3 Storage and Detoxification of Bivalve Molluscs as a Tool in a Marketing Strategy
31
0
20
40
60
80
100
120
140
160
180
200
0
50
100
150
200
Time (min)
Flow rate across the filter (L.h -1
.m -2
)
H. triquetra
A. minutum
P. lima
Fig. 3.2 Flow rates during membrane micro-filtration (0.2 m) of three micro-algal suspensions
at 30,000 cells.mL
1 H. triquetra, A. minutum, P. Lima (control) and Skeletonema costatum
continuous supply (trial)
particle rejection rate over time. Filtration rates obtained with this grain size could
be increased by the use of filters placed in series. The best retention, 99 % after 4.5 h
of filtration, was obtained with the finest sand, which had a grain size ranging from
26 to 496 m. It was also noted that the appearance of micro-algae in the treated
water was delayed when bed thickness was increased (Sabiri et al. 2011).
For membrane filtration, 99 % of the micro-algae were retained regardless of
whether the suspension consisted of A. minutum, H. triquetra or P. lima cells, and
independent of cell concentration (1,000 or 30,000 cells.mL
1 ) (Castaing et al.
2010). In the case of sand filtration of A. minutum, H. triquetra and P. lima
suspensions at 30,000 cells.mL
1 , the flow rate decreased during the first hour of
filtration, then stabilized (Fig. 3.2). Membrane fouling depended on the micro-algal
species and compounds present in the supernatant, and was mainly due to organic
compounds (Castaing et al. 2011). In addition, mixing diatoms (1,000 cells.mL
1 )
with toxic algae to mimic natural populations did not significantly modify the
observed drop in flow rates.
Phycotoxin Stability and Bioavailability
SEM observations of cells caught on either sand or membrane filters unambiguously
demonstrated that cell walls were broken and that, as a consequence, intracellular
31
0
20
40
60
80
100
120
140
160
180
200
0
50
100
150
200
Time (min)
Flow rate across the filter (L.h -1
.m -2
)
H. triquetra
A. minutum
P. lima
Fig. 3.2 Flow rates during membrane micro-filtration (0.2 m) of three micro-algal suspensions
at 30,000 cells.mL
1 H. triquetra, A. minutum, P. Lima (control) and Skeletonema costatum
continuous supply (trial)
particle rejection rate over time. Filtration rates obtained with this grain size could
be increased by the use of filters placed in series. The best retention, 99 % after 4.5 h
of filtration, was obtained with the finest sand, which had a grain size ranging from
26 to 496 m. It was also noted that the appearance of micro-algae in the treated
water was delayed when bed thickness was increased (Sabiri et al. 2011).
For membrane filtration, 99 % of the micro-algae were retained regardless of
whether the suspension consisted of A. minutum, H. triquetra or P. lima cells, and
independent of cell concentration (1,000 or 30,000 cells.mL
1 ) (Castaing et al.
2010). In the case of sand filtration of A. minutum, H. triquetra and P. lima
suspensions at 30,000 cells.mL
1 , the flow rate decreased during the first hour of
filtration, then stabilized (Fig. 3.2). Membrane fouling depended on the micro-algal
species and compounds present in the supernatant, and was mainly due to organic
compounds (Castaing et al. 2011). In addition, mixing diatoms (1,000 cells.mL
1 )
with toxic algae to mimic natural populations did not significantly modify the
observed drop in flow rates.
Phycotoxin Stability and Bioavailability
SEM observations of cells caught on either sand or membrane filters unambiguously
demonstrated that cell walls were broken and that, as a consequence, intracellular