- Email: [email protected]
High recovery concentrator
News and Views h a s a resistivity of 1 m e g a o h m p e r cm. R e g e n e r a t i o n of t h e c a t i o n a n d a n i o n c o l u m n s is s i m u l t a n e o u s , p r o d u c i n g effluents t h a t a r e largely s e l f - n e u t r a l i s i n g t h u s m i n i m i s i n g t h e e n v i r o n m e n t a l impact. After d e i o n i s a t i o n , t h e w a t e r is fed into two holding tanks and pumped constantly around a ring-main w h i c h s u p p l i e s p r o c e s s w a t e r to m i x i n g t a n k s in the p r o d u c t i o n a r e a via t a k e - o f f points. The t a n k s , mixing v e s s e l s a n d d i s t r i b u t i o n p i p e w o r k a r e all c o n s t r u c t e d from s t a i n l e s s steel. Microfilters a n d a n ultraviolet l a m p a r e i n c o r p o r a t e d into the d i s t r i b u t i o n loop to e n s u r e t h a t t h e b a c t e r i a l c o u n t is k e p t below 10 colony-formlng u n i t s p e r mL (CFU/mL). The l a b o r a t o r y w a t e r p u r i f i c a t i o n s y s t e m f e a t u r e s reverse osmosis, d e i o n i s a t i o n , microflltration a n d UV i r r a d i a t i o n . As in t h e c a s e of t h e p r o c e s s system, the purified w a t e r is c o n t i n u a l l y r e c i r c u l a t e d a r o u n d a d i s t r i b u t i o n loop w h i c h feeds take-off p o i n t s in the laboratories.
Further Informatlon from: Elga Ltd, High Street, Lane End, High Wycombe, Buckinghamshire, HP14 3JH, UK. Tel: +44 (0)494 881393. Fax: +44 (0)494 881007.
Call for p a p e r s The 7th I n t e r n a t i o n a l S y m p o s i u m on S y n t h e t i c M e m b r a n e s in Science a n d I n d u s t r y will be held from A u g u s t 2 9 - S e p t e m b e r 2 1994 in Tubingen, Germany. The scientific p r o g r a m m e i n c l u d e s invited l e c t u r e s on v a r i o u s topics, focused e s p e c i a l l y on functional membranes and carrier-assisted membrane p r o c e s s e s . P a p e r s for oral a n d p o s t e r p r e s e n t a t i o n s a r e solicited on the following topics: •
f u n d a m e n t a l s of m e m b r a n e p r o c e s s e s ;
•
p r e p a r a t i o n a n d c h a r a c t e r i z a t i o n of new synthetic membranes;
•
c h e m i c a l engineering a s p e c t s of m e m b r a n e separation processes;
•
m e m b r a n e s a n d m e m b r a n e p r o c e s s e s in i n d u s t r i a l applications;
•
m e m b r a n e s in b i o m e d i c a l s y s t e m s a n d analytic, diagnostic a n d s e n s o r i c devices;
•
m e m b r a n e s in e n e r g y c o n v e r s i o n a n d storage systems; and
•
Liquid m e m b r a n e r e m o v a l o f H2S The a p p l i c a t i o n of a liquid m e m b r a n e for selective removal of H2S from g a s e s also c o n t a i n i n g CO2 h a s b e e n i n v e s t i g a t e d b y r e s e a r c h e r s in The N e t h e r l a n d s (J. Membrane Sci., 82, 1993, p p 185-197). The liquid m e m b r a n e w a s filled with p u r e m e t h y l - d l - e t h a n o l - a m i n e (MDEA) w h i c h s h o w e d no r e a c t i o n with CO2. A theoretical model w a s u s e d to d e s c r i b e t h e c h e m i c a l e q u i l i b r i u m b e t w e e n the dissolved g a s a n d MDEA in the m e m b r a n e , a n d the p h y s i c a l e q u i l i b r i u m b e t w e e n the solute in the gas a n d the liquid p h a s e . H2S a n d CO2 fluxes were d e t e r m i n e d , a n d i n t e r p r e t e d with the theoretical model. To a l i m i t e d degree, r e a c t i o n w a s observed b e t w e e n H2S a n d t h e a m i n e , which r e s u l t s in a h i g h e r selectivity t h a n c a n be e x p e c t e d on t h e b a s i s of the p h y s i c a l solubility of CO2 a n d H2S. To f u r t h e r i n c r e a s e selectivity, it w a s d i s c u s s e d t h a t a solvent with higher H2S solubility c o u l d be used, or a c o m b i n a t i o n of t e r t i a r y a m i n e a n d a co-solvent which allows a f u r t h e r d i s s o c i a t i o n of the p h y s i c a l l y dissolved H2S.
