WorldWideScience

Sample records for program baghouse filtration

  1. ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) PROGRAM; BAGHOUSE FILTRATION PRODUCTS

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) Environmental Technology Verification (ETV) Program evaluates the performance of innovative air, water, pollution prevention and monitoring technologies that have the potential to improve human health and the environment. This techno...

  2. Baghouse filtration products verification

    Energy Technology Data Exchange (ETDEWEB)

    Mycock, J.C.; Turner, J.H.; VanOsdell, D.W.; Farmer, J.R.; Brna, T.G.

    1998-11-01

    The paper introduces EPA`s Air Pollution Control Technology Verification (APCT) program and then focuses on the immediate objective of the program: laboratory performance verification of cleanable filter media intended for the control of fine particulate emissions. Data collected during the laboratory verification testing, which simulates operation in full-scale fabric filters, will be used to show expected performance for collection of particles {le} 2.5 micrometers in diameter.

  3. Baghouse Test Program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    The purpose of this test program was to evaluate the application of a baghouse to an FBC system and provide data to be used in future fabric filter designs. The goals of the program were to: determine mass collection efficiencies of baghouse; determine outlet emissions in terms of lbs particulate/10/sup 6/ Btu fired as compared with the New Source Performance Standard of 0.03 lbs/10/sup 6/ Btu; determine bag ..delta..P and other operating characteristics of the baghouse through data and observation; compare baghouse performance in several cleaning modes and at several filtration ratios; and evaluate operational problems in the use of fabric filters as final dust collection systems on FBC units. Results indicate that in the shake only mode of the baghouse operated with a mass collection efficiency of 99.7% or better with inlet dust loadings ranging from 2.5 to as great as 17.5 gr/SCF independent of a/c ratio. Regardless of variances in a/c ratios or inlet dust loading or chemical composition the baghouse outlet emissions remained constant meeting or surpassing the new EPA source performance standard of 0.03 lbs particulate/10/sup 6/ Btu in every sampling case. Although bag ..delta..P values varied with inlet dust loading, typical bag ..delta..P values ranged from a starting value of 2.3'' w.c. after cleaning to 4.8'' w.c. after 60 mins. of filtering at an a/c of 2.5 ACFM/ft/sup 2/ and from 5.4'' w.c. to 8.0'' w.c. or more after 30 mins. at an a/c of 4.0. Despite the excessive dust loadings and numerous passes through the acid dewpoint during startups the shake only bags performed well. This reflects the care taken to precoat the bags with limestone dust and to minimize the exposure to the acid dewpoint by rapid heat up.

  4. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - INSPEC FIBRES 5512BRF FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - STANDARD FILTER CORPORATION PE16ZU FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  6. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - ALBANY INTERNATIONAL CORP. INDUSTRIAL PROCESS TECHNOLOGIES PRIMATEX PLUS I FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  7. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - W.L. GORE & ASSOCIATES, INC. L4347 FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  8. Baghouse operation and maintenance user and fabric filtration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This group of papers from the ninth in a series of A and WMA biannual Fabric Filtration conferences is of particular interest to engineers, operators, managers, and vendors of baghouses because it covers the topics from the perspective of the user. It features such topics as cement applications, boilers and incineration, and metals applications.

  9. ENVIRONMENTAL TECHNOLOGY VERIFICATION OF BAGHOUSE FILTRATION PRODUCTS

    Science.gov (United States)

    The Environmental Technology Verification Program (ETV) was started by EPA in 1995 to generate independent credible data on the performance of innovative technologies that have potential to improve protection of public health and the environment. ETV does not approve or certify p...

  10. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, TETRATEC PTFE PRODUCTS, TETRATEX 6212 FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  11. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT--BAGHOUSE FILTRATION PRODUCTS, W.L. GORE ASSOC., INC.

    Science.gov (United States)

    The U.S. Environmental Protection Agency Air Pollution Control Technology (APCT) Verification Center evaluates the performance of baghouse filtration products used primarily to control PM2.5 emissions. This verification statement summarizes the test results for W.L. Gore & Assoc....

  12. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, POLYMER GROUP, INC., DURAPEX PET FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  13. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, BHA GROUP, INC., QP131 FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  14. Environmental Technology Verification, Baghouse Filtration Products TTG Inc., TG800 Filtration Media (Tested August 2012)

    Science.gov (United States)

    Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

  15. Environmental Technology Verification; Baghouse Filtration Products TTG Inc., TG100 Filtration Media (Tested August 2012)

    Science.gov (United States)

    Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

  16. Environmental Technology Verification--Baghouse Filtration Products: GE Energy QG061 Filtration Media (Tested September 2008)

    Science.gov (United States)

    This report reviews the filtration and pressure drop performance of GE Energy's QG061 filtration media. Environmental Technology Verification (ETV) testing of this technology/product was conducted during a series of tests in September 2008. The objective of the ETV Program is to ...

  17. Apparatus and method for the control of the precoating of an effluent filtration baghouse utilizing clean side pressure measurement

    Energy Technology Data Exchange (ETDEWEB)

    Cera, T.J.; Price, C.A.

    1984-08-07

    A method and apparatus for the control of the precoating process employed in an effluent filtration baghouse are described. An electrically operated pressure switch is provided to indicate the precoat duct vacuum pressure by measuring the vacuum pressure of the clean side of the baghouse. Should a precoat duct pressure insufficient to sustain the flow of precoat material be indicated, the pressure switch will halt the feed of precoat material into the precoat duct, thus avoiding the congestion of the precoat duct by the precoat material and the consequent inadequate precoating of the baghouse bags.

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS—SOUTHERN FILTER MEDIA, LLC, PE-16/M-SPES FILTER SAMPLE

    Science.gov (United States)

    The U.S. EPA has created the Environmental Technology Verification program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. The program tested the performance of baghouse filtrati...

  19. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS, W.L. GORE & ASSOCIATES, INC. LYSB3 FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size for particles equal to or smaller than...

