Performance of direct biofiltration of surface water for reduction of biodegradable organic matter and biofilm formation potential
Artikel i vetenskaplig tidskrift, 2006

Direct biofiltration of surface water may be considered as pre-treatment for membrane filtration, in order to reduce fouling. The biofiltration process was investigated with regard to biodegradable organic matter and biofilm formation, covering the annual variations under moderately cold climate conditions. Granular activated carbon (GAC) and two types of crushed expanded clay (EC) were compared as filter media. To assess the biological properties of the biofilters, viable biomass and respiratory activity was examined. Biofiltration removed assimilable organic carbon (AOC) and biodegradable dissolved organic carbon (BDOC) by about 30% and also reduced the bacterial concentration in the water phase. Also, biofilm formation in the treated water was reduced by 80-90% during summer and winter conditions. The reductions in the investigated parameters were similar in the biofilters with GAC and EC. Likewise, a similar amount and development of biomass was found in the GAC and EC biofilters of comparable grain size with a pronounced stratification from top to bottom of the filter bed. The specific respiratory activity of the biofilter biomass was dependent on raw water temperature. Even though slight correlations between BDOC removal and temperature or respiratory activity were observed, AOC and BDOC removals were mainly dependent on the feed water concentrations of these compounds. The results indicate that direct biofiltration of surface water, by reducing AOC, BDOC and biofilm formation in the water, may be an advantageous pre-treatment for membrane filtration processes.

PRE-TREATMENT

DRINKING WATER

BIOFILM FORMATION

BIODEGRADABLE ORGANIC MATTER

BIOFILTRATION

FILTER MEDIA

Författare

Frank Persson

Göteborgs universitet

G. Heinicke

W. Uhl

Torsten Hedberg

Chalmers, Bygg- och miljöteknik, Vatten Miljö Teknik

Malte Hermansson

Göteborgs universitet

Environmental Technology (United Kingdom)

0959-3330 (ISSN)

Vol. 27 1037-1045

Ämneskategorier

NATURVETENSKAP

PubMed

17067130