Exopolymeric secretions in HABs : How flow, diffusion and bioengineering may depend on length scale (as well as on rheology, turbulence, behaviour, chemistry,

Exopolymeric secretions in HABs :

How flow, diffusion and bioengineering may depend on length scale

(as well as on rheology, turbulence, behaviour, chemistry, surface properties at membranes, etc)

Ian R. Jenkinson Tim Wyatt

Agence de Conseil et de Recherche Océanographiques,19320 La Roche Canillac, France.

[email protected]

Consejo Superior de Investigaciones Cientificas,Instituto de Investigaciones Mariñas36208 Vigo, [email protected]

Two vessels with exit holes of radius R

Dry powder of grain“radius” rr << R/5


r >> R/5

Dry powder of grain“radius” rR << 5r


R >> 5r

X Clogs

(Jams)Flows

Vessel with exit hole of radius R


Newtonian liquid


Flows

Newtonian liquid


Assuming no inertial effects

(low Re), flow rate

F ~ /where is hydrostatic pressure and is dynamic viscosity

Flows

Newtonian liquid


Monodisperse liquid or paste

with yield stress Y

Y >> Y <<


Monodisperse liquid or paste

with yield stress Y

Y >> Y <<

X Flows F~-Y)/

GelsF = 0

Summary

1. Hard, dry suspensions (powders, sand, etc.)Summary

1. Hard, dry suspensions (powders, sand, etc.)If hole diameter D >> ~5 . grain diameter, thenmaterial flows.Otherwise is jams however high τ.

Summary


2. Monodisperse materials (liquids, solids, gels...)

Summary


2. Monodisperse materials (liquids, solids, gels...)

Material properties (viscosity, elasticity, yield stress) constant across all length scales.

Summary

3. Suspensions of hard particles (spheres, plates, needles, etc.) in a liquid.

Summary


Like powders and sands, but they impart extra viscosity to that of the liquid, because of Brownian motion and repulsive charges

Summary

3. Suspensions of hard particles (spheres, plates, needles, etc.) in a liquid.Like powders and sands, but they impart extra viscosity to that of the liquid, because of Brownian motion and repulsive charges

4. Suspensions of soft particles and bubbles.

Summary


Like powders and sands, but they impart extra viscosity to that of the liquid, because of Brownian motion and repulsive charges

4. Suspensions of soft particles and bubbles.Same as above, but increasing τ can cause particles or bubbles to yield in the hole.

Summary

5. Suspensions of aggregates, flocs, etc. including soft particles aggregated in matricesof softer aggregates (lumpiness)

Summary


Very complex, but empirically viscosity andyield stress are a negative function of hole size(and probably of length scale in general)

Summary


Very complex, but empirically viscosity andyield stress is a negative function of hole size(and probably of length scale in general)Maybe natural waters are mostly like this, but with aggregates very dilute and tenuous, compared to, say, what we are used to in foodsor industrial reactors.

Summary

Intertidal organic aggregates

AiguillonCove

-

Pertuisd’Antioche

Pertuis Breton

Charente

Pertuis de Maumusson

La Rochelle Ré

Oléron

BrouageMudflat

Marennes-OléronBasin

Sèvre Niortaise

Pertuis SeaPampin Mudflat Fluff obtained

here

10 km

Mud flatswith fluid mud

Mud flatswith intertidalfluff



?? Harmful algae ??



?? Harmful algae ??

Is this alga-rich fluff suffocating young sole ?



?? Harmful algae ??

Is this alga-rich fluff suffocating young sole ?

Between birds andsuffocation?

Didymosphenia geminata invading New Zealand rivers

Pictures received from Christina Vieglais via Diatom-L list

21 August 2006



hY

The

Kasumeter

(Yield stress

viscometer)



The

Kasumeter

But sewage sludge, like pelagic and benthic marine organic aggregates, consist of a hierarchical (quasi-fractal) mixture of exopolymeric flocs, or aggregates

hY

The Kasumeter has been adopted as an EUstandard for measuring the « flowability »of sewage sludges (HORIZONTAL Report No. 21, 2004)



The

Kasumeter

Yield stress of sewage sludge for different sludge concentrations (%) as a function of tube diameter. (Drawn from data in Spinosa and Lotito (2003) Adv. env. Res. 7:655-659).

hY



Yield stress of sewage sludge for different sludge concentrations (%) as a function of tube diameter. (Drawn from data in Spinosa and Lotito (2003) Adv. env. Res. 7:655-659).

Y ~ d-2

The

Kasumeter

hY

Rheosole ichthyoviscometerJenkinson, Claireaux and Gentien, (2006) Mar. Biol., in press and published online

It gets the scales and measurement geometry right

Procedure:• A dead sole is arranged so that the tap nozzle fits in its mouth• Test material flows from SR to LR through a tap, into the mouth and through the gills of the dead sole• As the material flows, the hydrostatic pressure difference, H(t) (~water level difference) between the water in each cylinder is measured using a pressure probe, and recorded on computer every 0.5 s.

Rheosole ichthyo-viscometerPlots of hydrostatic pressure difference P vs. time t, obtained with the ichthyoviscometer.

