The to move water to ”Consorci d’Aigues de

The research that relates biofilm
structure to dissolved organic carbon was carried out by Romani, et al., (2004). In this study, the
regions surrounding the Ebro River located at the Iberian Peninsula was used as
the sampling location. The river possesses an annual mean discharge around 499m3s-1.
As a result of its location, water velocity within the river is often very low
during summer. A distance of at least 50km from Ebro River was used as the
exact sampling location. This is the area where the river water changes its
course and is diverged to two distinct points for the purpose of irrigation. From
one of the irrigation pathways, a pipe is used to move water to ”Consorci
d’Aigues de Tarragona” (CAT), a treatment plant. Four sampling point C1, C2,
P1 and P2   located at the beginning and at the end of the
open channel of the river as well as at the beginning and at the end of the
pipe respectively.

A small glass material with surface
area of about 1 cm2 was buried at all the sampling point for 60days
so that biofilms can develop on glass surface. The experimental set up ensured
that the flow of water ran parallel to each substratum. The surfaces were
retrieved in September 2000, November 2000, May 2001, and July 2001
respectively for structural analysis. Water sampling was done during this time
up until November 2001 (some 5months after retrieval of glass surfaces from the
different sampling points. This was to ensure measurement of dissolved organic
carbon as well as some chemical and physical parameters. The possibility of algae
density in water as well as extracellular enzyme activities was checked by
carrying out water sampling from P2 and C2 (November 2001 and April 2002
respectively). In addition, 14C-glucose uptake and DOC uptake and/or
release rates in microcosm incubations was done on retrieved glass surfaces
takes in April 2002, structure and function of biofilm was also checked at this
time. Other measured carried out includes; Particulate organic carbon (POC),
river DOC and BDOC budget, Extracellular Enzyme Activity, Chlorophyll Density.
C and N Biofilm Content among other things.