Recent Applications of Dynamic Membranes - American Chemical

24 Recent Applications of Dynamic Membranes C R A I G A . B R A N D O N — C A R R E , Inc., Seneca, SC 29678

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on June 2, 2015 | http://pubs.acs.org Publication Date: May 27, 1981 | doi: 10.1021/bk-1981-0154.ch024

J. L E O GADDIS—Department of Mechanical Engineering, Clemson University, Clemson, SC 29631 H . G A R T H SPENCER—Department of Chemistry, Clemson University, Clemson, SC 29631

The systematic i n v e s t i g a t i o n o f dynamically-formed membranes began w i t h t h e formation of a salt r e j e c t i n g membrane in 1965 at the Oak Ridge N a t i o n a l Laboratory. ( l ) The dynamic hyperfiltration membrane most o f t e n used in subsequent a p p l i c a t i o n s has been prepared by s e q u e n t i a l d e p o s i t i o n s o f zirconium IV hydrous oxide f o l l o w e d by poly(acrylic acid) on a s u i t a b l e porous support under pressure and cross f l o w c o n d i t i o n s . Although not competitive w i t h t h e conventional hyperfiltration membranes f o r desalination, the resulting hyperfiltration (RO) membrane possesses p r o p e r t i e s d e s i r e d f o r some industrial a p p l i c a t i o n s . (2) It is s u i t a b l e f o r a p p l i c a t i o n s r e q u i r i n g high temperature during e i t h e r o p e r a t i o n , c l e a n i n g , or sterilization and for those in which a charged membrane is advantageous. Results from two s t u d i e s i n v o l v i n g high volume recovery of multicomponent process e f f l u e n t s are presented here as illustrat i o n s o f recent a p p l i c a t i o n s o f hyperfiltration membranes in a t u b u l a r c o n f i g u r a t i o n supported by porous s t a i n l e s s steel. The first is a l a b o r a t o r y s e p a r a t i o n o f dyes from a s a l i n e dye manufacturing process e f f l u e n t and t h e second a pilot renovation of wash water from a dye range f o r reuse. The general p r o p e r t i e s o f r e p r e s e n t a t i v e dynamically-formed membranes are provided in Table I . Separation o f Dye Manufacturing

Process E f f l u e n t

In a t y p i c a l dye s y n t h e s i s t h e dye i s s a l t e d - o u t o f t h e r e a c t i o n s o l u t i o n and captured on a f i l t e r press. The dye f i l t r a t e i s normally d i l u t e d w i t h f i l t e r washings and other water sources t o as much as (100:1) (water: dye f i l t r a t e ) , t r e a t e d , and discharged from t h e p l a n t . The authentic samples of dye f i l t r a t e used i n t h i s study were h i g h l y c o l o r e d , near n e u t r a l l i q u i d s w i t h high s a l t concentrations (5 t o 20 weight percent) and a t o t a l organic carbon (TOC) c o n c e n t r a t i o n o f about 0.5 percent.

0097-6156/81/0154-0435$05.00/0 © 1981 American Chemical Society

In Synthetic Membranes: Volume II; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1981.

SYNTHETIC

436

Table I .

H F A N D U F USES

CARRE, Inc. Membrane S p e c i f i c a t i o n s

Flow Geometry Downloaded by UNIV OF CALIFORNIA SAN DIEGO on June 2, 2015 | http://pubs.acs.org Publication Date: May 27, 1981 | doi: 10.1021/bk-1981-0154.ch024

MEMBRANES:

Ultrafiltration ZOSS

Hyperfiltration ZOPA

Tubular

Tubular (3l6£)

stainless steel (3l6£)

Membrane Support

stainless steel

Membrane M a t e r i a l

zirconium

Method o f Replacement

i n place chemical solution

i n place chemical solution

Prefiltration Requirement

hO mesh screen

1+0 mesh screen

Pressure

g r e a t e r than 1000 psig

greater than 1000 psig

greater than 100°C (212°F)

greater than 100°C (212°F)

Limitation

Temperature Limitation pH Range

oxide

zirconium oxide polyacrylate

U-ll

2-13

P e r m e a b i l i t y with Test S o l u t i o n @ 100°F

0 . 1 t o O.k

0.05

8 200°F

O.k t o 1 . 2

0.2

S a l t Rejection"^

5 - 20%

80 - 90%

-

-

0.07

0.3

Test S o l u t i o n 1000 mg/l o f NaNO^ i n water Flux equals P e r m e a b i l i t y times pressure Examples: ( l ) ZOSS Membrane at 1000 p s i g at 100°F F l u x = 0 . 2 5 x 1000 = 250 g a l l o n s / d a y / f t (2) ZOPA Membrane at 1000 p s i g at 200°F Flux = 0 . 2 5 x 1000 = 250 g a l l o n s / d a y / f t ^ Flux with wastewater must be measured. c


24.