  20. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, W.L. GORE & ASSOCIATES, INC., L4427 FILTER SAMPLE

    Science.gov (United States)

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  1. Effect of filtration velocity and filtration pressure drop on the bag-cleaning performance of a pulse-jet baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.J.; Tsai, M.L.; Lu, H.C.

    2000-01-01

    In this study the filtration velocity and filtration pressure drop at the beginning of bag cleaning were used as experimental parameters to evaluate the bag-cleaning performance of a pulse-jet baghouse. The effective residual pressure loss was used to indicate the cleaning performance after bag cleaning. Two different test dusts, fly ash and limestone, were used. The critical cleaning indices under different operation conditions for bag cleaning were also investigated. A critical average pulse overpressure was found to exist beyond which bag-cleaning performance did not improve much. It was found the filter's final filtration resistance is an important parameter to decide whether a Venturi is necessary for a good bag-cleaning performance or not. Use of a Venturi was found to increase the average pulse overpressure for a system with a filter's final resistance coefficient greater than about 500 Pa{center{underscore}dot}s/cm. However, no Venturi is recommended when the filter's final resistance coefficient is smaller than 500 Pa{center{underscore}dot}s/cm.

  2. Donaldson Company, Inc., Dura-Life #0701607 Filtration Media(Tested October 2011) (ETV Baghouse Filtration Products) Verification Report

    Science.gov (United States)

    Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

  3. TEST QA PLAN FOR THE VERIFICATION TESTING OF BAGHOUSE FILTRATION PRODUCTS

    Science.gov (United States)

    Baghouses and their accompanying filter media are a leading particulate control technique for industrial sources. Increasingly emphasis on higher removal efficiencies has helped the baghouse to be even more competitive when compared to other control devices. At present there is n...

  4. Laboratory measurements of the spatial distribution of gas velocities through seasoned baghouse fabrics throughout a simulated filtration cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kistler, W.G.; Steele, W.J.; Pontius, D.H.; Albano, R.K.

    1986-01-01

    The spatial distribution of the gas velocity across seasoned filter bag samples was measured with high resolution throughout a simulated filtration cycle. The samples were obtained from utility baghouses employing shake/deflate and reverse-gas cleaning. The tests simulated a filtration cycle with a constant air to cloth ratio of 2 acfm/ft/sup 2/ for a two-hour period with a gas having a mass loading of 3 gr/ft/sup 3/. The spatial distribution of velocities was determined at selected times throughout the filtration cycle by measuring the amount of a fine fluorescent powder that was intermittently introduced as a tracer into the test aerosol. Results of these tests showed that the initial flow of gas was almost entirely through fractures in the dust cake resulting from the cleaning operation. As the filtration cycle progressed, the flow became more uniformly distributed over the filter surface.

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT--BAGHOUSE FILTRATION PRODUCTS, DONALDSON COMPANY, INC., 6282 FILTRATION MEDIA

    Science.gov (United States)

    The Environmental Technology Verification (ETV) Program, established by the U.S. EPA, is designed to accelerate the developmentand commercialization of new or improved technologies through third-party verification and reporting of performance. The Air Pollution Control Technology...

  6. Environmental Technology Verification: Baghouse Filtration Products--Donaldson Co., Inc., Tetratec #6255-3 Filtration Media

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

  7. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS--DONALDSON COMPANY, INC., TETRATEC #6255 FILTRATION MEDIA

    Science.gov (United States)

    The Environmental Technology Verification (ETV) Program, established by the U.S. EPA, is designed to accelerate the development and commercialization of new or improved technologies through third-party verification and reporting of performance. The Air Pollution Control Technolog...

  8. Environmental Technology Verification: Baghouse Filtration Products--TDC Filter Manufacturing, Inc., SB025 Filtration Media

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

  9. Environmental Technology Verification Report -- Baghouse filtration products, GE Energy QG061 filtration media ( tested May 2007)

    Science.gov (United States)

    EPA has created the Environmental Technology Verification Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. The Air Pollution Control Technology Verification Center, a cente...

  10. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS--DONALDSON COMPANY, INC. 6277 FILTRATION MEDIA

    Science.gov (United States)

    The U.S. Environmental Protection Agency has created the Environmental Technology Verification Program to facilitate the deployment of innovative or improved environmental technologies through high quality, peer reviewed data on technology performance to those involved in the des...

  11. Environmental Technology Verification: Baghouse Filtration Products--Sinoma Science & Technology Co. Ltd FT-806 Filtration Media

    Science.gov (United States)

    EPA created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. It seeks to achieve this goal by providing high-quality, peer r...

  12. Environmental Technology Verification Report and Statement for Baghouse Filtration Products, W. L. Gore & Associates, Inc. 5117 High Durability PPS Laminate Filtration Media (Tested March-April 2012)

    Science.gov (United States)

    Baghouses are air pollution control devices used to control particulate emissions from stationary sources and are among the technologies evaluated by the APCT Center. Baghouses and their accompanying filter media have long been one of the leading particulate control techniques fo...

  13. Environmental Technology Verification: Baghouse filtration products--W.L. Gore & Associates L3650 filtration media (tested November--December 2009)

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

  14. Environmental Technology Verification Report: Baghouse Filtration Products, Donaldson Company, Inc. Tetratex® 6277 Filtration Media (Tested March 2011)

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

  15. Environmental Technology Verification Report: Baghouse Filtration Products, Donaldson Company, Inc. Tetratex® 6262 Filtration Media (Tested March 2011)

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

  16. Environmental Technology Verification Report: Baghouse Filtration Products, Donaldson Company, Inc. Tetratex® 6282 Filtration Media (Tested March - April 2011)

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

  17. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS, BWF AMERICA, INC., GRADE 700 MPS POLYESTER FELT FILTER SAMPLE

    Science.gov (United States)

    EPA's National Risk Management Research Laboratory, through its Environmental Technology Verification Program, evaluated the performance of a bag house filtration product for use controlling PM2.5. The product was BWF America, Inc., filter fabric Grade 700 Polyester Felt. All tes...

