Nanoporous alumina membranes

Nanoporous alumina membranes

Research Trends membranes contact membrane concentration liquids of is ethylene cell, from The and effective concentration glycol is negl...

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Research Trends

membranes

contact

membrane

concentration liquids

of

is

ethylene cell,

from

The

and

effective

concentration

glycol is negligible,

compared

the

temperatures

both computer them

values were obtained

unusual

behaviour

appeared

that the lactone

by a difference the

This of the

in

concentration

of the pervaporation

separation

polypropylene

code,

for the permeability

of the

the outside

coefficients

of the boundary

sulfate

(1. Rincirn,

J.M. Ortiz

/. Membrane

of other

literature

de Zgrate,

J.I. Mengual:

chemical

experiments - covering

properties,

low-boilers

with from

at 300°C

aqueous

organophilic

A model,

membranes

estimation

of

trans.membrane

coefficients

(with

a driving

pressure

between

the influence

of the

pressure

on the selectivity

total

membrane

set,

extraction was

containing that

03

selective the

most

was

carried

the

SDS

water-system

having

proved

low-boiler, series on

of

unfilled

module

by using dextran

ultrafiltration

liquid

enhanced

can be achieved namely

were

ultrafiltration

their

angle.

flow,

critical

pore

permeate

earlier to the TCEto the TCE-

wetted

pore

and

the inclined T.-W.

tubular

Membrane

i5

of the of the

53”

in

the

here.

The

about

of natural induced

Cheng,

flux

angle

in tlux is brought

convection

with

up to a certain

inclination

effects

the

system

increases

optimal

combination forced

resistances-in-series

by the

convection

and

by the slug flow in

membrane.

H.-M.

Yeh,

Science 158(1-2)

J.-H.

Wu:

221-234

1.

(1 June

1999). 187-209

(1 June

microfiltration of successive operating

z~; / at constant

(MF) performance.

paid

from

stress,

Z~ at

and /

these successive to

the

Nanoporous

alumina

the

cycles

evolution

of

to skimmed

milk

of trimethylaluminium

vapour

the

Aluminium

conditions.

The

chamber.

in the pores of

reduction

Separation

vapour

in

of the mixture

(water)

and

gas (oxygen)

was performed

unmodified

and modified

membranes

temperature. exhibited

The

CVD-modified

a water/oxygen

the

on the

80%

relative

permeance

at room factor

separation

membranes humidity

with

as

with water

of 6.9 x lo--’ mol/m2sPa.

the maximum

unmodified

nonon the

membrane

separation

high as 71 at 12% relative humidity permeance

the

gases, but not of

condensable

system

hysteresis

vapour.

with

layer. The modification

of non-condensable

condensable

comparison,

The

reaction

a substantial

condensable

vapour

depended

membrane in

permeance

into

(CVD),

oxide was deposited

the y-Al,O, resulted

deposition

by

introduction

water

(0.1 pm

proteins.

layer, on a

was modified

and

of casein

flux which

support,

alternative

membrane

soluble

a-AlzO, vapour

for the separation

ceramic

membranes

4 nm pore y-Al,O,

chemical

of

of the separation.

was applied

a limiting

AII

trans-membrane

selectivity

mean pore diameter)

It and

(A P at constant

AZ’ the

flux. During and

for

cycles of increasing

parameters

This methodology

was used

conditions

ZW; z~, at constant

was

permeability

of

operating

consisted

hydrodynamic

the

In

as the inclination

column

The

enhancement

through

wetted

“cyclic” methodology

crossflow

micelles

ultrafiltration

significantly

angle

slightly.

A. Das, A. Saraf, K.K. Sirkar: _/.

An experimental

showed

flux

two-phase

two-

turbulent

of inclination

permeate

discussed

Crossflow microfiltration skimmed milk

permeation

with

flow, the variation

laminar

solution

gas-liquid

liquid

feed

aqueous

or the

affects gas-liquid

were

membrane

system

dodecyl feed

experiments ceramic

T500

(TCE) as

the

and

flow ratios

In the single, liquid-phase

system,

A sol-gel derived

decreasing

The

in a tubular

system

Science 158( l-2)

evaluate

gas-liquid

angles.

out

gas-slugs

measured

experimental

the

for both

MF using a tubular

feed

inclination

carried

macroporous

to

various

ultrafiltration

1979).

attention

pressure.

and

under

were

surfactant,

Zw the wall-shear

the

discussed

of an inclined

system

phase

on

pore conditions.