Further Informatlon from: G.F. Versteeg, Faculty of Chemical Technology, University of Twente, P.O. Box 21 7, 7500 AE Enschede, The Netherlands.
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n e w a p p l i c a t i o n s of m e m b r a n e s a n d p r o c e s s e s . A u t h o r s who wish to s u b m i t a p a p e r for oral p r e s e n t a t i o n or a s a p o s t e r s h o u l d s u b m i t the title a n d a n a b s t r a c t of a b o u t 300 w o r d s (in English) before 31 October 1993.
Further Information from: DECHEMA e.V., Exhibitions and Congresses, P.O. Box 15 01 04, D-60061 Frankfurt a m Main, Germany. Tel: +69 75 64 2 4 1 / 2 4 2 / 2 4 3 . Fax: +69 75 64 201.
High r overy concentrator Amlcon, Inc h a s r e l e a s e d a n e w version of its C e n t r i p r e p c o n c e n t r a t o r s with a 50 000 m o l e c u l a r weight cut-off, for c o n c e n t r a t i n g , purifying or d e s a l t i n g s a m p l e s of u p to 15 ml. The non-fouling design is especially s u i t e d to c o n c e n t r a t i n g a n d d e s a l t i n g p a r t i c l e - l a d e n s a m p l e s . It is ideal for recovery of b i o m o l e c u l e s from cell c u l t u r e s u p e r n a t a n t s , lysates, e x t r a c t s or o t h e r biological samples. S a m p l e s of u p to 15 ml c a n be r a p i d l y c o n c e n t r a t e d to a s little a s 0.65 ml in 20--45 m i n u t e s . Integral d e a d s t o p p r o t e c t i o n p r e v e n t s filtration of s a m p l e to d r y n e s s . The u n i t ' s low-adsorptive m e m b r a n e provides over 90% p r o t e i n recovery a n d complete d e s a l t i n g with m i n i m a l d e n a t u r a t i o n or shear.
M e m b r a n e T e c h n o l o g y No. 3 6
News and Views m a t e r i a l s . The p e r f o r m a n c e of t h e 0.45 Ore, 85 m m discs, is s a i d to b e derived from the a s y m m e t r i c pore size d i s t r i b u t i o n of the ASYPOR m e m b r a n e . The m e m b r a n e , m a d e from m i x e d e s t e r s of cellulose, h a s p o r e s g r a d e d t h r o u g h o u t t h e d e p t h of the m e m b r a n e . The p o r e s on the u p s t r e a m surface, the o p e n side, a r e larger t h a n t h e p o r e s on t h e down s t r e a m side, t h e tight side. W h e n u s e d a s p a r t of the T r y p t o n e Bile Agar Direct Plate Method (DPM), this m e m b r a n e e n c o u r a g e s b a c t e r i a l growth a s a r e s u l t of its properties. DPM is u s e d b y m a n y food m a n u f a c t u r e r s b e c a u s e r e s u l t s c a n be o b t a i n e d in 24 h o u r s , a n d with l e s s effort t h a n t h e Most P r o b a b l e N u m b e r Test. Further Information from: Elaine Robinson, Marketing Services Assistant, domnlck hunter Ltd, Process Division, Durham Road, Birtley, Co. Durham DH3 2SF, UK. Tel: +44 (0)91 410 5121. Fax: +44 (0)91 410 5312.
RO l e a c h a t e treatment systems distributed by US Filter
C e n t r i p r e p c o n c e n t r a t o r s c a n be u s e d in m o s t s t a n d a r d c e n t r i f u g e s with fixed-angle or s w l n g i n g - b u c k e t r o t o r s a n d 50 ml t u b e adapter. They a r e also a v a i l a b l e in 3000, 10 000, 30 000 a n d 100 000 MW cut-offs. Further information from: Amlcon, Inc, 72 Cherry Hill Drive, Beverly, MA 01915, USA. Tel: +1 508 777 3622. Fax: +1 506 777 6294.
