- Email: [email protected]
UF membranes produce drinking water for US communities
FEATURE
their associated storage times. He compared the effects of prion and leukocyte filtered red cells with leukocyte-only filtered red cells, and also compared these results to historical data. These preliminary results have demonstrated that blood filtered with the Pall Leukotrap Affinity prion reduction filter is substantially equivalent to control blood units from a safety and efficacy point of view.
Blood centres Since a majority of blood transfused in the industrialized world is currently leukocyte reduced, a filtration approach can swiftly and easily fit into routine operating (cGMP) practice already in use in blood centres around the world. It is expected that the new technology will meet the requirements of the Council of Europe for a CE mark and will be ready for operational trial in Europe beginning in early 2005. The company continues to study the new technology and will release additional results on the animal model research in the coming months. It says that it is also planning to conduct clinical surveillance studies after receiving the CE mark to continue to add to the knowledge about transmission of prion diseases.
Boon to public health and safety Although the incidence of new cases of vCJD have appeared to slow down over the past few years, many experts believe that we should not be lulled into a false sense of security. Since the disease has an unknown incubation period without clinical sign or symptoms, a proportion of the population could be harbouring vCJD and acting as blood donors. The existence of sub-clinical prion carriers raises concerns of a human-to-human wave of transmission, posing a potential threat to the safety of the blood supply. These experts contend that the possibility of further increases in the number of cases, even a human epidemic of vCJD, cannot be dismissed. Since the risk of vCJD is not restricted to the UK, the examination of the history of blood donation may be required in other European countries and elsewhere. Pall is also studying the new technology as a potential detection device to identify ‘Mad Cow Disease’ in cattle, as a means to help protect the food supply. According to an April 2004 Consensus Conference on Transmissible
Spongiform Encephalopathies, there is currently no reliable or practical way available to determine the presence of BSE and vCJD in food or in living asymptomatic animals or people.
Prion diseases Prion diseases are fatal, neuro-degenerative diseases, referred to as Transmissible Spongiform Encephalopathies that affect both humans and animals. They include scrapie in sheep, bovine spongiform encephalopathy in cattle and vCJD in humans. It is estimated that the incubation period (prior to clinical symptoms) for vCJD may be anywhere between 10 to 20 years. Since the first human case of vCJD was identified in 1994, there have been 154 confirmed cases worldwide with the vast majority (143) in the UK. On 17 December 2003, the Secretary of Health of the UK announced the first case of a patient dying from vCJD, received from a blood transfusion during an operation.
Contacts: Pall Corp, 2200 Northern Boulevard, East Hills, NY 11548, USA. Tel: +1 516 484 5400, Fax: +1 516 484 3649.
UF membranes produce drinking water for US communities Edited by Simon Atkinson This brief case study provides details of a number of water treatment plants in the USA that are using Koch Membrane Systems' UF technology. In many communities north of San Antonio, Texas, USA, the demand for drinking water continues to grow. To meet this need and provide potable water in line with the turbidity and micro-organism requirements of the Safe Drinking Water Act, Canyon Regional Water Authority (CRWA) is expanding its Lake Dunlap water treatment plant using ultrafiltration (UF) technology from Koch
10
Membrane Systems (KMS), Wilmington, Massachusetts.
Turbidity During the Spring of 2002, CRWA started up a UF system from KMS rated at over 15 100 m 3 (4 million gallons) per day. This system consists of two skids each containing 48 UF
cartridges, 200 mm (8 inch) in diameter, and was designed to be expanded to about 38 000 m 3 (10 million gallons) a days by adding extra skids. Turbidity can be a problem at the Lake Dunlap plant, which is fed by a river. Shortly after the system became operational, heavy rains resulted in serious flooding, which caused very high turbidity spikes in the feed water to the UF. The ability of the KMS system to continue producing great quality water during this challenging period confirmed the wisdom of selecting a KMS pressure cartridge system to treat this surface waer supply.
Membrane Technology October 2004
FEATURE
Expansion CRWA knew from the outset that it would expand the Lake Dunlap plant and had constructed a building capable of housing 6 UF skids. Late in 2002, the authority decided to move forward with the planned expansion. The UF equipment was purchased in 2003, and will increase the system's capacity to more than 56 800 m3 (15 million gallons) per day. The system will consist of six skids, each able to hold 44 of the new PMPW-10 UF cartridges from KMS. The addition of cartridges to the open positions on the new skids will increase that capacity by another 10%.