  18. Pick the right baghouse material

    Energy Technology Data Exchange (ETDEWEB)

    Mycock, J.C. [ETS Inc., Roanoke, VA (United States)

    1999-07-01

    Power plant operators can make sure they select the right material for their baghouse by paying attention to a few important parameters. Advice is given on selection of filter bag and fabric type for baghouses. Flue gas temperature, both continuous operation and maximum surge temperatures is the single most important factor; flue gas chemistry must also be considered. A table lists a range of chemical and physical properties of 29 textiles fibres for filtration. 1 tab., 1 photo.

  19. Selecting baghouse dust collectors

    Energy Technology Data Exchange (ETDEWEB)

    Moore, S.; Rubak, J.; Jolin, M. [Farr Co., El Segundo, CA (United States)]|[Farr Co., Laval, Quebec (Canada)

    1997-04-01

    A thorough analysis of the dust to be captured and determination of specific application requirements are necessary when designing a baghouse collection system. Independent consultants specializing in pollution control equipment and manufacturers with experience in several types of collectors are possible sources of assistance. These experts typically have testing facilities to analyze the dust characteristics. This final article of a two-part series on baghouse design and selection concentrates on application considerations created by the type of dust handled, selecting the best filtration media, selecting the best filtration media, and determining the air-to-cloth (A/C) ratio. The first article discussed bag sizing and cleaning methods and housing and hopper designs.

  20. Arizona Public Service Company: the baghouse pilot program. Paper 81. 9. 1

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, E.; Vaklyes, J.; Osborn, D.; Singh, U.

    1981-01-01

    An evaluation of the precipitators and baghouses used at steam generators with boilers that are fueled by pulverized coal, is made. In order to prevent outages due to cleaning, the baghouse system was developed to replace precipitators. Fabric filters were used capable of reverse-air cleaning with mininmum of maintenance.

  1. The evolution and impact of testing baghouse filter performance.

    Science.gov (United States)

    Pham, Minh; Clark, Christina; Mckenna, John

    2012-08-01

    In 1995, the US. Environmental Protection Agency (EPA) initiated the Environmental Technology Verification (ETV) program for the purpose of generating both independent and credible performance verification of innovative technologies and helping to accelerate acceptance of these products into the marketplace to further benefit the environment and protect public health. The EPA has approved a testing protocol under this program to verify the performance of commercially available filtration products for pulse-jet baghouses in removingfine particulate matter (aerodynamic diameter<2.5 microm; PM2.5). This verification testing protocol was later used as a basis for the development of the American Society for Testing and Materials (ASTM) Method D6830-02 and the International Organization for Standardization (ISO) Method 11057. The South Coast Air Quality Management District (SCAQMD) in California and the EPA s Office of Air Quality Planning and Standards (OAQPS) highly encourage the use of ETV/ASTM-verified filtration media. This paper highlights the evolution of the standard test methods, the EPA's and SCAQMD's regulatory activities, the benefits of using verified filtration media, and the importance of including the filter performance testing in future consideration of baghouse permitting, baghouse operation and maintenance (O&M) plans, quality assurance/quality control (QA/QC), and bag monitoring plans.

  2. Baghouse and cartridge dust collectors: A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, T.; Kelley, G. (Torit and Day, Minneapolis, MN (United States))

    1993-09-01

    Increased demands are being placed on air filtration systems. The particular application will determine whether a baghouse or cartridge type is best. Baghouse and cartridge dust collectors both have their place in modern air filtering systems. Baghouses have been in use much longer, but cartridge types offer significant advantages for particular applications. The task facing the site engineer is to match the requirements of the specific application with the inherent characteristics of the dust collector. This article presents basic information about both types of dust collectors that can help provide the best solution to that problem.

  3. Microcomputer programs for particulate control: section failure; baghouse; plume opacity prediction; and in-stack opacity calculator. Software

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, L.E.

    1985-09-01

    IBM-PC usable versions of several computer models useful in particulate control are provided. The models were originally written for the TRS-80 Model I-III series of microcomputers and have been translated to run on the IBM-PC. The documentation for the TRS-80 versions applies to the IBM-PC versions. The programs are written in FORTRAN and are provided in both source (FORTRAN) and executable form. Some small machine language routines are used to format the screen for data entry. These routines limit the programs to IBM-PC and close clones. The minimum hardware requirements are 256K IBM-PC or close clone, a monochrome monitor, and a disk drive. A printer is useful but not required. The following computer programs are provided in the four-disk package: (1) ESP section failure model, (2) GCA/EPA baghouse model, (3) Plume opacity prediction model, and (4) In-stack opacity calculator. All the models are documented in EPA report Microcomputer Programs for Particulate Control, EPA-600/8-85-025a (PB86-146529). The models provide useful tools for those involved in particulate control.

  4. Reducing pressure drop in a baghouse using flow distributors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [Tajen Institute of Technology, Ping-Tung Hsien (Taiwan). Dept. of Environmental Engineering and Health

    2001-10-01

    The pressure drop of ladder vanes in a baghouse could be reduced by decreasing the vane number and adjusting the inclined angle of the vane. Two types of flow distributors were utilized to test pressure drop caused by the structure of a baghouse. The pressure drops were measured by an inclined manometer under various filtration velocities. The purpose of this study is to understand the improvement effect of pressure drop saving on traditional ladder vanes. 14 refs., 6 figs.

  5. The Evolution of Improved Baghouse Filter Media as Observed in the Environmental Technology Verification Program

    Science.gov (United States)

    The U.S. EPA implemented the Environmental Technology Verification (ETV) program in 1995 to generate independent and credible data on the performance of innovative technologies that have the potential to improve protection of public health and the environment. Results are publicl...