Rapid E. c o l i . testing using membrane discs D o m n i c k h u n t e r Process Division h a s w o r k e d in close alliance with m a j o r food m a n u f a c t u r e r s to identify a specific o p p o r t u n i t y for its ASYPOR m e m b r a n e . The m e m b r a n e h a s p r o v e n to be very s u c c e s s f u l for the e n u m e r a t i o n of Escherlchla coll in foods a n d r a w
M e m b r a n e T e c h n o l o g y No. 3 6
Rochem S e p a r a t i o n S y s t e m s , a s u b s i d i a r y of the I n t e r n a t i o n a l R o c h e m Group, h a s a n n o u n c e d the g r a n t i n g of exclusive US d i s t r i b u t i o n r i g h t s for the c o m p a n y ' s reverse o s m o s i s l e a c h a t e t r e a t m e n t e q u i p m e n t to US Filter Corp, a l e a d i n g s u p p l i e r of leachate treatment systems. R o c h e m ' s reverse o s m o s i s l e a c h a t e t r e a t m e n t e q u i p m e n t u s e s t h e p a t e n t e d Disc Tube TM m e m b r a n e m o d u l e technology, i n t r o d u c e d in t h e USA a b o u t 2 y e a r s ago. R o c h e m is c u r r e n t l y p r o c e s s i n g over 1 million g a l l o n s of landflU l e a c h a t e p e r d a y in Europe. The p a t e n t e d Disc Tube m e m b r a n e m o d u l e s - c o m p r i s e d of u l t r a s o n i c a l l y w e l d e d o c t a g o n a l m e m b r a n e c u s h i o n s , h y d r a u l i c c a r r i e r discs, e n d flanges a n d t u b u l a r p r e s s u r e v e s s e l s m a r e c a p a b l e of p r o c e s s i n g large v o l u m e s of r a w l e a c h a t e a n d recovering p u r e water, w h i c h c a n be r e u s e d or r e t u r n e d to the e n v i r o n m e n t . The m o d u l e s remove i n o r g a n i c m a t e r i a l s from the leachate; i n o r g a n i c s a l t s a r e n o r m a l l y r e d u c e d 99% a n d h e a v y m e t a l s c a n be removed to below d e t e c t i o n levels. Organic m a t e r i a l s s u c h as p e s t i c i d e s a n d h e r b i c i d e s , a r e also removed. The m o d u l e s p r e v e n t the p a s s a g e of biological m a t e r i a l , f e a t u r e a u t o m a t i c o p e r a t i o n a n d r e q u i r e m i n i m a l o p e r a t o r attention. Further information from: Stan Karrs, US Filter, 181 Thorn Hill Road, Warrendale, PA 15086-0627, USA. Tel: +1 412 772 0044.
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Further Informatlon from: Elga Ltd, High Street, Lane End, High Wycombe, Buckinghamshire, HP14 3JH, UK. Tel: +44 (0)494 881393. Fax: +44 (0)494 881007.