Membrane

fluxes

as the tested solution.

a thin

coating

The

has been extended

I. Abou-Nemeh,

permeate

of

applied

,/,

(1 June

flux in tubular

i,< about

pressure,

vapour-liquid

second out

successfully system,

G. Da&n:

column

and ethyl

of the aqueous A

The

for example,

The

and

soluble

211-222

ultrafiltration

pore.

and

E. Boyaval,

Science 158(1-2)

Depending

conditions,

water

cake structure fluxes

performance.

,I) with

operation

hydrophobic

acetate.

studied.

to investigate

constant

membrane

than

of VOCs

a

the fibre bore. The

range

concentration

non-wetted

by

surfactant.

the

molecules,

of the total permeate

characteristic

is ethyl

experiments

two

the silicalite-filled

more

for

(diaceryl

factor of the pervaporation

to be

of small-

used

With

equilibrium

permeate

silicone

separation Moreover,

to

At

acetate).

was independent

each

in order

compounds.

of low-boilers these

in

of the pervaporation

permeants,

pervaporation

the

aroma

for the selective

organic

on

expressed

represent

best-suited

on a plate-

force

was used

a silicalite-filled

of

solutions

transfer

difference

studied

were

from

and SDS concentrations,

a wide

non-wetted

concept -

kinds

based

side of rhe membrane),

of the various

rhe

and

hydrophilic

three

module.

terms of partial

aroma

solutions,

through

and-frame

size

the

Membrane

ultrafiltration

sodium

parameters,

TCE

over

two different

high-boilers

commercial

first.

as

of its

transmission.

Ultrafiltration membranes

microporous

and

because

tl-.ins-membrane

permeation

G. G&an-Guiziou.

The

(PDMS)

was passed through

separation

a wide range of physicoranging

in model binary

over a

1999).

trichloroethylene

contaminant

operating

varied on

four

to very hydrophobic

conducted

the

of VOCs

fibres,

effect on the process

Permeate pressure effects on selectivity

diluted

diameter,

flow-rate,

(1 June

1999).

compounds

protein

model of

the

thi:, ratio.

/. Me&rune

been

silicone

(SDS)

process

155-165

hollow

model

solution

expectations.

Science 158(1-2)

Pervaporation

low

membrane-based

has

high

led to irreversible

to

which

Above

of the deposit, under

then

hydrophobic

plasma-polymerised the

layers. The values

employed

was satisfactory.

1999).

aqueous

process

process

under

pressure,

(I June

hollow-fibre

performance

c.omprcssibility

flux over efficient

(//Taco).

the

operation

recovery

surfactant-conraining composite pervaporation

to take

those

and

stress

the consolidation

Hollow-fibre membrane-based pervaporation The

ratio of permeation

wall-shear

the

prediction

167-185

(such as thickness,

and made it possible to determine

nature

coefftcient

selectivity

specific

in order

agree with

transfer accurate

rhc

dcpos1:

characteristics

compression

of

.~i)our

m1(.ellcs

at each side of

associations,

in

and

the computer

and with theoretical

the

resulted

and for the heat and mass-transfer

sources,

as it

flux was not induced

compound

I. Souchon,

an

asauml,r~irn\ casem

and structure) a critical

permeate

displayed

pressure

Whatever

an

ywere

y-decalactone.

in partial

membrane.

total

membrane with

membrane-aroma

membrane, obtained

I’DMS

the

The

Science 158(1-2)

the

the effects of

From

on

pressure.

and

selectivities

that

hand,

code was developed account.

dependent

cases.

