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Rejection of metallic cations
ISSN 0958-2118
1994/6
An International Newsletter
Number 50
Membrane Technology Aqueous wash clean-up brings savings A s e l f - i m p o s e d b a n on c h l o r i n a t e d solvents h a s led to e n v i r o n m e n t a l i m p r o v e m e n t s a n d large cost savings for w a s t e d i s p o s a l a t R a n k Xerox's M i t c h e l d e a n m a n u f a c t u r i n g p l a n t n e a r Gloucester, UK. The p l a n t is a d o p t i n g n e w mtcroflltration t e c h n o l o g y from NWW A c u m e m , u n d e r a t u r n k e y c o n t r a c t , for its newly i n s t a l l e d a q u e o u s w a s h system. E x t e n d e d t r i a l s at the p l a n t have s h o w n t h a t the filtration t e c h n i q u e will s e p a r a t e d e t e r g e n t c l e a n e r a n d w a t e r for recycling while c o n c e n t r a t i n g t h e s u s p e n d e d solids a n d off c o n t a m i n a t i o n for d i s p o s a l . The volume of w a s t e h a s therefore p l u m m e t e d , giving u p to a 95% saving in d i s p o s a l costs. Detergent c o s t s h a v e also b e e n r e d u c e d b y u p to 95%. In a d d i t i o n to the m i c r o f i l t r a t i o n p r o c e s s , A c u m e m is i n s t a l l i n g a reverse o s m o s i s p l a n t to give a final p o l i s h to the a q u e o u s effluent prior to recycling. The trials demonstrated that a constant cleaning quality c a n be set a n d m a i n t a i n e d u s i n g t h e c o m b i n a t i o n of microfiltration a n d reverse o s m o s i s , offering a very high level of q u a l i t y control, s a y s t h e c o m p a n y .
Further Informatlon from: Joy Lawless, N W W A c u m e m Ltd, The Heath, Runcorn, Cheshire WA7 4QD, UK. Tel: 0928 515959. Fax: 0 9 2 8 517891. Or: Alan Dahlqvlst, N W W A c u m e m Inc, 2724 Loker A v e West, Carlsbad, CA 92008, USA. Tel: +1 619 929 7500. Fax: +1 619 929 7510.
R e j e c t i o n of metallic cations ELSEVIER ADVANCED TECtlNOLOGY
In a p a p e r in the Journal o f Membrane Science, (91, p p 87-95), r e s u l t s a r e p r e s e n t e d for t h e rejection of metallic c a t i o n s b y m e a n s of a g a m m a a l u m i n a n a n o f l l t r a t i o n m e m b r a n e , p r e p a r e d b y a sol-gel process. The e x p e r i m e n t s were i n t e n d e d to s h o w if it m a y be p o s s i b l e to remove s m a l l meta/llc c a t i o n s b y m e a n s
@1994 Elsevier 8¢~ienoe Ltd., E n g l a n d . / 9 4 / $ 7 . 0 0 per i t e m No part of this publication may be reproduced, stored in a retrieval system, or transmitted by. any form or by anymeans, electronic, mechanical, photocop~ng, recording or otherwise, without the prior permiss~on of me pubhsners. (Readers in the U.S.A. w please see special regulations listed on back coverj
News and Views of nanoflltration m e m b r a n e s a n d molecular ligands. Complexation of metallic cations with molecular ligands is advantageous, as the relative a m o u n t of each species in solution c a n be easily obtained, and also the molecular ligands keep the same conformation w h e n the composition of the solution is modified. This m e a n s that pH a d j u s t m e n t of the feed will not modify the viscosity of the solution. The m e m b r a n e used h a d a pore size diameter of 1 n m a n d a cutoff of 400. Experiments showed that rejections a n d fluxes depend on the size a n d charge of the complex. For positively charged complexes, the flux of the permeate was almost independent of the pH of the solution, whereas for negatively charged ones, the flux increased with increasing pH. In order to obtain a rejection of the metal higher t h a n 95%, the complexing agent m u s t be c h o s e n taking into consideration its molecular weight a n d the stoichiometry of the complex so that the molecular weight of the complex is higher t h a n the cutoff of the membrane. The a u t h o r s concluded that for the treatment of wastewater in an industrial process, it is still necessary to improve the flux of this membrane. Further Informatlon from: J Sarrazln, Laboratolre de Physlcochlmle d e s Materlaux, URA 1312 CNRS, 8 Rue de l'Ecole Normale, F-34053 Montpelller Cedex 1, France.