Call for p a p e r s The 7th I n t e r n a t i o n a l S y m p o s i u m on S y n t h e t i c M e m b r a n e s in Science a n d I n d u s t r y will be held from A u g u s t 2 9 - S e p t e m b e r 2 1994 in Tubingen, Germany. The scientific p r o g r a m m e i n c l u d e s invited l e c t u r e s on v a r i o u s topics, focused e s p e c i a l l y on functional membranes and carrier-assisted membrane p r o c e s s e s . P a p e r s for oral a n d p o s t e r p r e s e n t a t i o n s a r e solicited on the following topics: •
f u n d a m e n t a l s of m e m b r a n e p r o c e s s e s ;
•
p r e p a r a t i o n a n d c h a r a c t e r i z a t i o n of new synthetic membranes;
•
c h e m i c a l engineering a s p e c t s of m e m b r a n e separation processes;
•
m e m b r a n e s a n d m e m b r a n e p r o c e s s e s in i n d u s t r i a l applications;
•
m e m b r a n e s in b i o m e d i c a l s y s t e m s a n d analytic, diagnostic a n d s e n s o r i c devices;
•
m e m b r a n e s in e n e r g y c o n v e r s i o n a n d storage systems; and
•
Liquid m e m b r a n e r e m o v a l o f H2S The a p p l i c a t i o n of a liquid m e m b r a n e for selective removal of H2S from g a s e s also c o n t a i n i n g CO2 h a s b e e n i n v e s t i g a t e d b y r e s e a r c h e r s in The N e t h e r l a n d s (J. Membrane Sci., 82, 1993, p p 185-197). The liquid m e m b r a n e w a s filled with p u r e m e t h y l - d l - e t h a n o l - a m i n e (MDEA) w h i c h s h o w e d no r e a c t i o n with CO2. A theoretical model w a s u s e d to d e s c r i b e t h e c h e m i c a l e q u i l i b r i u m b e t w e e n the dissolved g a s a n d MDEA in the m e m b r a n e , a n d the p h y s i c a l e q u i l i b r i u m b e t w e e n the solute in the gas a n d the liquid p h a s e . H2S a n d CO2 fluxes were d e t e r m i n e d , a n d i n t e r p r e t e d with the theoretical model. To a l i m i t e d degree, r e a c t i o n w a s observed b e t w e e n H2S a n d t h e a m i n e , which r e s u l t s in a h i g h e r selectivity t h a n c a n be e x p e c t e d on t h e b a s i s of the p h y s i c a l solubility of CO2 a n d H2S. To f u r t h e r i n c r e a s e selectivity, it w a s d i s c u s s e d t h a t a solvent with higher H2S solubility c o u l d be used, or a c o m b i n a t i o n of t e r t i a r y a m i n e a n d a co-solvent which allows a f u r t h e r d i s s o c i a t i o n of the p h y s i c a l l y dissolved H2S.
Further Informatlon from: G.F. Versteeg, Faculty of Chemical Technology, University of Twente, P.O. Box 21 7, 7500 AE Enschede, The Netherlands.
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n e w a p p l i c a t i o n s of m e m b r a n e s a n d p r o c e s s e s . A u t h o r s who wish to s u b m i t a p a p e r for oral p r e s e n t a t i o n or a s a p o s t e r s h o u l d s u b m i t the title a n d a n a b s t r a c t of a b o u t 300 w o r d s (in English) before 31 October 1993.
Further Information from: DECHEMA e.V., Exhibitions and Congresses, P.O. Box 15 01 04, D-60061 Frankfurt a m Main, Germany. Tel: +69 75 64 2 4 1 / 2 4 2 / 2 4 3 . Fax: +69 75 64 201.
High r overy concentrator Amlcon, Inc h a s r e l e a s e d a n e w version of its C e n t r i p r e p c o n c e n t r a t o r s with a 50 000 m o l e c u l a r weight cut-off, for c o n c e n t r a t i n g , purifying or d e s a l t i n g s a m p l e s of u p to 15 ml. The non-fouling design is especially s u i t e d to c o n c e n t r a t i n g a n d d e s a l t i n g p a r t i c l e - l a d e n s a m p l e s . It is ideal for recovery of b i o m o l e c u l e s from cell c u l t u r e s u p e r n a t a n t s , lysates, e x t r a c t s or o t h e r biological samples. S a m p l e s of u p to 15 ml c a n be r a p i d l y c o n c e n t r a t e d to a s little a s 0.65 ml in 20--45 m i n u t e s . Integral d e a d s t o p p r o t e c t i o n p r e v e n t s filtration of s a m p l e to d r y n e s s . The u n i t ' s low-adsorptive m e m b r a n e provides over 90% p r o t e i n recovery a n d complete d e s a l t i n g with m i n i m a l d e n a t u r a t i o n or shear.