P increased by 10 Pa

Pure seawaterLog-lin

Pure seawaterLin-lin

50% fluff [POM]=(8.4 g.L-1)Lin-lin

1 cm water ~ 100 Pa

50% fluff [POM]=(8.4 g.L-1)Log-lin

Rheosole ichthyo-viscometerPlots of hydrostatic pressure difference P vs. time t, obtained with the ichthyoviscometer.

P increased by 10 Pa

Pure seawaterLog-lin

Pure seawaterLin-lin

50% fluff [POM]=(8.4 g.L-1)Lin-lin

1 cm water ~ 100 Pa

50% fluff [POM]=(8.4 g.L-1)Log-lin

Straight line for log(Y) vs t

Juvenile sole (25 g)can produce a cross-gill hydrostatic pressure P of ~30 Pa

So if Y > P they can'tventilate

Rheosole ichthyo-viscometer

From Žutić and Svetličić in CIESM, 2006, Workshop Monograph N° 28(Cambados)

Adriatic – artist's impression

Mucus event in Adriatic, 1983. Giant mucus streamer in 5 m depth.

Field of view approx. 8 m2 (Stachowitsch, 1984)

Adriatic: Normal appearance of benthos, 1983 (Stachowitsch, 1984)

Adriatic: Mare sporco mucus event, 1983. Sponge with mucus cover, and entangled crab. (Stachowitsch, 1984)

J. Plankt. Res., 17: 2251-2274 (1995)

Viscous modulus(µPa) (Viscosity at shear rate = 1/s)measured in aCouette rheometer

Mitigation of cytotoxicity, rheotoxicity and fish mortality caused by two species of

Gymnodinium

Ian R. Jenkinson, ACRO, Franceand Geneviève Arzul, IFREMER, France

HAB 2000, Hobart, 2000

Seabass: Seawater

0.1

1

10

-50 0 50 100 150 200 250 300

Water height difference(cm). Note log scale.

Pure seawater

1 cm water ~

100 Pa

t (s)

Pure seawater

1 cm water ~

100 Pa

Seabass: G. mikimotoi (Origin: Tinduff, France)

0.1

1

10

-500 0 500 1000 1500 2000 2500 3000

Time (s)

Waterheight diff .(cm) Notelog scale

1 cm water ~

100 Pa

Quasi yield-stress behaviour

“Error” bar is SD n = 3

Yield strength (cm water) of seawater and cultures before and after treatments (second batch of experiments)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

Yield strength (cm water)

G. mik + 0.01mM AC

G. mik + 0.1mM AC

G. mag (10,000/mL)

G. mag+ 0.01mM AC

G. mag + 0.01mM EC

G. mik (23,000/mL)


0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5


G. mik + 0.01mM AC

G. mik + 0.1mM AC

G. mag (10,000/mL)

G. mag+ 0.01mM AC

G. mag + 0.01mM EC

G. mik (23,000/mL)







0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5


G. mik + 0.01mM AC

G. mik + 0.1mM AC

G. mag (10,000/mL)

G. mag+ 0.01mM AC

G. mag + 0.01mM EC

G. mik (23,000/mL)






POM ~Order 1-5 mg.L-1

Y is comparable in the intertidal fluffand in the Karenia mikimotoi culture,but the K.mikimotoi culture is around 1000 times less concentrated in POM

=

Karenia mikimotoitrapped intheir mucusin a 200µmnet.

The mucussticks to, and clogsa plankton net, but notfish gills.

-4

+3L

og k

olm

ogor

ov L

(m

)

Log rms shear rate (s -1) -4 +3

with 0.5 mm bubbles

With 0.1 mm bubbles

North Sea water

(off Heligoland)

Mediterranean water (off Villefranche)

newtonian

Redrawn from Jenkinson (1993) Oceanol. Acta, 16: 317-334

But what aboutlength-scale dependenceof the rheological properties ??

-4

+3L

og k

olm

ogor

ov L

(m

)

Log rms shear rate (s -1) -4 +3

with 0.5 mm bubbles

With 0.1 mm bubbles

North Sea water

(off Heligoland)

Mediterranean water (off Villefranche)

newtonian

Redrawn from Jenkinson (1993) Oceanol. Acta, 16: 317-334

The amount and timing of exopolymer production bydifferent algae is found to be extremely variable, both in culture and in the field: it's hard to deduce generalrules.

Some allelopathic algae may be using the changes in diffusion induced by exo-slime to reduce wastage ofallelopathic substances, and help deliver them to their targets

Cysteine

Presented at HAB2000 (Hobart)

Please note it down now !

The Fourth Plankton Symposium PS IV&

Congresso Brasileiro de Pláncton

01 – 05 APRIL 2007

JOÁO PESSOA, BRAZIL

http://planktonsymposium.web.ua.pt

Exopolymeric secretions in HABs : How flow, diffusion and bioengineering may depend on length scale (as well as on rheology, turbulence, behaviour, chemistry,

Documents

exit hole of radius

suspensions of soft

exit holes of radius

dry suspensions powders

suspensions of aggregates

grain diameter

hole diameter d

yield stress y y y