BRANDON

ET AL.

Dynamic Membranes

437

F o u r f l u i d s were s t u d i e d : f i l t r a t e s f r o m t h e m a n u f a c t u r e o f (a) "basic y e l l o w C I U 8 0 5 ^ , i n d o l e t y p e ; (b) a c i d y e l l o w C I 1 3 9 0 6 , a z o - t y p e ; ( c ) a c i d b l u e CI 6 2 0 5 5 a n t h r a q u i n o n e t y p e ; a n d (d) an e q u a l m i x t u r e o f t h e a b o v e , t e r m e d " c o m p o s i t e " . T a b l e I I i d e n t i f i e s the s t r u c t u r e s o f the product dyes. Test f l u i d s r a n g i n g i n d i l u t i o n f r o m 2 : 3 t o 1 0 0 : 1 were u s e d . A need e x i s t s t o f r a c t i o n a t e t h e s o l u t e s i n t h e dye f i l t r a t e i n t o r e t a i n e d o r g a n i c and p a s s e d i n o r g a n i c s a l t f r a c t i o n s . The passage o f simple e l e c t r o l y t e s occurs through u l t r a f i l t r a t i o n membranes a n d i o n - e x c l u s i o n h y p e r f i l t r a t i o n membranes a t a h i g h salt concentration. B o t h t y p e s o f dynamic membranes were t e s t e d . The dynamic u l t r a f i l t e r had b e e n o b s e r v e d t o r e t a i n c o l o r i n s p e n t dye s o l u t i o n s , b u t i t s c o l o r r e t e n t i o n u s i n g t h e s e d i l u t e d dye f i l t r a t e s ( 1 0 0 : 1 ) was n e g l i g i b l e and no q u a n t i t a t i v e r e s u l t s are presented. A d e s c r i p t i o n o f the experiments and p r e l i m i n a r y r e s u l t s u s i n g b a s i c y e l l o w C I U805^ a n d c o m p o s i t e f i l t r a t e s has been p u b l i s h e d . (3) R e s u l t s o b t a i n e d w i t h t h e h y p e r f i l t e r u s i n g a c i d y e l l o w C I 13906 and a c i d b l u e C I 62055 f i l t r a t e s are d e s c r i b e d here. T h e p r o p e r t i e s o f t h e dye f i l t r a t e s are p r o v i d e d i n Table I I I . The e f f e c t s o f p e r t i n e n t o p e r a t i n g p a r a m e t e r s on t h e s e p a r a t i o n p r o c e s s were m e a s u r e d . Most e x p e r i m e n t s were p e r f o r m e d a t 5 . 2 MPa (750 p s i ) . D e l i b e r a t e e x c u r s i o n s i n t e m p e r a t u r e were made t o measure t h i s e f f e c t and p r o v i d e a means o f c o m p e n s a t i n g t h e f l u x d a t a f o r t e m p e r a t u r e and r e p o r t i n g a l l c o m p a r i s o n d a t a a t U5°C. The s e p a r a t i o n o f s o l u t e s was a n t i c i p a t e d t o depend on c o n c e n t r a t i o n and pH and t h e s e e f f e c t s were d e t e r m i n e d systematically. Two e x p e r i m e n t a l p r o c e d u r e s were c a r r i e d o u t . In the f i r s t , a 1 0 0 : 1 ( w a t e r and dye f i l t r a t e ) d i l u t i o n was c o n c e n t r a t e d t o o n e - t e n t h i t s i n i t i a l v o l u m e . R e j e c t i o n b a s e d on c o l o r a b s o r b ance {hlO nm) and e l e c t r i c a l c o n d u c t i v i t y , f l u x , p r e s s u r e , t e m p e r a t u r e , a n d c r o s s f l o w r a t e were m e a s u r e d a t i n t e r v a l s during the concentration experiment. I n the second, a s l i g h t l y d i l u t e d dye f i l t r a t e ( 2 : 3 ) was u s e d and t h e h y p e r f i l t r a t i o n a t s t e a d y s t a t e was e v a l u a t e d a s i n t h e f i r s t p r o c e d u r e . The t e s t was r e p e a t e d a t d i l u t i o n s r e a c h i n g ( 1 0 0 : 1 ) , w i t h pH and t e m p e r ature excursions a t a d i l u t i o n o f 3 : 1 . The v a r i a t i o n o f f l u x w i t h t e m p e r a t u r e f o r a l l t h e f l u i d s i s shown i n F i g u r e 1 . Each t r e n d i s reasonably c o r r e l a t e d b y


