Impact of upstream chlorination on filter performance and microbial community structure of GAC and anthracite biofilters

摘要: Drinking water filters may be operated to promote or deter biological activity through upstream oxidant addition. While there are several quality benefits from biofiltration, microbial growth in biofilters warrants further investigation. In this study, routine monitoring detected target DNA sequences for Naegleria fowleri source and Acanthamoeba spp. biofilter effluent, triggering community characterization. Full-scale anthracite granular activated carbon (GAC) receiving chlorinated waters were compared terms of effluent (i.e., turbidity particle counts), adenosine triphosphate (ATP)), the composition 16S/18S rRNA gene sequencing, free-living amoeba). Because rapid chlorine quenching by GAC, greater biomass development was observed GAC (ATP = 5 × 103–5 104 pg cm−3 media) than filter 4 102–1 103 media). Due possible sloughed biomass, also had consistently turbidity, counts, cellular ATP filter. 16S sequencing revealed distinct taxonomic differences between filters, hosted a more diverse population (Shannon index: 3.7–5.0 2.4–2.9). At genus level, contained mostly Undibacterium-like taxon (45–68%), while dominated Massilia (8–36%), Herbaspirillum (2–44%), unknown Comamonadaceae (9–18%), among others. The presence viable amoebas media. Further characterization eukaryotic 18S showed that predominantly harbored copepod Leptodiaptomus (67%), majority unknown.