Berliner Wasserbetriebe, Neue Juedenstr. 1, 10179 Berlin, Germany.
Chair of Environmental Microbiology, Institute of Environmental Technology, Technische Universität Berlin, Ernst-Reuter-Platz 1, 10587 Berlin, Germany.
Sci Total Environ. 2023 Jan 15;856(Pt 2):159265. doi: 10.1016/j.scitotenv.2022.159265. Epub 2022 Oct 5.
Ozonation is an established solution for organic micropollutant (OMP) abatement in tertiary wastewater treatment. Biofiltration is the most common process for the biological post-treatment step, which is generally required to remove undesired oxidation products from the reaction of ozone with water matrix compounds. This study comparatively investigates the effect of filter media on the removal of organic contaminants and on biofilm properties for biologically activated carbon (BAC) and anthracite biofilters. Biofilms were analysed in two pilot-scale filters that have been operated for >50,000 bed volumes as post-treatment for ozonated wastewater treatment plant effluent. In parallel, the removal performance of bulk organics and OMP, including differentiation of adsorption and biotransformation through sodium azide inhibition, were carried out in bench-scale filter columns filled with material from the pilot filters. The use of BAC instead of anthracite resulted in an improved removal of organic bulk parameters, dissolved oxygen, and OMP. The OMP removal observed in the BAC filter but not in the anthracite filter was based on adsorption for most of the investigated compounds. For valsartan, however, biotransformation was found to be the dominant pathway, indicating that conditions for biotransformation of certain OMP are better on BAC than on anthracite. Adenosine triphosphate analyses in the media-attached biofilms of the pilot filters showed that biomass concentrations in the BAC filter were significantly higher than in the anthracite filter. The microbial communities (16S rRNA gene sequencing) appeared to be similar with respect to the types of organisms occurring on both filter materials. Alpha diversity also exhibited little variation between filter media. Beta diversity analysis, however, revealed that filter media and bed depth substantially influenced the biofilm composition. In practice, the impact of filter media on biofilm properties and biotransformation processes should be considered for the design of biofilters.
臭氧氧化法是一种成熟的方法，可用于三级废水处理中的有机微量污染物（OMP）去除。生物过滤是生物后处理步骤中最常见的工艺，通常需要从臭氧与水基质化合物反应的产物中去除不需要的氧化产物。本研究比较了两种过滤介质对生物活性炭（BAC）和无烟煤生物滤池去除有机污染物和生物膜特性的影响。在两个中试规模的过滤器中对生物膜进行了分析，这些过滤器已作为臭氧处理后废水处理厂出水的后处理运行超过 50,000 个床体积。同时，在填充来自中试过滤器材料的台式过滤柱中进行了批量有机物和 OMP 的去除性能研究，包括通过叠氮化钠抑制作用区分吸附和生物转化。与无烟煤相比，使用 BAC 可改善对有机总体参数、溶解氧和 OMP 的去除。在 BAC 过滤器中观察到但在无烟煤过滤器中未观察到的 OMP 去除主要基于吸附，对于大多数研究化合物而言。然而，对于缬沙坦，发现生物转化是主要途径，这表明对于某些 OMP 的生物转化，BAC 的条件比无烟煤更好。在中试过滤器的介质附着生物膜中进行的三磷酸腺苷分析表明，BAC 过滤器中的生物量浓度明显高于无烟煤过滤器。就两种过滤材料上发生的生物类型而言，微生物群落（16S rRNA 基因测序）似乎相似。α多样性在过滤介质之间也表现出很小的变化。然而，β多样性分析表明，过滤介质和床深对生物膜组成有很大影响。在实践中，对于生物滤池的设计，应考虑过滤介质对生物膜特性和生物转化过程的影响。
