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Live seawater experience in Japan with hollow fiber permeators
Desalinat,on. 19 (1976) 439-446 0 Ekv~er Scientific Publishing Company, Amsterd.un - Printed in The Netherlands
I,IVE SEAWATER
EXPERIENCE
IN JAP,AN WITH
BOLLOW
FIBER
PERXBATOBS
Y. Murayama,
T. Kasamatsu and J. G. Gaydos WATER REUSE CENTER, M.I.T.X. JAPAN
Abstract 1n VICW of the incrranlng
neccssrty to save energy. '_!:cdtisalinatron of the reverse osmose (2.0.; method, 1s becomznq veq Important. With escalating importance of R-0.. as a desalinatron process, the "Water Fe-use Promction Center" In Japan LS carrying out devcloymcnt work on the actual applrcatlon of R.O. to the dcsallnation of sea water. Tiirs work is sponsored by the Industrial Water Section of the >Unistry of Intcrnatronal Trade and Industry rp. Japan. sea
water
by
This rcporc will B-10 module, for at the Chioasajcr Japan.
show that sea water Laboratoc
satisfactory results were obtained with the desalination under actual test conditions of cnc "Water Re-use Promotion Center" in
The tl%perimental facility USES DuPont 'icilow-Frber type B-10 Pcrmascp Perllrators, which nave been developed for sing1 e pass desalinatron of sea water. Sssakura Engrnecr~ng Conpsn~* Ltd., designed and fabrrcatcd the pre-treatment and R-0. facility for the test by the "Water Re-USC Promotion Center." 1.
Experirwntal
Facrllty
l-1 Water
Xnta!!e
The water 7 meters.
intake is locatad 700 meters off-shore The saa water :s :>lmpcd rn.
Chlorine
rnto
a depth
of
by the
clectrolysrs of sea water IS in3ected intal'-c sectron so that the rcsldual is maintained_
the top of the water
chlorine L-2
obtained
with
Sea
content Water
Pre-treaL-cnr
The pre-treatment facility 1s used to remove collordal foulants from the sea *wa'Ier and to obtazn treated feed waccr havrng a Fouling Index (F.1.) less than 3. rnto an actrvated carbon tower, First, sea water is introduced uhc?re the residual chlorine and foreign matter of relazively large size is removed.
Then,
coagulant PAC (polyalumrnum chlorine) is added to the In order to water at the outlet from the activated carbon towc:r_ llromote the coagulating ability of PAC, BC1 is added and the pH By reducrnq the pH value, stable floe 1s adjusted to 6.0 - 6.5. 1s forr*led with aluminum hydroxide and the colloidal foulants are trapped in the floe.
139
t-l
Sea
51acer
Tre-treatment
2-2
Sea
-X~ter
R-O_
Serges re3ect is adopted 1s this experiment 1stconsrderatrcn of The series reject, means that the stasrLrzrsq actuai o~eratim. concentrated sea water after desalinatlm ur:h a full srze wduie is passed agalr. *a a second half size module Whose mernhrane area 1s half of tn.e foIL size m&uIeL. fn consideratxor; xrfsce and also
size m&ale mzt is ?mId to dmut
of concentratron poLarFtation near the immbrane. scale degosrtLon, the recover! of tke blf be kept low. In this experrmental faclirty, it SaLf of the f.alL size mxIi;Le. of
0-t arrasgcment is to increase the The purpose of tms series rej_+ flow rate per module, tnus rncreasing the fLcw velocity rnslde the smdufe and reducing the contaswmtxon and scale deimsrtron 3% tke nezIhrane_ T5.e aim 15 to &cn~e*lr high yield and acquire a Larger axmmt Gf product ovet d Long period. ky ustng thzs operating mr>ne2-2-2 hdjustawznt of the Pecovery Patio Et,dcst~:nq of the aet;laI plant, the capacity of rhe module is selccred in consideration of deterloratron of :he new swduLe capacity, caused b-f compaction of the membrane after Iony continuous operatlorr. Therefore, when a new module is used and operation is at the design pressure of 56 kg/cmZG. the product roll exceed the desrgn value. it is in this regard desired that the lnitzal pressure is reduced to
a
value
at
which
the
design
product
water
rate
may
he
maintained.
a result of this OperationaL method. compaction of the membrane is reduced, and further deterioration of the mdule performance is reduced. Accordingly, the initial pressure of this experiment is set at 51.1 kg/cm2G and the recover at 28.42.