Membrane performance tested to high temperatures A new high temperature, s k i d - m o u n t e d OSMO process evaluation system (PES) from Osmonics tests reverse osmosis (RO), ultraflltration (UF) a n d nanofiltration (NF) applications at t e m p e r a t u r e s u p to 200°F (93°C). The OSMO-8OBXXSS-HT unit features 316 stainless steel c o n s t r u c t i o n a n d a n integrally-mounted heat exchanger. The unit holds u p to eight 4-inch diameter OSMO RO, NF or UF sepralators (membrane elements) to evaluate feed rates from 2 to 20 gpm (7.6 to 75.7 Lpm) at p r e s s u r e s from 50 to 800 psig (3.4 to 55.2 bar). All systems feature a clean-in-place (CIP) system that includes a separate p u m p to transfer the test solution to the OSMO PES unit. The unit h a s microprocessor-based controls, which are adaptable to a variety of chemical processes. The NEMA- 12 electrical cabinet h o u s e s six safety alarms to protect the m e m b r a n e system including the p u m p a n d membranes.
2
Osmonlcs n e w high temperature process evaluation system.
Applications include inorganic/organic separations, desalting (purifying) fine chemicals, separating a n d concentrating foods, concentrating waste materials before disposal, a n d more. Further Informatlon from: Osmonlcs Inc, 5951 Clearwater Drlve, Mlnnetonka, MN 55343-8990, USA. Tel: +1 612 933 2277. Fax: +1 612 933 0141.
Elga wins Portugal
in
Elga Ltd h a s won a £155 000 export order from Texas I n s t r u m e n t s for a n u p g r a d e d system to supply high purity water for use in the m a n u f a c t u r e of integrated circuits at its plant in Oporto, Portugal. Under the contract, Elga h a s supplied three fully automatic Intercept RO 4 'S' four module reverse osmosis units, each capable of producing 900 L / h of permeate from a 1280 L / h feed. Associated equipment also supplied by Elga includes three UV sterilization units, pre- a n d post-treatment facilities a n d deaeration equipment. Further Informatlon from: Elga Ltd, High Street, Lane End, High Wycombe, B u c k s HP14 3JH, UK. Tel: 0494 881393. Fax: 0494 881007.
M e m b r a n e T e c h n o l o g y No. 5 0
1994/6
An International Newsletter
Number 50
Membrane Technology Aqueous wash clean-up brings savings A s e l f - i m p o s e d b a n on c h l o r i n a t e d solvents h a s led to e n v i r o n m e n t a l i m p r o v e m e n t s a n d large cost savings for w a s t e d i s p o s a l a t R a n k Xerox's M i t c h e l d e a n m a n u f a c t u r i n g p l a n t n e a r Gloucester, UK. The p l a n t is a d o p t i n g n e w mtcroflltration t e c h n o l o g y from NWW A c u m e m , u n d e r a t u r n k e y c o n t r a c t , for its newly i n s t a l l e d a q u e o u s w a s h system. E x t e n d e d t r i a l s at the p l a n t have s h o w n t h a t the filtration t e c h n i q u e will s e p a r a t e d e t e r g e n t c l e a n e r a n d w a t e r for recycling while c o n c e n t r a t i n g t h e s u s p e n d e d solids a n d off c o n t a m i n a t i o n for d i s p o s a l . The volume of w a s t e h a s therefore p l u m m e t e d , giving u p to a 95% saving in d i s p o s a l costs. Detergent c o s t s h a v e also b e e n r e d u c e d b y u p to 95%. In a d d i t i o n to the m i c r o f i l t r a t i o n p r o c e s s , A c u m e m is i n s t a l l i n g a reverse o s m o s i s p l a n t to give a final p o l i s h to the a q u e o u s effluent prior to recycling. The trials demonstrated that a constant cleaning quality c a n be set a n d m a i n t a i n e d u s i n g t h e c o m b i n a t i o n of microfiltration a n d reverse o s m o s i s , offering a very high level of q u a l i t y control, s a y s t h e c o m p a n y .
Further Informatlon from: Joy Lawless, N W W A c u m e m Ltd, The Heath, Runcorn, Cheshire WA7 4QD, UK. Tel: 0928 515959. Fax: 0 9 2 8 517891. Or: Alan Dahlqvlst, N W W A c u m e m Inc, 2724 Loker A v e West, Carlsbad, CA 92008, USA. Tel: +1 619 929 7500. Fax: +1 619 929 7510.