Advantages According to CRWA, one of the big advantages of the PMPW-10 cartridge is that the same floor space and building used to accommodate 6 stages in the initial system design will soon produce much more water. This is because the PMPW-10 cartridges contain 60% more membrane surface area than the 200-mm (8-inch) diameter cartridges used originally. Each new skid will be able to produce 30% more water than the original skid, yet each skid will occupy the same amount of floor space. The PMPW-10 used at CRWA is about 1.8 m (72-inches) in length, and contains about 80 m2 (870 ft2) of membrane. The same cartridge is also available in a length of around 1.2 m (48 inches), containing 51 m2 (550 ft2) of membrane.
Polysulphone Both cartridges contain thousands of hollow fibres made from polysulphone, a membrane material that has been in use in membrane water treatment plants around the world for over a decade. Polysulphone can tolerate a broad pH range, and can withstand chlorine at high pH giving it distinct advantages when it is time to chemically clean the membranes. The hollow fibres are extremely effective in reducing turbidity and routinely achieve less than 0.1 NTU on a wide variety of water supplies. With a molecular weight cutoff of 100 000, the membranes can provide 4-log removal of Cryptosporidium, Giardia and viruses, thereby helping operators to comply with the Safe Drinking Water Act.
Iron and manganese Recently a community in Massachusetts has selected the PMPW-10 cartridge to treat drinking water from the town wells. The town of Franklin has water that con-
Membrane Technology October 2004
tains iron and manganese. The pretreatment step involves adding ozone to oxidize the iron and manganese. The KMS hollow fibres in the 1.2-m (48-inch) long PMPW-10 cartridges are extremely effective in removing the precipitated iron and manganese oxides, says KMS. The town will use two skids, each containing 16 PMPW-10 cartridges, to produce about 4500 m 3 (1.2 million gallons) of potable water per day.
Other communities This approach to iron and manganese removal has been employed successfully in other Massachusetts communities using smaller KMS cartridges. The Town of Littleton began using a KMS UF system to remove iron and manganese from well water under the influence of surface water during 1997, and is still using the original cartridges today. Like Franklin, this system also uses ozone pretreatment to convert the iron and manganese to insoluble iron oxide and manganese oxide. Like the PMPW-10, the membranes are also made from polysulphone, but they are housed in cartridges that are 127 mm (5 inches) in diameter and about 1092 mm (43 inches) long. Four skids containing 50 cartridges, produce 5300 m3 (1.4 million gallons) of potable water a day from a well that once was shut down.
Minimizing waste To minimize waste, a membrane wastewater recovery system was also installed at the Littleton plant. The concentrated waste from the water treatment system is directed to a wastewater storage tank. A wastewater treatment skid with UF cartridges treats the collected water, further concentrating the iron and manganese oxides. The highly concentrated slurry of oxides in the tank is periodically pumped to drying beds. Approximately 99.9% of the feed water is recovered in this way.
Smaller buildings By using the larger diameter PMPW-10 cartridge, smaller buildings can now be used to house the UF systems. Water treatment plants based on PMPW-10 systems are 30-50% smaller than those that house older 127-mm (5-inch) or 203-mm (8-inch) systems, and will process the same amount of drinking water at a significant savings in new construction costs.
Reverse osmosis Just as larger diameter UF cartridges have produced higher flows at lower cost in low-pressure
Tapping into public opinion: consumer awareness is one of the key drivers behind filtration companies’ aim of delivering cleaner water.
UF systems, the same is true of reverse osmosis (RO) membrane systems using larger diameter elements from KMS. While standard RO and nanofiltration elements are 203 mm (8 inches) in diameter and 1016 mm (40-inches) long, the MegaMagnum elements from KMS are 457 mm (18 inches) in diameter and 1524 mm (60 inches) long, allowing for approximately seven times more active membrane area per element. Compared with standard 203-mm (8-inch) diameter RO elements, the greater membrane area of the MegaMagnum RO element requires fewer elements and pressure vessels for a given flow rate. This saves time in the loading of elements at system commissioning, as well as providing the obvious benefits of fewer fittings, fewer fixtures and smaller plant footprint, says KMS.
Wastewater reclamation Orange County in California has recently completed testing of a MegaMagnum RO element for wastewater reclamation, and Scottsdale in Arizona has had a prototype under evaluation for over 1 year. The Metropolitan Water District of Southern California plans to start up a demonstration pilot plant later this year that will use several MegaMagnum RO elements housed in three pressure vessels. KMS claims that the MegaMagnum RO element is the world's first 457-mm (18-inch) diameter brackish-water spiral membrane. This dramatic increase in element size and membrane surface area greatly reduces the footprint and cost of the installed RO system.
Contact: Koch Membrane Systems Inc, 850 Main Street, Wilmington, MA 01887-3388, USA. Tel: +1 978 657 4250, Fax: +1 978 657 5208, Email: [email protected].