As
At the pornt III tlmc when the recovery ratlo E. reduced eo below .?8i during contrnuous opcratlon because of membrane compaction. tnc p:essurc 1s adlusted up to the max. 56 kg/cn2G, so that the rcc~.wq rate? of 20 .- 3O‘i ~a obtained. 3.
Cxperlmentai 3-1 Sea
Results
Water
Pre-treatment
Device
%* of P;\C to normal After a-fdtn.3 several PP.. men= was na3c. an F-1. 3f less than 3 was Eocdwater.
sea water and #i adpstattarned i:~ the trwt4
Even wnen sea water condrtions detcrlorated, an F-1. of Less than could be obtained by incrcas;lr.g the amount of PAC addrtron oc by alss addrng PAC at the inlet of the fine filter. Sea
3-z
Water
R-0.
A 3,300 hour conc~nuous operation test LS now underway. 3,000 hours shall be reached 2.500 hours have passed.
So far, on August
the results are satisfactory and T.O prod\rct flux At present. Product water quality from compaction has been experienced, wrtn a value of less than 600 micro n&os/cm. 3-f -1 Product
Fig.
3
(Curve
1)
shows
the tlmc.
change
of product
flux
23.
decline is good
Flux
withelapsed
3
in accordance
For tne first 451 hours after the start of operation. the module inlet pressure was set at 51.7 k /cm2G, from 453 s hours to 1.000 hours, it wns 52.2 kg/cm-G. after 1,000 hours, operation was at 52-8 kg/c&G_ In spite of using a new module. the product flux reduction by compaction hardly occurred, and the product fiuv was 280 - 300 l/h (at ?SmC) during operation.
HOLLOh' FIBER 3-2-2
PERNEATORS
Pressure
loss
LX JAPAN (Ap)
Inside
443 the Nodule.
P~cssurc Loss (ApI remazncd essentially constant. In the full size module. .ip = 1.0 Kg/cm2. In the case of the half size module, &I = 0.8 kg/cm2. 3-2-3 Fig.
3-2-4
Rocovcry 3 (CUWF iI shows the recovery variation with respect to -elapsed time. Hig.;‘land stable recovery of 28 - 305 r,as maintained continuously during operation. Water
Temperature
For the fxrst 660 hours, the rc)ect temperature was 22 - ?S°C. Since then, sea water temperature has Increased. The re]ecC tcapcraturc was 28 - 33OC at the end of 2500 hours operation. 3-2-5 Fig.
product
Water
Quality
3 (Cur?.? 3) shows the rclatlo? bctwecn time and the elcctrrc conductlvrty (E.2.) of the product water. As S~WUII therern. the product water qualrtv 1s good and stabilrzed.
Table
I. Indicates the analysrs of the product water at the Even in terms of the 1,OOOth hour and 2,300th hour. mono-valent Ions of Naf, CL- and K+, the salt rejection was more than 99.7%.
444
Y. MURAYAHA.
4.
of Membrane
Analysis
Physical
T. KASAMATSU
AND
3-C.
GAYWS
Property
In order to assess the deterioration of the UM3Ubxane PerfOrmancc and the service life of the membrane, it is important to define the membrane physical properties and coefficients. which the R-IO module Possesses xn a quantitative way. other To obtain these values, the pure water and artificial operation with sea water. The data analysis was the guidance of Prof. 4-1
Pressure
A =
L
Ao
exp
were asxde
carried out with from the continuous
executed with a coclputer program under H. Ohyal) of Yokohama National University.
Dependence
The relation between Equatio:? (1)
experiments sea water.
of Pure
value
(
-
d
Water
(A) and
3
---
Permeability
pressure
can
be
and
6
Constant
(A)
expressed
by
(1)
lc-Fig.
4 shows
the
log plot
of
A
"
L 11 1 1:
‘; ,! --Q-----Q-~
Since the dependence range4-2
I I’
value of a is 0.0014 ot so. the pressure can be said to be negligible Vxthin this
Pressure
Dependence
of
the
The relation between DAM/K& and Equation (21 and Fig. 5 indicates
DMVKA
= :DWKACI)
exp
Salt
Transport
Pressure
Parameter
pressure can be expressed the log plot of DAM&A (-BP)
---
(2)
mK>
by and F.