M. Marin:

pressure

were very important,

into

In both

pressure.

employed and

temperature

polarisation

(S-methylthiobutanoate

range of total permeate

with that of water,

On the other

of

A. Baudot,

is achieved.

since the vapour

experiments.

suggested

alteration

reject the glycol,

result ia expected, ar

observed

aroma

different

show

completely

flow

of PDMS

high-boiling

decalactone).

trans-membrane

water-

using a tangential

experiments

almost

coolant

with

membranes

temperatures.

the

distillation

performed

glycol mixtures,

membranes

used

Membrane

were

various

and

glycol

analysed.

experiments

for

distillation

layer composed

with

compounds highly

Separation of water and glycols In this paper the feasibility of using direct-

(&ctive

I’EBAJ

and

was about a water

In

factor for

11 at vapour

of 2.9 X 1O-’ mol/m*sPa.

Membrane Technology No. 115

M. Pan, (:. Cooper. Meng:

Y.S. Lin, G. Y.

Membrmc

.I.

158(1-2)235-241

(1 June

purification.

RO

Sciencr

preferred

1939).

medium-size

1s

process

for

seawater

also

the

E. Drioli,

small-

and

G. Barbieri:

desalination.

F. Lagana,

141L145

A. Criscuoli,

I? Gel&r.

Desalination 122(2-3)

(7 July 1999).

F.U.

Hahncnstein,

Krumm,

‘11 peter\:

122(2-3)

151L15h

U.

Drdi~zatio~~ (7 ]ulv 1999).

Israel is one of the Mediterranean

A dynamic film model for ultrafiltration A

dynamic

that

variation

in

diffusivity,

viscosity

and

has been

developed.

uses

desalination.

to be given to the design

flux

continuity balance

This

model,

the

which

momentum stagnant

assumes

mass-transfer

that

and

dynamic

filtration film of

how

coefficient

of a device

by changes

the

explicitly

mass-transfer is affected

in the feedstock

operating

parameters.

predictions

of the

dynamic

model

were

compared

to experimental of

The

were

measuring

the

P.

flux for

122(2-3)

123-140

Integrated operations processes (RO)

in operation

are

competitive

These to

of thermal

costs are mainly

the

pretreatment

of

In all of these and

by less than

In contrast,

obtained

provides

with

the

differed

by as

from

the

79% Thus

the

in

desalination

be possible,

water

for

bivalent

recovery could

worldwide,

southern

brackish

reverse osmosis suitable

In water

to

are areas

merhod

the of

discussed,

possibility recovery

is

of also

(MI;) can reduce

operating

This

the prepaper

pretreatment

rnicrofiltration

using

membrane capital

and

costs on RO plants

and

is supported from

a

by operational

number

CMF-RO

90%

B.

147-150

of

installations

Durham,

(7

data

worldwide on different

A.

Desalination 122(2-j)

Wilken:

Walton: 157-l 70 (7

July 1999).

might

be the

(MD) brine.

units In

the

integrated

above,

such as the are analysed

desalination

system.

experimental

results

confirming of 87%.

system

of

system

already

a

considerably

pressure-

(PES),

in use in other higher

recovery

which

suited

the

a seawater

PES

larger

than or

that

than

is

2000

production.

It

simple,

variable

discharge

volume,

and has - because

of its design and

direct

transmission

pressure

high-pressure efficiency

of

brine to the feed - an value

of

about

Next

month News

Industry wends

is especially

greater

of

of

pumps

plants,

permeate a

a

efficiency

in reverse osmosis

The for

is

domains,

by using reverse running

98%.

Commercialnews New product releases Contracts

Features Developments and appltcations around the world

From this there results an economic energy

contactors

by introducing

of reaching factor

(for

02)

work,

Preliminary

technologies.

feed sources.

application

adaptation

of the RO process

operations,

ones described

are

gases

possibility

RO

for a seawater

is available,

(RO) is usually

the

membrane

dependent most

treat

of conventional

95% and 98% by

Pressure exchange for RO plants

enables

If the

and

distillation

present

including

Mediterranean,

increasingly

desalination.

of

be

clarifying

Moreover,

membrane

Desi n and operation desa 7ination plants

and

membrane

factor

effectiveness at how

and

July 1999).

turbines.

and for reducing

be enhanced

to

treatment

fouling,

of RO

membranes

and between

(RO) systems may be achieved

(MF),

dissolved

considered.

limited

of rhe sensitivity

variety of sources. This information

water, were

Desalination 122(2-3)

been

also allow RO to be used on a wider

four-valent

R.-D.