  6. Selecting baghouse dust collectors

    Energy Technology Data Exchange (ETDEWEB)

    Moore, S.; Rubak, J.; Jolin, M. [Farr Co., El Segundo, CA (United States)]|[Farr Co., Laval, Quebec (Canada)

    1996-10-01

    Control of nuisance or process dusts generated within a plant is a vital concern with today`s growing emphasis on indoor air quality. In the past, many companies simply moved these contaminants away from workers and discharged them into the atmosphere. More stringent pollution control requirements now make this course of action unacceptable. Also, in some cases there is a need to recover high-value dusts, such as chemicals or precious metals. As a result, proper design and selection of a dust collection system are more critical than ever. There are two types of fabric filter dust collection systems commonly used today: baghouses and cartridges. Baghouses were the first collection systems with fabric media (in the form of long tubes, or bags) for removal of contaminants. The versatility of the baghouse--coupled with constant technological refinements--have made it a long-standing favorite among specifiers of pollution control equipment. In fact, baghouses account for more than 80% of all fabric filter dust collection systems in use today. Cartridge dust collectors use rigidly pleated filter elements instead of bags, making it possible to accommodate a large amount of filter surface area in a comparatively small package. Cartridge collectors also offer high efficiency and low pressure drop.

  7. Baghouse vs. precipator for dry scrubber systems - pilot study results

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, J.M.; Tonn, D.P.

    1981-01-01

    The first utility dry scrubber unit to be brought on line will be operating with baghouses for particulate emissions control, although precipitators have also been sold as part of dry sulfur removal (DSR) systems. There has been considerable discussion about the selection of particulate collection equipment for DSR systems and the choice between baghouse and precipitator is not always an obvious one, since overall system performnce must be reactor to supply the baghouse and precipator evaluated. The findings of an extensive testing program to investigate the performance characteristics of a pilot baghouse and pilot precipitator installed at 20 MW DSR demonstration plant are reported. Because an understanding of the interaction between the reactor and particulate collection is paramount to proper system design, both collection efficiencies and the contribution of the particulate collector to system sulfur dioxide (SO/sub 2/) removal are discussed. 6 refs.

  8. Baghouse with rotating sweep arm

    Energy Technology Data Exchange (ETDEWEB)

    Noland, R.D.

    1980-11-11

    A cleaning arm for a cylindrical baghouse pivoting centrally of the clean air plenum with a cam controlled valve to provide backflushing air to successive concentric rings of filter bags with each full revolution of the cleaning arm is described.

  9. Fabric filter technology for utility coal-fired power plants. Part I. Utility baghouse design and operation

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.C.; Smith, W.B.

    1984-01-01

    This is the first in a series of papers discussing the experience of electric utilities in applying baghouse technology for the collection of particulate matter at coal-fired electric power generating plants. The series presents new data obtained in research sponsored by the Electric Power Research Institute (EPRI) on reverse-gas and shake/deflate cleaned baghouses, and specifically addresses a number of unresolved issues in the design and operation of these units. The authors explain baghouse design and operation, and include discussions of utility boiler operation, fly ash characterization, and filtration mechanisms. 19 references.

  10. SNRB catalytic baghouse laboratory pilot testing

    Energy Technology Data Exchange (ETDEWEB)

    Kudlac, G.A.; Farthing, G.A. (Babcock and Wilcox, Alliance, Ohio (United States)) Szymanski, T. (Norton Co., Akron, OH (United States)); Corbett, R. (Dept. of Energy, Pittsburgh, PA (United States))

    1992-02-01

    The SOx-NOx-Rox Box{trademark} (SNRB) is an advanced air pollution process patented by Babcock and Wilcox (B and W) that provides for significantly reduced sulfur oxides (SO{sub x}), nitrogen oxides (NO{sub x}), and particulate emissions from coal-fired boilers. The process uses a high-temperature catalytic baghouse for integrating SO{sub x} reduction through injecting an alkali sorbent (such as hydrated lime or sodium bicarbonate), NO{sub x} removal through ammonia injection and selective catalytic reduction (SCR), and particulate collection. The advantages of the process include: compact integration of the emission control technologies into a single component; dry sorbent and by-product handling; and improved SCR catalyst life due to lowered SO{sub x} and particulate levels. The SNRB concept has been successfully demonstrated in a 1,500-ACFM pilot baghouse at B and W's Alliance (Ohio) Research Center. This paper describes the SNRB technology presents the SO{sub x}, NO{sub x}, and particulate removal performance results over a range of operating conditions for the laboratory pilot test program.

  11. Reducing pressure drop in a baghouse using flow distributors.

    Science.gov (United States)

    Chen, C J

    2001-10-01

    The pressure drop of ladder vanes in a baghouse could be reduced by decreasing the vane number and adjusting the inclined angle of the vane. Two types of flow distributors were utilized to test pressure drop caused by the structure of a baghouse. The pressure drops were measured by an inclined manometer under various filtration velocities. The purpose of this study is to understand the improvement effect of pressure drop saving for the traditional ladder vanes. Experimental results showed that the pressure drop of the Vane 3-1 configuration (flow distributor with three vanes perpendicular to the inlet flow) was higher than that of the Empty configuration (without flow distributors). The Vane 3-1 configuration could not reduce the pressure drop because of the barrier effect. By reducing the number and adjusting the angle of the vanes, the barrier effect was decreased, and the pressure drop of the Vane 2-1 configuration was much lower than that of the Vane 3-1 configuration. The largest difference in pressure drop between Vane 2-1 and Vane 3-1 was 1.702 cm w.g. at a filtration velocity of 4.17 cm/sec and, in terms of percentage, is 18.52% corresponding to a filtration velocity of 2.25 cm/sec. The improvement effect on the pressure drop saving for Vane 3-1 was significant.

  12. Alternatives for energy conservation in a baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Bakken, P.J.; Horney, F.A.

    1982-06-01

    This paper presents a comparison of alternate cases and how to achieve optimum energy consumption and economic benefits from baghouses or fabric filters for particulate control on coal fired boilers. Various components of baghouses are reviewed with an evaluation of fan efficiencies, duct routing, duct turning vanes, insulation, lagging, types of dampers and damper installations. Also discussed are cleaning cycle modes, ways to reduce baghouse pressure drop and dust reentrainment. A computer model to optimize the cleaning cycle is also discussed.

