Dm. Moll et al., Impact of temperature on drinking water biofilter performance and microbial community structure, ENV SCI TEC, 33(14), 1999, pp. 2377-2382
Citations number
48
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Seasonal changes in removal of natural organic matter (NOM) by drinking wat
er biofilters are often attributed to temperature differences. Bench-scale
sand biofilters treating NOM isolated from a surface water source were oper
ated in parallel at 5, 20, and 35 degrees C to isolate the effect of temper
ature from other water quality and operational parameters, which also vary
seasonally. The biofilter operated at 5 degrees C achieved significantly lo
wer removal of NOM and the NOM fraction that reacts with disinfectants (dis
infection byproduct precursors) compared to the filters operated at 20 and
35 degrees C, which had similar performance levels. Viable biomass, measure
d as lipid phosphate, was significantly higher at the top and bottom of the
! filter operated at 20 degrees C. Phospholipid fatty acid (PLFA) profiles
indicated an increasing gradient in markers for Gram-negative bacteria and
microeukaryotes as biofilter operation temperature decreased, replacing gen
eral fatty acids and markers for Gram-positive bacteria and sulfate-reducin
g bacteria, which were observed in greatest abundance in the filter operate
d at 35 degrees C. Principal components analysis differentiated the microbi
al PLFA profiles based an biofilter operation temperature and filter depth.
These results were corroborated by identifications of the dominant microbi
al colonies isolated on R2A agar.