...
Sludge
...
Blanket
...
Results
...
At
...
the
...
end
...
of
...
June
...
2008
...
an
...
inline
...
turbidity
...
meter
...
was
...
installed
...
to
...
compare
...
the
...
floc
...
formation
...
in
...
the
...
floc
...
blanket
...
tank
...
to
...
the
...
results
...
coming
...
for
...
the
...
tube
...
settlers
...
at
...
the
...
end
...
of
...
the
...
flocculator.
...
The
...
turbidity
...
meter
...
was
...
set
...
up
...
to
...
draw
...
samples
...
from
...
the
...
plant
...
leveling
...
tank
...
set-up
...
after
...
the
...
launder
...
out
...
of
...
the
...
sludge
...
blanket
...
tank.
...
After
...
this
...
set
...
up
...
was
...
completed
...
the
...
tank
...
was
...
run
...
at
...
up-flow
...
velocities
...
of
...
30,
...
50,
...
70,
...
and
...
100
...
m/day.
...
At
...
all
...
of
...
these
...
velocities
...
the
...
tube
...
settlers
...
out
...
of
...
the
...
flocculator
...
performed
...
better
...
than
...
sludge
...
blanket
...
removal system. Graphs of the outlet turbidity versus time for the sludge blanket tank and the final tube settler in the flocculator can be seen below.
| Wiki Markup |
|---|
{float:right|border=2px solid black|width=200px} {anchor:30mperday}[!Pilot Plant - Flocculator Research^30mday_smallG.jpg|width=200px!|Pilot Plant - Flocculator Research^30mday_smallG.jpg] h5.Comparison of Results from system. Graphs of the outlet turbidity versus time for the sludge blanket sedimentation tank at 30 m/day and the finala tube settler inplaced at the flocculatorend canof bethe seen belowflocculator. {float} |
At
...
30
...
m/day
...
there
...
was
...
very
...
little
...
suspension
...
of
...
the
...
floc
...
blanket,
...
it
...
was
...
mostly
...
settled
...
sludge.
...
All
...
floc
...
that
...
weren't
...
heavy
...
enough
...
to
...
settle
...
on
...
their
...
own
...
rose
...
through
...
the
...
tank
...
and
...
exited
...
the
...
tank
...
through
...
the
...
launder. (To examine a larger picture of the graph, please click on the graph to the right)
| Wiki Markup |
|---|
{float:right|border=2px solid black|width=200px} {anchor:30mperday50mperday}[!Pilot Plant - Flocculator Research^30mdayResearch^50mday_smallG_correct.jpg|width=200px!|Pilot Plant - Flocculator Research^30mdayResearch^50mday_smallG_correct.jpg] h5.Comparison of Results from the sludge blanket sedimentation tank at 3050 m/day and a tube settler placed at the end of the flocculator. {float} \\ \\ At 50 |
At 50 m/day
...
the
...
tank
...
performed
...
decently.
...
A
...
good
...
floc
...
blanket
...
formed
...
in
...
the
...
tank
...
and
...
as
...
long
...
as
...
the
...
blanket
...
was
...
kept
...
a
...
few
...
inches
...
below
...
launder.
...
The
...
suspension
...
was
...
thick
...
and
...
fairly
...
stratified,
...
thicker
...
at
...
the
...
bottom
...
and
...
progressively
...
thinner
...
closer
...
to
...
the
...
top.
...
Still
...
some
...
fairly
...
decently
...
sized
...
floc
...
were
...
escaping
...
to
...
the
...
top.
...
It
...
was
...
suspected
...
that
...
this
...
flow
...
rate
...
was
...
too
...
low
...
and
...
that
...
the
...
shear
...
in
...
the
...
blanket
...
could
...
possibly
...
be
...
breaking
...
up
...
flocs.
...
This
...
was
...
a
...
suspicion
...
that
...
was
...
difficult
...
to
...
prove.
| Wiki Markup |
|---|
{float:right|border=2px solid black|width=200px} {anchor:50mperday70mperday}[!Pilot Plant - Flocculator Research^50mdayResearch^70mday_smallG_correct.jpg|width=200px!|Pilot Plant - Flocculator Research^50mdayResearch^70mday_smallG_correct.jpg] h5.Comparison of Results from the sludge blanket sedimentation tank at 5070 m/day and a tube settler placed at the end of the flocculator. {float} \\ \\ At 70 |
At 70 m/day
...
the
...
sludge
...
blanket
...
was
...
thinner
...
than
...
at
...
50
...
m/day
...
but
...
still
...
well
...
developed
...
and
...
thick
...
at
...
the
...
bottom.
...
The
...
floc
...
rising
...
through
...
the
...
blanket
...
were
...
about
...
the
...
same
...
size
...
as
...
the
...
in
...
the
...
50
...
m/day
...
tank
...
and
...
the
...
results
...
were
...
in
...
consistent.
...
Sometimes
...
better
...
than
...
the
...
50
...
m/day
...
but
...
also
...
worse.
At 100 m/day the blanket was stratified and well formed but much thinner toward the top in comparison to the 50 m/day tank. The floc that were rising up through the tank were much smaller than at the other velocities suggesting that there was less shear in the blanket at this higher velocity and that flocs were not being broken up and rising through the blanket. The 100 m/day velocity needs to be re run to confirm the low shear theory given that changes were made to the flocculator during the testing of various velocities.
These results show that a sludge blanket alone is not as effective a method for settlement removal as the lamella simulated by the tube settlers. Thus now it is being explored if results can be improved by combining the technologies of sludge blankets and lamella.