  13. Baghouse cleans flyash from boiler exhaust

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-01

    A large baghouse installation recently started up on the boilerhouse of the Avtex Fibers Inc. rayon plant in Front Royal, Virginia. The baghouse removes 99.7% of the flyash particulate from the combustion fumes of five coal-fired boilers. The boilers have a combined capacity of one million lb/h of steam. Emissions from the plant are well below EPA limitations.

  14. Summary of baghouse operation at the Nucla CFB Demonstration Plant

    Energy Technology Data Exchange (ETDEWEB)

    Heller, T.J. (Consolidated Edison Co. of New York, Nucla, CO (US)); Cushing, K.M. (Southern Research Inst., Birmingham, AL (United States)); Friedman, M.A. (Electric Power Research Inst., Palo Alto, CA (United States))

    1990-01-01

    This paper reports on baghouse performance. Air pollution control was upgraded at this plant by the addition of a twelve-compartment Research-Cottrell baghouse to supplement three existing, six-compartment, Wheelabrator- Frye baghouses that were installed in 1974. All four baghouses use shake/deflate cleaning. The baghouses have been in service since mid-1987 when the demonstration plant was placed in service.

  15. The role of pressure drop and flow redistribution on modeling mercury control using sorbent injection in baghouse filters.

    Science.gov (United States)

    Flora, Joseph R V; Hargis, Richard A; O'Dowd, William J; Karash, Andrew; Pennline, Henry W; Vidic, Radisav D

    2006-03-01

    A mathematical model based on simple cake filtration theory was coupled to a previously developed two-stage mathematical model for mercury (Hg) removal using powdered activated carbon injection upstream of a baghouse filter. Values of the average permeability of the filter cake and the filter resistance extracted from the model were 4.4 x 10(-13) m2 and 2.5 x 10(-4) m(-1), respectively. The flow is redistributed during partial cleaning of the filter, with flows higher across the newly cleaned filter section. The calculated average Hg removal efficiency from the baghouse is lower because of the high mass flux of Hg exiting the filter in the newly cleaned section. The model shows that calculated average Hg removal is affected by permeability, filter resistance, fraction of the baghouse cleaned, and cleaning interval.

  16. The role of pressure drop and flow redistribution on modeling mercury control using sorbent injection in baghouse filters

    Energy Technology Data Exchange (ETDEWEB)

    Joseph R.V. Flora; Richard A. Hargis; William J. O' Dowd; Andrew Karash; Henry W. Pennline; Radisav D. Vidic [University of South Carolina, Columbia, SC (United States). Department of Civil and Environmental Engineering

    2006-03-15

    A mathematical model based on simple cake filtration theory was coupled to a previously developed two-stage mathematical model for mercury (Hg) removal from coal combustion using powdered activated carbon injection upstream of a baghouse filter. Values of the average permeability of the filter cake and the filter resistance extracted from the model were 4.4 x 10{sup -13}m{sup 2} and 2.5 x 10{sup -4}m{sup -1}, respectively. The flow is redistributed during partial cleaning of the filter, with flows higher across the newly cleaned filter section. The calculated average Hg removal efficiency from the baghouse is lower because of the high mass flux of Hg exiting the filter in the newly cleaned section. The model shows that calculated average Hg removal is affected by permeability, filter resistance, fraction of the baghouse cleaned, and cleaning interval. 17 refs., 8 figs., 2 tabs.

  17. Some baghouse details relate to acfm, but

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, R.

    1981-01-01

    A large baghouse system being built for Houston Lighting and Power Co.'s Parish station illustrates some of the issues utilities face in boiler particulate control. Conventional baghouse specifications are not always applicable when larger sizes are needed or when a number of bags per compartment are used. Other differences related to system air-flow-oriented consideration are the design of outlet dampers, the size of inlet elbows, the choice of modular or structural design, land availability, foundations, compartment insulation, and ash-handling feeders. Baghouse details that are independent of air flow include suspension, entering gas velocity, flow modeling, hopper entry design, thimble length, and reverse-air cleaning. 4 figures. (DCK)

  18. Combining ESP and baghouse technology

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, B.; Ganatra, C.P.; Woolston, J. [W.L. Gore & Associates, Inc., Elkton, MD (United States)

    1994-12-31

    The authors present a progressive application in the field of air pollution control technology. The content of this paper should appeal to operators who must operate out-of-compliance electrostatic precipitators (ESPs), or to those who strive for optimal emission control. St. Lawrence Cement Company, a plant in Beauport Canada, has been in operation since 1955. Their two wet process kilns have utilized electrostatic precipitator (ESP) filters since inception. Since 1965, this company has strived to reduce energy consumption by using alternative waste fuel. This, combined with the increased demand of low alkali cement, took its toll on the ESPs, causing the equipment and its performance to deteriorate. Pressure from environmental agencies to lower outlet emissions forced the company to consider ESP modifications. After investigating several alternatives, the optimal modification was to combine the ESP with bag filters. In addition to being the best choice from a performance standpoint, it was also the least expensive. This modification also allowed a reduced alkali dust from the ESP hoppers to be recirculated to the kilns. The latter two-thirds of the ESP were converted to a baghouse, and optimal system performance was achieved by using high efficiency expanded polytetrafluoroethylene (ePTFE) membrane filter bags. Despite the high moisture, submicron particle size, and cohesive nature of the alkaline dust, very low pressure differentials and extremely low emissions were achieved. Most notably, this complex project was completed within nine months, from concept to commissioning. The plant was shut down for only six weeks during the entire retrofit process. This economically attractive idea was readily accepted by St. Lawrence Cement personnel and the permitting agencies. After the first successful kiln/ESP retrofit, the second kiln/ESP conversion was completed the following year.