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their associated storage times. He compared the effects of prion and leukocyte filtered red cells with leukocyte-only filtered red cells, and also compared these results to historical data. These preliminary results have demonstrated that blood filtered with the Pall Leukotrap Affinity prion reduction filter is substantially equivalent to control blood units from a safety and efficacy point of view.
Blood centres Since a majority of blood transfused in the industrialized world is currently leukocyte reduced, a filtration approach can swiftly and easily fit into routine operating (cGMP) practice already in use in blood centres around the world. It is expected that the new technology will meet the requirements of the Council of Europe for a CE mark and will be ready for operational trial in Europe beginning in early 2005. The company continues to study the new technology and will release additional results on the animal model research in the coming months. It says that it is also planning to conduct clinical surveillance studies after receiving the CE mark to continue to add to the knowledge about transmission of prion diseases.
Boon to public health and safety Although the incidence of new cases of vCJD have appeared to slow down over the past few years, many experts believe that we should not be lulled into a false sense of security. Since the disease has an unknown incubation period without clinical sign or symptoms, a proportion of the population could be harbouring vCJD and acting as blood donors. The existence of sub-clinical prion carriers raises concerns of a human-to-human wave of transmission, posing a potential threat to the safety of the blood supply. These experts contend that the possibility of further increases in the number of cases, even a human epidemic of vCJD, cannot be dismissed. Since the risk of vCJD is not restricted to the UK, the examination of the history of blood donation may be required in other European countries and elsewhere. Pall is also studying the new technology as a potential detection device to identify ‘Mad Cow Disease’ in cattle, as a means to help protect the food supply. According to an April 2004 Consensus Conference on Transmissible
Spongiform Encephalopathies, there is currently no reliable or practical way available to determine the presence of BSE and vCJD in food or in living asymptomatic animals or people.
Prion diseases Prion diseases are fatal, neuro-degenerative diseases, referred to as Transmissible Spongiform Encephalopathies that affect both humans and animals. They include scrapie in sheep, bovine spongiform encephalopathy in cattle and vCJD in humans. It is estimated that the incubation period (prior to clinical symptoms) for vCJD may be anywhere between 10 to 20 years. Since the first human case of vCJD was identified in 1994, there have been 154 confirmed cases worldwide with the vast majority (143) in the UK. On 17 December 2003, the Secretary of Health of the UK announced the first case of a patient dying from vCJD, received from a blood transfusion during an operation.
Contacts: Pall Corp, 2200 Northern Boulevard, East Hills, NY 11548, USA. Tel: +1 516 484 5400, Fax: +1 516 484 3649.
UF membranes produce drinking water for US communities Edited by Simon Atkinson This brief case study provides details of a number of water treatment plants in the USA that are using Koch Membrane Systems' UF technology. In many communities north of San Antonio, Texas, USA, the demand for drinking water continues to grow. To meet this need and provide potable water in line with the turbidity and micro-organism requirements of the Safe Drinking Water Act, Canyon Regional Water Authority (CRWA) is expanding its Lake Dunlap water treatment plant using ultrafiltration (UF) technology from Koch
10
Membrane Systems (KMS), Wilmington, Massachusetts.
Turbidity During the Spring of 2002, CRWA started up a UF system from KMS rated at over 15 100 m 3 (4 million gallons) per day. This system consists of two skids each containing 48 UF
cartridges, 200 mm (8 inch) in diameter, and was designed to be expanded to about 38 000 m 3 (10 million gallons) a days by adding extra skids. Turbidity can be a problem at the Lake Dunlap plant, which is fed by a river. Shortly after the system became operational, heavy rains resulted in serious flooding, which caused very high turbidity spikes in the feed water to the UF. The ability of the KMS system to continue producing great quality water during this challenging period confirmed the wisdom of selecting a KMS pressure cartridge system to treat this surface waer supply.
Membrane Technology October 2004
FEATURE
Expansion CRWA knew from the outset that it would expand the Lake Dunlap plant and had constructed a building capable of housing 6 UF skids. Late in 2002, the authority decided to move forward with the planned expansion. The UF equipment was purchased in 2003, and will increase the system's capacity to more than 56 800 m3 (15 million gallons) per day. The system will consist of six skids, each able to hold 44 of the new PMPW-10 UF cartridges from KMS. The addition of cartridges to the open positions on the new skids will increase that capacity by another 10%.