5

J

= J

q

exp[-2,500 ( i - i )] o

[1]

where J Q i s t h e f l u x a t T = 3l8K ( i +5°C). T h e v a r i a t i o n o f f l u x and r e j e c t i o n s w i t h pH i s shown i n F i g u r e s 2 a n d 3 f o r t h e t w o fluids. Q


438

SYNTHETIC

Table I I .

MEMBRANES:

S t r u c t u r e s o f Product Dyes

Product Dye


H F A N D U F USES

Structure

Basic Yellow, CI hQ05k

CH

3

O^NJ-CHIN-N—^>-0C H I I C h U

C

H

C H S 0

3

3

4

3

Acid Yellow, CI 13906

S 0

2

N H

C O - N H - O

2

"

N a

f

A c i d Blue, CI 62055

0

N H



24.

BRANDON

ET AL.

Dynamic Membranes

439

Table I I I . P r o p e r t i e s o f Dye F i l t r a t e s Property

A c i d Y e l l o w , CI 13906

(mg/L)

A c i d B l u e , CI 62055

(mg/L)

CI"

116,000

12,600

TDS

217,000

111,000

COD

lU,200

Hl,900

6,l80

21,800

177,000

50,000

Alkalinity

E q u i v a l e n t NaCl

(by c o n d u c t i v i t y ) pH

9.1

9.3

Cr

0.3k

0.20

Cu

Q.kh

Ni

1.73

0.63

Zn

0.63

0.87

Hg

17.8

760.

13.8


SYNTHETIC


440

MEMBRANES:

HF

AND

UF

USES

3• 3

2- 9 103/T

Figure 1.

Effect of temperature on membraneflux:P = 5.2 MPa (750 psi)



24.

Dynamic Membranes

BRANDON E T A L .

H

1

.

1

1

441

A

I

•

A

•6 r

O 6° •

.4

° .2

•

O

I

9

conductivity

I

L

i

i

I

i

_l

I

I

I

1

L_

0 2

1 0 5 Jo (m/s)

PH

Figure 2. Rejection (r) and flux (J ) dependence on pH for the acid yellow CI 13906 filtrate: solid points at conductivity (LJ = 0.026 S/cm and open points at L = 0.06 S/cm; P = 5.2 MPa (750 psi). 0



442

SYNTHETIC

•

MEMBRANES:

HF

AND

UF

USES

•

pH

Figure 3.

Rejection (r) and flux (J ) dependence on pH for the acid blue CI 62055 filtrate: conductivity (L) = 0.042 S/cm; P = 5.2 MPa (750 psi). 0



24.

BRANDON

ET AL.

443

Dynamic Membranes

The dependence of the r e j e c t i o n s on the concentration i s o f primary i n t e r e s t . The r e j e c t i o n s and f l u x dependence on concent r a t i o n (represented by the c o n d u c t i v i t y of the feed) i s shown i n Figures h and 5 f o r the two f l u i d s . The most s i g n i f i c a n t feature i s the d i f f e r e n c e i n r e j e c t i o n based on absorbance (A) and t h a t based on c o n d u c t i v i t y ( L ) , i . e . , the d i f f e r e n c e i n r e j e c t i o n o f the c o l o r e d organic dye s a l t s and the simple s a l t s (the major c o n t r i b u t o r t o the c o n d u c t i v i t y ) . The membrane e f f e c t i v e l y concentrates the c o l o r w i t h r e j e c t i o n , r ^ , g r e a t e r than 0.9 ^or most data w h i l e passing simple s a l t s w i t h r e j e c t i o n , r ^ , l e s s than O.k at high c o n c e n t r a t i o n . This r e s u l t suggests the dependence of the s e p a r a t i o n f a c t o r , ajjj, where L a'A l

