribution characteristics could be chosen as a potential better indicator compared with the current adsorption indicators, dually representing the adsorption performance and the microbial activity, and the proportion of important pore-size of GAC that is more suitable for BAC filter is suggested. GAC with strongly polar terminal groups is more conducive to the removal of ammonium-nitrogen.
生物活性炭（BAC）过滤器在中国和世界范围内被广泛用作高级水处理的重要组成部分。然而，目前尚不清楚如何正确选择 BAC 过滤器中使用的颗粒活性炭（GAC），以及何时需要更换 GAC。在这项研究中，连续运行了 400 天，使用了 5 个 BAC 过滤器，每个过滤器中填充了不同物理化学性质的椰子基或煤基 GAC。通过综合宏基因组/宏蛋白质组分析，研究了 BAC 过滤器中微生物群落的结构和功能以及特定酶的数量。结果表明，一旦过滤器达到稳定状态，GAC 吸附仍然在去除有机物方面发挥主要作用，这归因于生物再生，吸附的贡献可能相对大于生物降解。具有较强吸附能力和较高生物再生潜力的 GAC 选择了与其他 GAC 更具系统发育相关性的细菌群落。碘值可作为 BAC 过滤器在初始阶段（以吸附为主）去除有机物性能的指标。然而，在吸附和生物降解同时发生的后期阶段，不能使用碘值来评估性能。与当前的吸附指标相比，孔径分布特征可以作为一个潜在的更好的指标，同时代表吸附性能和微生物活性，并且建议选择更适合 BAC 过滤器的 GAC 的重要孔径比例。具有强极性末端基团的 GAC 更有利于去除氨氮。