  19. Working baghouse: design and operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, G.C.

    1980-01-01

    The installation of baghouses on coal-fired boilers at a power station in a paper mill in Pennsylvania is described. The decision making that preceded this event is described. After some initial problems, the bag life is expected to be 4 years. (DMC)

  20. Particulate-removal system upgraded with pulse-jet baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, T.

    1983-08-01

    A pulse-jet baghouse installed on a flue gas side-stream enhanced the performance of a small precipitator on Philadelphia Electric Co.'s Cromby unit 1 and enabled it to meet particulate standards. Pulse-jet baghouses have a gentle cleaning action that prolongs fabric life as well as improving particulate removal efficiency to the required 90%. Details of the baghouse design and operation are given. 2 figures. (DCK)

  1. Aerosol filtration - performance of filter media; Filtration des aerosols - performances des medias filtrants

    Energy Technology Data Exchange (ETDEWEB)

    Bemer, D.; Regnier, R. [Institut National de Recherche et de Securite (INRS), Dept. Ingenierie des Procedes, 75 - Paris (France); Calle, S.; Thomas, D.; Simon, X.; Appert-Collin, J.Ch. [Centre National de la Recherche Scientifique (CNRS), Lab. des Sciences du Genie Chimique de Nancy, 54 - Vandoeuvre-les-Nancy (France)

    2006-03-15

    Set up in 2000, the Laboratoire de Filtration des Aerosols in Nancy (LFA), associating research teams from INRS (Institut National de Recherche et de Securite and LSGC (Laboratoire des Sciences du Genie Chimique - CNRS), has been commissioned to provide expertise in the aerosol filtration field to both CRAM (Caisse Regionale de l'Assurance Maladie) prevention specialists and industrialists. Following a theoretical review of fibre medium filtration, this paper summarises the different actions undertaken by the LFA: filter performance during clogging with liquid and solid aerosols, modelling, pneumatic unclogging of baghouse dust collectors, influence of micro-leaks, etc. (authors)

  2. Recycle of baghouse product at Chatham CFB demonstration: Report

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The performance of the Chatham circulating fluidized bed unit was satisfactory and the design predictions were met in all areas with the exception of sulphur capture. To obtain 90 percent sulphur dioxide removal, a calcium-sulphur ratio of 2.5 is required compared to the predicted value of 1.35. A program was developed to recycle ash, collected in the baghouse, to the combustor to attempt to improve the utilization of the limestone. This test program included a sequence of recycle rates with a progressive increase in solids loading. System equilibrium was attempted at each stage prior to sampling the ash streams for analysis. A period of no ash recycle was also included after each sequence to allow comparison of results.

  3. Asbestos emissions from baghouse controlled sources.

    Science.gov (United States)

    Harwood, C F; Oestreich, D K; Siebert, P; Stockham, J D

    1975-08-01

    There is virtually no information published on the absolute efficiency of baghouses in reducing the emmisions of fine particles of asbestos. This lack of information is unfortunate because serious occupational health problems may result from the common practice of recirculating air to conserve energy. Emission testing has been conducted at five asbestos processing plants where the emissions are controlled by baghouses. The results showed that the mass removal efficiency frequently exceeded 99.00%. Membrane filter samples of the effluent were examined by optical and electron microscope. It was observed that despite the high mass efficiency, the number of fibers emitted, which were greater than 1.5 mum in length, was about 10(4)-10(5) fibers/m3, while the number of fibers less than 1.5 mum was 10(7)-10(8) fibers/m3. The significance of the size of the fibers in terms of probably health impact is briefly discussed.

  4. Evaluating baghouse systems for energy efficiency

    Energy Technology Data Exchange (ETDEWEB)

    1982-02-01

    Energy efficiency of pulse jet baghouses may be evaluated by the magnitude of the pressure drop across the unit and the amount of cleaning energy it takes to properly clean the filter bags. The higher the pressure drop, the higher the energy consumption. Hints are given on optimum pressure drop specification, and efficient pulse system design. Proper insulation of the collector and proper flow control devices also help to conserve energy.

  5. Flue gas conditioning for improved baghouse performance

    Energy Technology Data Exchange (ETDEWEB)

    Laudal, D.L.; Miller, S.J.

    1986-02-01

    Baghouse performance has been shown to be dependent on both the chemical and physical properties of the ash. Small amounts of ammonia and sulfur trioxide were added to the flue gas as conditioning agents to modify ash characteristics and reduce fine particulate emissions from a pilot-scale coal combustion/baghouse system. Tests were made with three western low-rank coals which produce difficult to collect fly ash. Total particulate emissions over several cleaning cycles were substantially reduced and fine particulate emissions were reduced up to four orders of magnitude between the cycles. With conditioning baghouse pressure drop increased at a slower rate and reached a lower operating pressure drop after several cleaning cycles. Ash samples were analyzed to determine physical and chemical changes due to ammonia and sulfur trioxide addition. Several ammonia-sulfur compounds were found indicating a complex chemical mechanism. Changes in the fly ash particle size distribution and bulk ash cohesiveness may help explain the physical mechanism by which both pressure drop and particulate emissions are reduced. 14 refs., 7 figs., 4 tab.s

  6. Determination of baghouse performance from coal and ash properties: part

    Energy Technology Data Exchange (ETDEWEB)

    Bush, P.V.; Snyder, T.R.; Chang, R.L.

    1989-02-01

    Baghouse performance at utility coal-fired power plants is determined by baghouse design, operating procedures, and the characteristics of the ash that is collected as a dustcake on the fabric filter. The Electric Power Research Institute has conducted laboratory research to identify the fundamental properties of dustcake ash that influence baghouse performance. A database was assembled including measured characteristics of dustcake ash and data describing operating parameters and performance of full-scale and pilot-scale baghouses. Semi-empirical models were developed that describe the effects of particle morphology, particle size, ash cohesivity and ash chemistry on filtering pressure drop and particulate emissions. Cohesivity was identified as the primary ash characteristic affecting baghouse performance. Predictions of performance can be based on physical or chemical characterizations of the ash to be filtered.

  7. Impact of fly ash composition upon shaker baghouse efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sears, R.; Miller, S.J.