HOLLOW
FIBER
PERMEATORS
IN JAPAN
445
The value of DAM/K& is 1.8 - 2.4 x lo-' (cm/set) significant improvement is achieved in comparison module for brackish water. 4-3
Mass
Transfer
Coefficient
Through
Membrane
and a with the
(K) vs
Feed
Rate
As shown in Fig. 6. the value of K does not show any remarkable change even if the feed rate is changed_ K value is 7 x 10-5 (cm,'sccl at Feed = 1.000 - 1.700 l/h_ This suggests that the mfluence of the concentration polarization is small. 4-4 Valueof
-c x -,
(ml in Continuous
,
Plant Fig.
38
elapsed
Sea
w
time,
Water
*
I
m
Y-
-
-+SW
*
h
7 shows the variation of (A) value with elapsed time This (A) value is during this continuous operdtionobtained by using the product water at the module inlet pressure of 56 kg/cm2G during the continuous operation.
If equation (3) is applicable for the value of (A) then obtained from (ml = O.Oi2, which Indicates that membrane compaction hardly takes place. log At = log Ao - m log
t ----
(3)
value
is
446
Y. MURAYAMA. T. KASAI'IATSU AND J.G.
GAYWS
5. Conclusion Throughout the long continuous operation. the economical 28 - 30% recovery could be maintained. The product quality showed electric conductivity vaLues of below )Ucm (as TM 400 ppml. No product flux decline was recorded due to membrane compaction. Since the rated pressure of the module is 56 kq/cm*C. there is still some allowance m pressure, and it is possible to maintain the mdule performce over a longer period. consideratFon was given to the operational In this experiment, conditions of the one pass sea water desalination plant for The results obtalned confirm that good pcrforcommercial use. mance can be achieved by using Permasep Hollow-Fiber B-10 under practical conditions. R.O. Modules
Reference 1) 1975 "Report on the development of Energy-savxng P98-110. Sea Xater Desalination Technolwy"
Type
I,IVE SEAWATER
EXPERIENCE
IN JAP,AN WITH
BOLLOW
FIBER
PERXBATOBS
Y. Murayama,
T. Kasamatsu and J. G. Gaydos WATER REUSE CENTER, M.I.T.X. JAPAN
Abstract 1n VICW of the incrranlng
neccssrty to save energy. '_!:cdtisalinatron of the reverse osmose (2.0.; method, 1s becomznq veq Important. With escalating importance of R-0.. as a desalinatron process, the "Water Fe-use Promction Center" In Japan LS carrying out devcloymcnt work on the actual applrcatlon of R.O. to the dcsallnation of sea water. Tiirs work is sponsored by the Industrial Water Section of the >Unistry of Intcrnatronal Trade and Industry rp. Japan. sea
water
by
This rcporc will B-10 module, for at the Chioasajcr Japan.
show that sea water Laboratoc
satisfactory results were obtained with the desalination under actual test conditions of cnc "Water Re-use Promotion Center" in
The tl%perimental facility USES DuPont 'icilow-Frber type B-10 Pcrmascp Perllrators, which nave been developed for sing1 e pass desalinatron of sea water. Sssakura Engrnecr~ng Conpsn~* Ltd., designed and fabrrcatcd the pre-treatment and R-0. facility for the test by the "Water Re-USC Promotion Center." 1.
Experirwntal
Facrllty
l-1 Water
Xnta!!e
The water 7 meters.
intake is locatad 700 meters off-shore The saa water :s :>lmpcd rn.
Chlorine
rnto
a depth
of
by the
clectrolysrs of sea water IS in3ected intal'-c sectron so that the rcsldual is maintained_
the top of the water
chlorine L-2
obtained
with
Sea
content Water
Pre-treaL-cnr
The pre-treatment facility 1s used to remove collordal foulants from the sea *wa'Ier and to obtazn treated feed waccr havrng a Fouling Index (F.1.) less than 3. rnto an actrvated carbon tower, First, sea water is introduced uhc?re the residual chlorine and foreign matter of relazively large size is removed.