Advantages According to CRWA, one of the big advantages of the PMPW-10 cartridge is that the same floor space and building used to accommodate 6 stages in the initial system design will soon produce much more water. This is because the PMPW-10 cartridges contain 60% more membrane surface area than the 200-mm (8-inch) diameter cartridges used originally. Each new skid will be able to produce 30% more water than the original skid, yet each skid will occupy the same amount of floor space. The PMPW-10 used at CRWA is about 1.8 m (72-inches) in length, and contains about 80 m2 (870 ft2) of membrane. The same cartridge is also available in a length of around 1.2 m (48 inches), containing 51 m2 (550 ft2) of membrane.
Polysulphone Both cartridges contain thousands of hollow fibres made from polysulphone, a membrane material that has been in use in membrane water treatment plants around the world for over a decade. Polysulphone can tolerate a broad pH range, and can withstand chlorine at high pH giving it distinct advantages when it is time to chemically clean the membranes. The hollow fibres are extremely effective in reducing turbidity and routinely achieve less than 0.1 NTU on a wide variety of water supplies. With a molecular weight cutoff of 100 000, the membranes can provide 4-log removal of Cryptosporidium, Giardia and viruses, thereby helping operators to comply with the Safe Drinking Water Act.
Iron and manganese Recently a community in Massachusetts has selected the PMPW-10 cartridge to treat drinking water from the town wells. The town of Franklin has water that con-
Membrane Technology October 2004
tains iron and manganese. The pretreatment step involves adding ozone to oxidize the iron and manganese. The KMS hollow fibres in the 1.2-m (48-inch) long PMPW-10 cartridges are extremely effective in removing the precipitated iron and manganese oxides, says KMS. The town will use two skids, each containing 16 PMPW-10 cartridges, to produce about 4500 m 3 (1.2 million gallons) of potable water per day.
Other communities This approach to iron and manganese removal has been employed successfully in other Massachusetts communities using smaller KMS cartridges. The Town of Littleton began using a KMS UF system to remove iron and manganese from well water under the influence of surface water during 1997, and is still using the original cartridges today. Like Franklin, this system also uses ozone pretreatment to convert the iron and manganese to insoluble iron oxide and manganese oxide. Like the PMPW-10, the membranes are also made from polysulphone, but they are housed in cartridges that are 127 mm (5 inches) in diameter and about 1092 mm (43 inches) long. Four skids containing 50 cartridges, produce 5300 m3 (1.4 million gallons) of potable water a day from a well that once was shut down.
Minimizing waste To minimize waste, a membrane wastewater recovery system was also installed at the Littleton plant. The concentrated waste from the water treatment system is directed to a wastewater storage tank. A wastewater treatment skid with UF cartridges treats the collected water, further concentrating the iron and manganese oxides. The highly concentrated slurry of oxides in the tank is periodically pumped to drying beds. Approximately 99.9% of the feed water is recovered in this way.
Smaller buildings By using the larger diameter PMPW-10 cartridge, smaller buildings can now be used to house the UF systems. Water treatment plants based on PMPW-10 systems are 30-50% smaller than those that house older 127-mm (5-inch) or 203-mm (8-inch) systems, and will process the same amount of drinking water at a significant savings in new construction costs.
Reverse osmosis Just as larger diameter UF cartridges have produced higher flows at lower cost in low-pressure
Tapping into public opinion: consumer awareness is one of the key drivers behind filtration companies’ aim of delivering cleaner water.
UF systems, the same is true of reverse osmosis (RO) membrane systems using larger diameter elements from KMS. While standard RO and nanofiltration elements are 203 mm (8 inches) in diameter and 1016 mm (40-inches) long, the MegaMagnum elements from KMS are 457 mm (18 inches) in diameter and 1524 mm (60 inches) long, allowing for approximately seven times more active membrane area per element. Compared with standard 203-mm (8-inch) diameter RO elements, the greater membrane area of the MegaMagnum RO element requires fewer elements and pressure vessels for a given flow rate. This saves time in the loading of elements at system commissioning, as well as providing the obvious benefits of fewer fittings, fewer fixtures and smaller plant footprint, says KMS.
Wastewater reclamation Orange County in California has recently completed testing of a MegaMagnum RO element for wastewater reclamation, and Scottsdale in Arizona has had a prototype under evaluation for over 1 year. The Metropolitan Water District of Southern California plans to start up a demonstration pilot plant later this year that will use several MegaMagnum RO elements housed in three pressure vessels. KMS claims that the MegaMagnum RO element is the world's first 457-mm (18-inch) diameter brackish-water spiral membrane. This dramatic increase in element size and membrane surface area greatly reduces the footprint and cost of the installed RO system.
Contact: Koch Membrane Systems Inc, 850 Main Street, Wilmington, MA 01887-3388, USA. Tel: +1 978 657 4250, Fax: +1 978 657 5208, Email: [email protected].
11