    1984-03-01

    Many parameters can have major effects on fabric filter performance. The most extensively published research in fabric filtration has concentrated on baghouse related parameters such as fabric type, cleaning mode, cleaning cycle, and air-to-cloth ratio. To a lesser extent studies have considered ash characteristics such as particle size distribution and specific filter resistance coefficient, K/sub 2/. Little research has been reported relating coal or ash properties to fabric filter performance. This paper deals with penetration from a shaker chamber with one specific fabric. The independent variable is major element concentration in fly ash. Air-to-cloth ratios varied only because combustion conditions control flue gas volumes. Results indicate that first, fabric filter performance is indeed coal specific with large differences in removal efficiency with different ashes. Second, the results reveal a definite inverse correlation between penetration and sodium concentration in the fly ash for the fabric and cleaning configuration considered. For the ashes that demonstrate poor performance in tests, careful selection of the correct fabric together with a conservative air-to-cloth ratio and the optimum cleaning cycle may all be necessary in order to maintain an adequate residual dust cake and bring the efficiency up to an acceptable level. Heavy dust cake formation may be necessary to achieve high efficiencies with these coals. Residual dust cake for the coals that showed high efficiencies in these tests may not be important, since North Dakota lignites give excellent efficiencies immediately after starting with new bags. Apparently the latter ashes build up on the woven fabric layer in such a way that openings in the weave and pinholes are immediately bridged over. These coals may then be candidates for high ratio filtration with conventional, economical woven fabric. 28 references, 10 figures, 4 tables.

  8. Fractional efficiency of a utility boiler baghouse. Nucla generating plant. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bradway, R.M.; Cass, R.W.

    1975-08-01

    The report gives results of an extensive testing program performed on a fabric filter baghouse operating on a small coal-fired utility boiler. Total mass loadings were obtained by sampling upstream and downstream using Method 5 techniques; particulate size distributions were obtained with instack impactors. A condensation nuclei counter/diffusion denuder system was also used for submicrometer sizing analysis, but the instrumentation was found to be difficult to work with and very sensitive to the static pressure of the sample stream. The results of 22 tests indicated a mean mass efficiency of 99.84 percent. Eleven tests were run at normal baghouse operating conditions and eleven were run at abnormal operating conditions. Statistical analyses show no significant influence of the abnormal operating conditions on particulate penetration. (GRA)

  9. Coal-preparation baghouse protects against explosion damage

    Energy Technology Data Exchange (ETDEWEB)

    1983-09-01

    Improvements in baghouse containment technology are reducing the risks when air and coal dust mixtures ignite and cause secondary explosions that were formerly vented. The cement industry was quick to adopt the new technology that resembles a circular pressure vessel able to withstand a 50-psi internal pressure and contain secondary explosions. Steps to minimize primary explosions include new standards for baghouse design and construction to eliminate components that cause sparks, electrical grounding, continuous dust removal, high air-to-cloth ratios, and pulse jet cleaning. Other considerations involving baghouse location, maintenance access, fire suppression, and rotary valve sizing can also reduce explosion risks. (DCK)

  10. Sorbent and ammonia injection at economizer temperatures upstream of a high-temperature baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Chu, P.; Downs, B.; Holmes, B. (Babcock and Wilcox Co., Alliance, OH (USA))

    1990-08-01

    The current technology of choice - world-wide - for post-combustion NO{sub x} control is selective catalytic reduction (SCR) with ammonia. The application of SCR to coal-fired units has proven to be somewhat more difficult than its application to natural gas and oil-fired units due to SO{sub 2} poisoning of the catalyst, catalytic oxidation of SO{sub 2} to SO{sub 3}, and erosion and fouling of the catalyst by fly ash. These problems could be potentially diminished if SO{sub 2} and particulate removal systems were placed upstream of the SCR reactor. However, this is not easily accomplished since SCR systems operate best in the temperature range of 600{degree}F-800{degree}F (315{degree}C-425{degree}C). Several SCR installations in Europe employ conventional flue gas desulfurization (FGD) and particulate control upstream of flue gas reheat and SCR. However, the flue gas reheat typically imposes a 1%-2% energy penalty. Several recent technical developments now offer a technology whereby these limitations of SCR for coal applications can be alleviated. These technical developments are in the areas of high temperature filtration, improved SCR catalysts, and advances in sorbent injection. These advances have been incorporated into a patented process known as the SO{sub x}-NO{sub x}-Rox Box (SNRB) process. Briefly, this process consists of a hot baghouse employing woven ceramic fabric bags, a zeolite SCR catalyst incorporated into the baghouse, and the injection of either calcium- or sodium-based sorbent upstream of the baghouse. This paper deals with the status and development of the SNRB process, including some results from recently completed pilot-plant tests performed under a contract with the Ohio Coal Development Office (OCDO).

  11. Method for baghouse brown plume pollution control

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, R.G.

    1990-03-13

    This patent describes an SO{sub x}/NO{sub x} air pollution control process employing a baghouse to simultaneously control particulate emissions. It comprises: introducing a sodium-based reagent into a stream of flue gas containing SO{sub x} and NO{sub x}; introducing urea as an additive into the flue gases; maintaining the reagent and the additive in contact with the flue gas to react the reagent with some of the SO{sub x} and NO{sub x} thereby reducing the concentration of the SO{sub x} and NO{sub x} in the flue gas; the additive, as compared to use of the reagent without the additive, increasing the percent SO{sub x} removal and the percent NO{sub x} removal by the reagent while suppressing conversion of NO to NO{sub 2} by the reagent to below about the visible brown plume threshold; and collecting the reacted reagent and additive in a baghouse.

  12. Cool baghouse spaces for on-line M and R

    Energy Technology Data Exchange (ETDEWEB)

    McGraw, M.G.