Then,
coagulant PAC (polyalumrnum chlorine) is added to the In order to water at the outlet from the activated carbon towc:r_ llromote the coagulating ability of PAC, BC1 is added and the pH By reducrnq the pH value, stable floe 1s adjusted to 6.0 - 6.5. 1s forr*led with aluminum hydroxide and the colloidal foulants are trapped in the floe.
139
t-l
Sea
51acer
Tre-treatment
2-2
Sea
-X~ter
R-O_
Serges re3ect is adopted 1s this experiment 1stconsrderatrcn of The series reject, means that the stasrLrzrsq actuai o~eratim. concentrated sea water after desalinatlm ur:h a full srze wduie is passed agalr. *a a second half size module Whose mernhrane area 1s half of tn.e foIL size m&uIeL. fn consideratxor; xrfsce and also
size m&ale mzt is ?mId to dmut
of concentratron poLarFtation near the immbrane. scale degosrtLon, the recover! of tke blf be kept low. In this experrmental faclirty, it SaLf of the f.alL size mxIi;Le. of
0-t arrasgcment is to increase the The purpose of tms series rej_+ flow rate per module, tnus rncreasing the fLcw velocity rnslde the smdufe and reducing the contaswmtxon and scale deimsrtron 3% tke nezIhrane_ T5.e aim 15 to &cn~e*lr high yield and acquire a Larger axmmt Gf product ovet d Long period. ky ustng thzs operating mr>ne2-2-2 hdjustawznt of the Pecovery Patio Et,dcst~:nq of the aet;laI plant, the capacity of rhe module is selccred in consideration of deterloratron of :he new swduLe capacity, caused b-f compaction of the membrane after Iony continuous operatlorr. Therefore, when a new module is used and operation is at the design pressure of 56 kg/cmZG. the product roll exceed the desrgn value. it is in this regard desired that the lnitzal pressure is reduced to
a
value
at
which
the
design
product
water
rate
may
he
maintained.
a result of this OperationaL method. compaction of the membrane is reduced, and further deterioration of the mdule performance is reduced. Accordingly, the initial pressure of this experiment is set at 51.1 kg/cm2G and the recover at 28.42.
As
At the pornt III tlmc when the recovery ratlo E. reduced eo below .?8i during contrnuous opcratlon because of membrane compaction. tnc p:essurc 1s adlusted up to the max. 56 kg/cn2G, so that the rcc~.wq rate? of 20 .- 3O‘i ~a obtained. 3.
Cxperlmentai 3-1 Sea
Results
Water
Pre-treatment
Device
%* of P;\C to normal After a-fdtn.3 several PP.. men= was na3c. an F-1. 3f less than 3 was Eocdwater.
sea water and #i adpstattarned i:~ the trwt4
Even wnen sea water condrtions detcrlorated, an F-1. of Less than could be obtained by incrcas;lr.g the amount of PAC addrtron oc by alss addrng PAC at the inlet of the fine filter. Sea
3-z
Water
R-0.
A 3,300 hour conc~nuous operation test LS now underway. 3,000 hours shall be reached 2.500 hours have passed.
So far, on August
the results are satisfactory and T.O prod\rct flux At present. Product water quality from compaction has been experienced, wrtn a value of less than 600 micro n&os/cm. 3-f -1 Product
Fig.
3
(Curve
1)
shows
the tlmc.
change
of product
flux
23.
decline is good
Flux
withelapsed
3
in accordance
For tne first 451 hours after the start of operation. the module inlet pressure was set at 51.7 k /cm2G, from 453 s hours to 1.000 hours, it wns 52.2 kg/cm-G. after 1,000 hours, operation was at 52-8 kg/c&G_ In spite of using a new module. the product flux reduction by compaction hardly occurred, and the product fiuv was 280 - 300 l/h (at ?SmC) during operation.
HOLLOh' FIBER 3-2-2
PERNEATORS
Pressure
loss
LX JAPAN (Ap)
Inside
443 the Nodule.
P~cssurc Loss (ApI remazncd essentially constant. In the full size module. .ip = 1.0 Kg/cm2. In the case of the half size module, &I = 0.8 kg/cm2. 3-2-3 Fig.