Raff,

energy

example,

the RO treatment

Reis: 1. Membrane Science 158( 1-2) 1999).

of

introducing before

R. van

By

ions concentration.

the

S. Saksena,

reach

pretreatment

purifying

suggested,

processes.

between

m3/d

line

the

as

been

particularly

have

technology

the

U02(C03)~~,which

four membranes

approximately

the feed streams

--

complex

occur in natural

(NF) units might

CO?

the

and

(UF) and eventually

example

of

UO,(CO,)‘;

ultrafiltrarion

removal

a significantly

anion

By

For

the

water

particular,

such have

and waste-water.

applicariona.

waste-water,

looks

carbonate

divalent

exchange

with an increase

in

natural

In

nanofiltration introduced

are

for uranium

hydrogen

for

microfiltration

mass-transfer dynamic

in

that

sea water (SWRO)

because

settings

complexes

complexes.

the

costs.

quality.

crossflow

model

allow uranium

important

mobilisation

of

might

overall

the

description

Perkins,

might

those

most

which

costs

steps,

of

which

(RO)

already

with those

operations. related

water

reduction

effect

to form

0.

costs for

and brackish

were

different

technologies

osmosis

The

and 93% by one membrane.

for desalination

The operating

seawater

235-241 (1 June

most

plants

reverse

a possible

experimental

on

many

operations,

‘IS

where

are

using

pre-treatment

used for more than 20 years to treat

five

flat-sheet

Hydro-chemical

mainly

at several feed flowthe

waters.

rejected

there

of

Experiments

out

reverse

efficiency

water

nanofiltration

carried

the

filtration to evaluate

removal

drinking

anion complex

membrane

much

becoming

membrane in desalination

integrated

film model

the

(7 July 1999).

introducing

mass-transfer

areas

Desalination

Glueckstern:

both

uranium

uranyl

analysed.

were

stagnant

Many

and

studies

I 1% on average.

T.W.

to

are also reviewed

desalination

in

predicted

ultrafiltration

costs

the

were chosen

aimed an.2

60%

differed

film model

further

4 to

experimental

enhanced

lower

and

reliability,

membrane was operated

membranes. is

from

velocity.

coefficients.

improvement<

improving

obtain

seawater

the

values

technological at

Membrane

different

the

trends for

Plate-module equipment

with systems

perspectives

Membrane for RO

from

bulk

to investigate

fitted

New

An

Removal of dissolved uranium by nanofiltration

currently to

low-cost

presented.

processes.

pressure

ranging

coefficients

and

all over the world

by

with

14 g/l. The filtration

tangential

reliable

applied

osmosis

solute

variation

concentrations

CXC.S.

in Israel along criteria

plants

film

evaluated

solution5

repeated

areas.

operating design

has

of plants

remote

The

data for of

trans-membrane

then

in

of the

Today

a monoclonal

effects

concentration

operating

attention

overview

and

systematically

filtration

antibody.

rates

rate,

Special

approach

a means

MAb

is solute

predicting

with

the

coefftcient

concentration

the

film

of

provides

of

over a boundary the

independent the

model

equations

and

Unlike

velocity

approximate

equation

layer.

with

solution

the

and for seawater

for

tangential

to

RO is solely used,

the

Pohlhausen’s

solution

where

for brackish

model

solvent

solute

both

describes

film

ultrafiltration

countries

recovery,

and

amortisation

times for such systems from 2-4 place

years, depending

of operation.

are presented paper:

The

industry

with individual example

with

in the PES

in

with pressures in RO systems

and parallel of

d emonstration

trains;

Patents World, USand European membrane patents

and design of a

system

for

MetScope The best membrane sites

a demonstration

system; and concept existing

Latest membrane research

4 and 16 MPa; conception

of the application an

ResearchTrends

following

details of the PES;

experience

the mining

vary

on the

and explained

technical

practical between

which

reviewed

a”

RO plant.

Membrane Technology No. 115