Microbial community of the initial stage of biologically active carbon filters’ work and its role in organic matter removal from water

Abstract

Filtration through biologically active carbon (BAC) filters is an effective method of organic matter removal during drinking water treatment. In this study, the microbial community in the initial period of filters’ operation, as well as its role in the organic matter removal were investigated. Research was carried out in a pilot scale on two BAC filters (Filter 1 and Filter 2) which were distinguished by the type of inflowing water. It was observed that the number of heterotrophic plate count bacteria and total microbial activity were significantly higher in water samples collected from Filter 2, which received an additional load of organic matter and microorganisms. Despite the differences in the values of chemical and microbiological parameters of inflowing water, the composition of the microbiome in both filters was similar. The predominant taxon was a bacterium related to Spongiibacter sp. (Gammaproteobacteria) (>50% of relative abundance). In both filters, the efficiency of organic matter removal was at the same level, and the composition and relative frequency of predicted functional pathways related to metabolism determined using PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States Software) at level 3 of KEGG (Kyoto Encyclopedia of Genes and Genomes) Orthology – were also similar. The study demonstrated that a 40-day period of filter operation after filling with virgin granular activated carbon, was sufficient to initiate biofilm development. It was proved, that during the initial stage of filter operation, microorganisms capable of biodegradation of various organic compounds, including xenobiotics like nitrotoluene, colonized the filters

Keywords

• biofilm formation
• drinking water
• biodegradation
• biologically active carbon filters
• picrust analysis
• 16s rrna-profiling