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Ref No. [UMCES[CBL 11-020
8
Trial # 6 -
Pre filter 20µm > pre filter 10µm > pre filter 5µm > Filter #5, 0.1µm, 20 Jan 2011
PC (mg/L)
DOC (mg/L)
TOC (mg/L)
Time Point
Sample ID
Sample Time
Avg
Avg
(PC + DOC)
T-0 Initial
CW
9:08
2.35
3.23
5.57
T-1 Mid
CW
9:54
2.07
3.25
5.32
T-2 Final
CW
10:34
1.79
3.07
4.86
4.5. Filter Life
In summary, both the membrane filters (PTFE and asymmetric polysulphone) were
effective for extended periods when water was pre-filtered at 20 µm. However, pre-filtration
below 20 µm had no detectable effect on filter life. In general, the asymmetric polysulphone
filter membrane lasted longer than the PTFE filter membrane in all trials but changes in ambient
water quality from trial to trial also influence filtration life.
4.6. Phytoplankton 10 - 50 µm and 5 - 10 µm
Overall phytoplankton conditions and densities were similar between trials. Cell density
was very high and the tests occurred during a winter bloom of both
Skeletonema
and
Heterocapsa rotundatum
. Chains of
Skeletonema
were quite long, and some were noted to be in
the reproductive phase by presence of auxospores.
H. rotundatum
was also experiencing a winter
bloom noted by high density in the samples and distinctive color and odor of the sample water.
Dominant species
Type
General Size
Skeletonema costata
Diatom (chain forming)
Individual cells 9-10 µm but
forms long chains 100+ µm in
length
Heterocapsa rotundatum
Dinoflagellate
~5-6 µm
Other noted species
Prorocentrum minimum
Dinoflagellate
22 x 15 µm
Heterocapsa triquetra
Dinoflagellate
24 x 16 µm
Ceratulina pelagica
Diatom (chain forming)
100 x 24 µm (can form larger
chains)
Gyrodinium estruariale
Dinoflagellate
15 x 11 µm
Thalassiosira sp.
Diatom (chain forming)
Individual cells 8-12 µm
Amphora sp.
Diatom
8 x 30 µm
Leptocylindrus minimum
Diatom (chain forming)
2 x 30 µm (very long and thin)
Navicula sp.
Diatom
Varies 64 µm
Nitzschia sp.
Diatom (chain forming)
Varies 50 to 100+ µm
Chaetoceros sp.
Diatom (chain forming)
Individual cells 7-15 µm
Thalassionema sp.
Diatom (chain forming)
3 x 40 µm forms star patterns
Misc. Tinntinnids
Polychaete larvae
(Zooplankton)