3-2-4
Rocovcry 3 (CUWF iI shows the recovery variation with respect to -elapsed time. Hig.;‘land stable recovery of 28 - 305 r,as maintained continuously during operation. Water
Temperature
For the fxrst 660 hours, the rc)ect temperature was 22 - ?S°C. Since then, sea water temperature has Increased. The re]ecC tcapcraturc was 28 - 33OC at the end of 2500 hours operation. 3-2-5 Fig.
product
Water
Quality
3 (Cur?.? 3) shows the rclatlo? bctwecn time and the elcctrrc conductlvrty (E.2.) of the product water. As S~WUII therern. the product water qualrtv 1s good and stabilrzed.
Table
I. Indicates the analysrs of the product water at the Even in terms of the 1,OOOth hour and 2,300th hour. mono-valent Ions of Naf, CL- and K+, the salt rejection was more than 99.7%.
444
Y. MURAYAHA.
4.
of Membrane
Analysis
Physical
T. KASAMATSU
AND
3-C.
GAYWS
Property
In order to assess the deterioration of the UM3Ubxane PerfOrmancc and the service life of the membrane, it is important to define the membrane physical properties and coefficients. which the R-IO module Possesses xn a quantitative way. other To obtain these values, the pure water and artificial operation with sea water. The data analysis was the guidance of Prof. 4-1
Pressure
A =
L
Ao
exp
were asxde
carried out with from the continuous
executed with a coclputer program under H. Ohyal) of Yokohama National University.
Dependence
The relation between Equatio:? (1)
experiments sea water.
of Pure
value
(
-
d
Water
(A) and
3
---
Permeability
pressure
can
be
and
6
Constant
(A)
expressed
by
(1)
lc-Fig.
4 shows
the
log plot
of
A
"
L 11 1 1:
‘; ,! --Q-----Q-~
Since the dependence range4-2
I I’
value of a is 0.0014 ot so. the pressure can be said to be negligible Vxthin this
Pressure
Dependence
of
the
The relation between DAM/K& and Equation (21 and Fig. 5 indicates
DMVKA
= :DWKACI)
exp
Salt
Transport
Pressure
Parameter
pressure can be expressed the log plot of DAM&A (-BP)
---
(2)
mK>
by and F.
HOLLOW
FIBER
PERMEATORS
IN JAPAN
445
The value of DAM/K& is 1.8 - 2.4 x lo-' (cm/set) significant improvement is achieved in comparison module for brackish water. 4-3
Mass
Transfer
Coefficient
Through
Membrane
and a with the
(K) vs
Feed
Rate
As shown in Fig. 6. the value of K does not show any remarkable change even if the feed rate is changed_ K value is 7 x 10-5 (cm,'sccl at Feed = 1.000 - 1.700 l/h_ This suggests that the mfluence of the concentration polarization is small. 4-4 Valueof
-c x -,
(ml in Continuous
,
Plant Fig.
38
elapsed
Sea
w
time,
Water
*
I
m
Y-
-
-+SW
*
h
7 shows the variation of (A) value with elapsed time This (A) value is during this continuous operdtionobtained by using the product water at the module inlet pressure of 56 kg/cm2G during the continuous operation.
If equation (3) is applicable for the value of (A) then obtained from (ml = O.Oi2, which Indicates that membrane compaction hardly takes place. log At = log Ao - m log
t ----
(3)
value
is
446
Y. MURAYAMA. T. KASAI'IATSU AND J.G.
GAYWS
5. Conclusion Throughout the long continuous operation. the economical 28 - 30% recovery could be maintained. The product quality showed electric conductivity vaLues of below )Ucm (as TM 400 ppml. No product flux decline was recorded due to membrane compaction. Since the rated pressure of the module is 56 kq/cm*C. there is still some allowance m pressure, and it is possible to maintain the mdule performce over a longer period. consideratFon was given to the operational In this experiment, conditions of the one pass sea water desalination plant for The results obtalned confirm that good pcrforcommercial use. mance can be achieved by using Permasep Hollow-Fiber B-10 under practical conditions. R.O. Modules
Reference 1) 1975 "Report on the development of Energy-savxng P98-110. Sea Xater Desalination Technolwy"
Type