R e j e c t i o n of metallic cations ELSEVIER ADVANCED TECtlNOLOGY
In a p a p e r in the Journal o f Membrane Science, (91, p p 87-95), r e s u l t s a r e p r e s e n t e d for t h e rejection of metallic c a t i o n s b y m e a n s of a g a m m a a l u m i n a n a n o f l l t r a t i o n m e m b r a n e , p r e p a r e d b y a sol-gel process. The e x p e r i m e n t s were i n t e n d e d to s h o w if it m a y be p o s s i b l e to remove s m a l l meta/llc c a t i o n s b y m e a n s
@1994 Elsevier 8¢~ienoe Ltd., E n g l a n d . / 9 4 / $ 7 . 0 0 per i t e m No part of this publication may be reproduced, stored in a retrieval system, or transmitted by. any form or by anymeans, electronic, mechanical, photocop~ng, recording or otherwise, without the prior permiss~on of me pubhsners. (Readers in the U.S.A. w please see special regulations listed on back coverj
News and Views of nanoflltration m e m b r a n e s a n d molecular ligands. Complexation of metallic cations with molecular ligands is advantageous, as the relative a m o u n t of each species in solution c a n be easily obtained, and also the molecular ligands keep the same conformation w h e n the composition of the solution is modified. This m e a n s that pH a d j u s t m e n t of the feed will not modify the viscosity of the solution. The m e m b r a n e used h a d a pore size diameter of 1 n m a n d a cutoff of 400. Experiments showed that rejections a n d fluxes depend on the size a n d charge of the complex. For positively charged complexes, the flux of the permeate was almost independent of the pH of the solution, whereas for negatively charged ones, the flux increased with increasing pH. In order to obtain a rejection of the metal higher t h a n 95%, the complexing agent m u s t be c h o s e n taking into consideration its molecular weight a n d the stoichiometry of the complex so that the molecular weight of the complex is higher t h a n the cutoff of the membrane. The a u t h o r s concluded that for the treatment of wastewater in an industrial process, it is still necessary to improve the flux of this membrane. Further Informatlon from: J Sarrazln, Laboratolre de Physlcochlmle d e s Materlaux, URA 1312 CNRS, 8 Rue de l'Ecole Normale, F-34053 Montpelller Cedex 1, France.
Membrane performance tested to high temperatures A new high temperature, s k i d - m o u n t e d OSMO process evaluation system (PES) from Osmonics tests reverse osmosis (RO), ultraflltration (UF) a n d nanofiltration (NF) applications at t e m p e r a t u r e s u p to 200°F (93°C). The OSMO-8OBXXSS-HT unit features 316 stainless steel c o n s t r u c t i o n a n d a n integrally-mounted heat exchanger. The unit holds u p to eight 4-inch diameter OSMO RO, NF or UF sepralators (membrane elements) to evaluate feed rates from 2 to 20 gpm (7.6 to 75.7 Lpm) at p r e s s u r e s from 50 to 800 psig (3.4 to 55.2 bar). All systems feature a clean-in-place (CIP) system that includes a separate p u m p to transfer the test solution to the OSMO PES unit. The unit h a s microprocessor-based controls, which are adaptable to a variety of chemical processes. The NEMA- 12 electrical cabinet h o u s e s six safety alarms to protect the m e m b r a n e system including the p u m p a n d membranes.
2
Osmonlcs n e w high temperature process evaluation system.
Applications include inorganic/organic separations, desalting (purifying) fine chemicals, separating a n d concentrating foods, concentrating waste materials before disposal, a n d more. Further Informatlon from: Osmonlcs Inc, 5951 Clearwater Drlve, Mlnnetonka, MN 55343-8990, USA. Tel: +1 612 933 2277. Fax: +1 612 933 0141.
Elga wins Portugal
in
Elga Ltd h a s won a £155 000 export order from Texas I n s t r u m e n t s for a n u p g r a d e d system to supply high purity water for use in the m a n u f a c t u r e of integrated circuits at its plant in Oporto, Portugal. Under the contract, Elga h a s supplied three fully automatic Intercept RO 4 'S' four module reverse osmosis units, each capable of producing 900 L / h of permeate from a 1280 L / h feed. Associated equipment also supplied by Elga includes three UV sterilization units, pre- a n d post-treatment facilities a n d deaeration equipment. Further Informatlon from: Elga Ltd, High Street, Lane End, High Wycombe, B u c k s HP14 3JH, UK. Tel: 0494 881393. Fax: 0494 881007.
M e m b r a n e T e c h n o l o g y No. 5 0