[2]

on c o n c e n t r a t i o n d i f f e r s f o r the two f l u i d s . As shown i n Figure 6, increases w i t h concentration f o r the a c i d y e l l o w CI 13906 f i l t r a t e but remains n e a r l y constant f o r the a c i d blue CI 62055 f i l t r a t e . The r e j e c t i o n o f c o l o r i s coupled w i t h t h a t of cond u c t i v i t y i n the l a t t e r f i l t r a t e but not i n the former. These r e j e c t i o n s are uncoupled i n the b a s i c y e l l o w CI kQO^h f i l t r a t e . (3_) I n c r e a s i n g i o n i c s t r e n g t h decreases the i o n - e x c l u s i o n e f f e c t i v e n e s s of charged membranes. The r e s u l t s i n d i c a t e t h a t the c o l o r e d components of the a c i d blue f i l t r a t e behave as a simple e l e c t r o l y t e , w h i l e the l a c k of a r e d u c t i o n i n the c o l o r r e j e c t i o n of the other two f l u i d s suggests the c o l o r e d species are e i t h e r l a r g e r or aggregated so t h a t t h e i r r e j e c t i o n s are independent of i o n i c s t r e n g t h . The dye f i l t r a t e s contained c o l o r e d species i n a d d i t i o n t o the product dye. This was determined by s e p a r a t i n g the c o l o r e d species by l i q u i d chromatography and comparing the e l e c t r o n i c s p e c t r a of each c o l o r e d e l u t i o n band w i t h the p u r i f i e d product dyes. Thus conclusions f o r the d i f f e r e n c e i n behavior cannot be based on the product-dye s t r u c t u r e s . I n summary, the dynamically-formed u l t r a f i l t e r d i d not separate c o l o r e d compounds from the s a l t . The dynamicallyformed h y p e r f i l t e r e f f e c t i v e l y r e t a i n e d the c o l o r e d compounds w h i l e p r o v i d i n g low r e j e c t i o n of the s a l t . Because the s a l t r e j e c t i o n was low i n the concentrated s o l u t i o n s r e s u l t i n g i n low osmotic pressure d i f f e r e n c e s , the f i l t r a t i o n of concentrated s o l u t i o n s w i t h high i o n i c strengths could be accomplished at the r e l a t i v e l y low o p e r a t i n g pressure o f 5-2 MPa (750 p s i ) . Renovation of Dye Range Wash Water f o r Reuse A p r o j e c t i s i n progress t o demonstrate the c l o s e d - c y c l e operation of a production dye range. The cooperative agreement w i t h LaFrance I n d u s t r i e s i n v o l v e s the Environmental P r o t e c t i o n


444

SYNTHETIC MEMBRANES:

A

>

1

A

1

k

HF

AND U F

USES

A


a b s o r b a n c e

%>

o

O O 0 O 1

1

1

conductivity

• •

•

•

•

•

i

0 0

.02

l .04 C o n d u c t i v i t y

Figure 4.

i .08

1

.0 6 (

.10

S/cm)

Rejection (v) and flux (J ) vs. conductivity for the acid yellow CI 13906 filtrate: P = 5.2 MPa (750 psi). 0


BRANDON

445

Dynamic Membranes

ET AL.

1.0

A .8 .6 r

O O

.4 .2

con ducti vity

I

l_


0 2

10° J

0

(m/s)

O

• o

0

.02

.04

.06

-08

(s/cm)

Conductivity

Figure 5. Rejection (r) and flux (J ) vs. conductivity for the acid blue CI 62055 filtrate:filledsymbols represent the concentration procedure; open symbols the dilution procedure; P = 5.2 MPa (750 psi). 0

30

I O

y e l l o w

A

blue

o

-

O

o

* \

A A i

D

Figure 6.

o

O

10

.1

I

.2

I

.3

L

Dependence of the separation factor « feed

A

>4

on the conductivity (L) of the


In Synthetic Membranes: Volume II; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1981. FLUX, GAL/FT

/DAY

DIRECT ACRYLIC BLEACH


DIRECT ACRYLIC DISPERSED DIRECT ACRYLIC DISPERSED DIRECT ACRYLIC ACRYLIC ACRYLIC DIRECT AUTOMOTIVE ACRYLIC DIRECT ACRYLIC DIRECT DIRECT DIRECT AUTOMOTIVE ACRYLIC DIRECT ACRYLIC BLEACH DCRECT DIRECT DIRECT DIRECT ACRYLIC DIRECT ACRYLIC DISPERSED DIRECT REACTTVE DIRECT

S3Sn 3fl QNV 3H :S3NVHaiA[3P\[ 3U3H1NAS

9yJ7


T Y P F

Recent Applications of Dynamic Membranes - American Chemical

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