M e m b r a n e T e c h n o l o g y No. 3 6
News and Views m a t e r i a l s . The p e r f o r m a n c e of t h e 0.45 Ore, 85 m m discs, is s a i d to b e derived from the a s y m m e t r i c pore size d i s t r i b u t i o n of the ASYPOR m e m b r a n e . The m e m b r a n e , m a d e from m i x e d e s t e r s of cellulose, h a s p o r e s g r a d e d t h r o u g h o u t t h e d e p t h of the m e m b r a n e . The p o r e s on the u p s t r e a m surface, the o p e n side, a r e larger t h a n t h e p o r e s on t h e down s t r e a m side, t h e tight side. W h e n u s e d a s p a r t of the T r y p t o n e Bile Agar Direct Plate Method (DPM), this m e m b r a n e e n c o u r a g e s b a c t e r i a l growth a s a r e s u l t of its properties. DPM is u s e d b y m a n y food m a n u f a c t u r e r s b e c a u s e r e s u l t s c a n be o b t a i n e d in 24 h o u r s , a n d with l e s s effort t h a n t h e Most P r o b a b l e N u m b e r Test. Further Information from: Elaine Robinson, Marketing Services Assistant, domnlck hunter Ltd, Process Division, Durham Road, Birtley, Co. Durham DH3 2SF, UK. Tel: +44 (0)91 410 5121. Fax: +44 (0)91 410 5312.
RO l e a c h a t e treatment systems distributed by US Filter
C e n t r i p r e p c o n c e n t r a t o r s c a n be u s e d in m o s t s t a n d a r d c e n t r i f u g e s with fixed-angle or s w l n g i n g - b u c k e t r o t o r s a n d 50 ml t u b e adapter. They a r e also a v a i l a b l e in 3000, 10 000, 30 000 a n d 100 000 MW cut-offs. Further information from: Amlcon, Inc, 72 Cherry Hill Drive, Beverly, MA 01915, USA. Tel: +1 508 777 3622. Fax: +1 506 777 6294.
Rapid E. c o l i . testing using membrane discs D o m n i c k h u n t e r Process Division h a s w o r k e d in close alliance with m a j o r food m a n u f a c t u r e r s to identify a specific o p p o r t u n i t y for its ASYPOR m e m b r a n e . The m e m b r a n e h a s p r o v e n to be very s u c c e s s f u l for the e n u m e r a t i o n of Escherlchla coll in foods a n d r a w
M e m b r a n e T e c h n o l o g y No. 3 6
Rochem S e p a r a t i o n S y s t e m s , a s u b s i d i a r y of the I n t e r n a t i o n a l R o c h e m Group, h a s a n n o u n c e d the g r a n t i n g of exclusive US d i s t r i b u t i o n r i g h t s for the c o m p a n y ' s reverse o s m o s i s l e a c h a t e t r e a t m e n t e q u i p m e n t to US Filter Corp, a l e a d i n g s u p p l i e r of leachate treatment systems. R o c h e m ' s reverse o s m o s i s l e a c h a t e t r e a t m e n t e q u i p m e n t u s e s t h e p a t e n t e d Disc Tube TM m e m b r a n e m o d u l e technology, i n t r o d u c e d in t h e USA a b o u t 2 y e a r s ago. R o c h e m is c u r r e n t l y p r o c e s s i n g over 1 million g a l l o n s of landflU l e a c h a t e p e r d a y in Europe. The p a t e n t e d Disc Tube m e m b r a n e m o d u l e s - c o m p r i s e d of u l t r a s o n i c a l l y w e l d e d o c t a g o n a l m e m b r a n e c u s h i o n s , h y d r a u l i c c a r r i e r discs, e n d flanges a n d t u b u l a r p r e s s u r e v e s s e l s m a r e c a p a b l e of p r o c e s s i n g large v o l u m e s of r a w l e a c h a t e a n d recovering p u r e water, w h i c h c a n be r e u s e d or r e t u r n e d to the e n v i r o n m e n t . The m o d u l e s remove i n o r g a n i c m a t e r i a l s from the leachate; i n o r g a n i c s a l t s a r e n o r m a l l y r e d u c e d 99% a n d h e a v y m e t a l s c a n be removed to below d e t e c t i o n levels. Organic m a t e r i a l s s u c h as p e s t i c i d e s a n d h e r b i c i d e s , a r e also removed. The m o d u l e s p r e v e n t the p a s s a g e of biological m a t e r i a l , f e a t u r e a u t o m a t i c o p e r a t i o n a n d r e q u i r e m i n i m a l o p e r a t o r attention. Further information from: Stan Karrs, US Filter, 181 Thorn Hill Road, Warrendale, PA 15086-0627, USA. Tel: +1 412 772 0044.
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