    1979-07-15

    The design, installation, operation, maintenance and repair experience since 1973 of baghouses at the Pennsylvania Power and Light Co. and the Southwest Public Service Co. (SPS) in Amarillo, Texas are reviewed. The particulate removal efficiency of these fiber-glass fabric filter baghouses has averaged from 99.91 to 99.94%, bag failure has been minimal, cleaning by reversing air flow through the bags has proved effective and fast, and these units permit on-line maintenance as compared with the shut-down maintenance requirement for other stack pollution control equipment. The largest baghouse in operation has 28 compartments with 204 bags each at a 350 MW coal-fired SPS plant. Baghouse installation at a 543-MW plant is planned, and other utilities are increasingly using this pollution control method. (LCL)

  13. An analysis of baghouse performance in the Riverside Dry Scrubber

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.J.; Skinner, M.F.

    1982-12-01

    The results of baghouse and fabric testing during 1981 at the Riverside Dry FGD Demonstration Facility are presented in this paper. Operating parameters and baghouse performance data are summarized. The results of the fabric evaluation test are discussed. Pressure drop measurements are reported and pressure drop predictions for various fabric filters based on the experimental data are compared. Measurements reported in the paper cover operation with Colstrip coal, Illinois coal, and Sarpy Creek coal.

  14. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    Energy Technology Data Exchange (ETDEWEB)

    Zaromb, S.; Lawson, D.B.

    1994-02-15

    A process for recovering zinc-rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered by distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10 C, separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream. 1 figure.

  15. Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

    Science.gov (United States)

    Zaromb, Solomon; Lawson, Daniel B.

    1994-01-01

    A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

  16. Iron and steel foundries manual emissions testing of cupola baghouse at Waupaca Foundry in Tell City, Indiana: Volume 1 -- Report text and appendices A and B. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Meadows, F.; Scheffel, D.F.

    1999-06-01

    The US Environmental Protection Agency (EPA) Emission Standards Division (ESD) is investigating iron and steel foundries to identify and quantify hazardous air pollutants (HAPs) emitted from cupolas; electric arc furnaces; and pouring, cooling and shakedown operations of sand mold casting processes. The Waupaca Foundry, located in Tell City, Indiana, uses a baghouse and was the subject of this test program. Testing at the Waupaca Foundry was conducted by two EMAD contractors to address the following ESD requirements: (1) characterize HAP emissions from cupolas that are controlled by baghouses; (2) characterize uncontrolled HAP emissions from pouring, cooling, and shakeout (PCS) processes; (3) determine baghouse performance in controlling HAP emissions from cupolas; and (4) identify surrogates for estimating HAP emissions from the subject foundry processes.

  17. Improving baghouse performance at the Monticello Generating Station

    Energy Technology Data Exchange (ETDEWEB)

    Felix, L.G.; Merritt, R.L.; Duncan, K.

    1986-09-01

    At the Monticello station, operated by the Texas Utilities Generating Company, lignite coal fuels each of the three units. Units 1 and 2 are identical 575-MW boilers, each of which discharges its effluent to a 36-compartment shake/deflate cleaned baghouse paralleled with four electrostatic precipitators (ESP). The baghouses were designed to clean 80 percent of the flue gas. Since startup, these baghouses have regularly experienced pressure drops caused by ash bleeding through the bags after compartment cleanings. Because of higher-than-expected pressure drop, the baghouses receive only about 45-50 percent of the flue gas. Analysis has shown the Monticello lignite ash significantly differs from most other coal ashes. Testing has shown that the Monticello ash is not filtered effectively by many standard bag materials. However, this testing indicates that there are fabrics that show promise of eliminating the ash bleedthrough with little pressure drop penalty. Testing has also shown that injection of low concentrations (10-15 ppm) of ammonia (NH/sub 3/) into the flue gas significantly decreases ash bleedthrough, so that with NH/sub 3/ injection, standard bag materials may perform adequately. Currently, full-compartment testing of four fabrics, with and without NH/sub 3/ injection, is under way at the Unit 1 baghouse. The research conducted at the Monticello stations is reviewed in this paper and the encouraging results from the full-compartment tests are presented. 12 refs.

  18. Modifications improve efficiency of hogged-fuel-fired boiler baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Bundy, R.P.; Plunkett, T.P.

    1980-01-01

    Baghouses are apparently the most efficient air pollution control devices for hogged-fuel-fired boilers. Although operating experience in this field is limited, new second-generation units are now operating which incorporate certain design changes (described), for controlling fire dangers and optimizing both bag life and maintenance. Guidelines are given for the selection of the proper bag fabric, and methods are described for avoiding abrasion of both the bags and the bag support system. Baghouse maintenance procedures are described, and potential fire hazards and fire protection systems are discussed.

  19. Diseño de filtros de talegas Baghouses desing

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Echeverri Londoño

    2008-01-01

    Full Text Available Este artículo presenta los criterios generales para el diseño de filtros de talegas para el control de partículas.This article shows general criteria for designing baghouses for particle control.

  20. Effect of bag failure on baghouse outlet loading

    Energy Technology Data Exchange (ETDEWEB)

    Theodore, L.; Reynolds, J.

    1979-08-01

    Bag failure is one of the more serious problems encountered in filter baghouse operation. Equations describing changes in outlet loading resulting from the sudden rupture of one or more bags are developed. Calculated results from the equations are given in a chart that can be used to quickly obtain a numerical value for a revised outlet loading. (1 graph)

  1. Proceedings: Workshop on pulse-jet baghouse technology

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.; Cushing, K.M.; Wilson, R.R.

    1989-01-01

    The EPRI Pulse-Jet Technology Workshop held in Atlanta, Georgia on May 19--20, 1988 assessed the potential of pulse jets for utility applications, discussed key unresolved issues, and identified important development activities. Forty-two representatives from fiber, fabric, bag and baghouse vendors, research groups, consultants and six utilities attended. The workshop was divided into three sessions. The first session consisted of presentations summarizing: (1) the state-of-the-art in pulse-jet baghouse technology; (2) pulse-jet user experience; and (3) the technical economic feasibility of using pulse jets. In the second session, a panel representing different segments of this technology discussed the key issues in adapting pulse-jet baghouses to US utility applications. The final session contained reports to the workshop attendees from each of the four working groups formed to discuss: (1) general pulse-jet baghouse design considerations; (2) filter fabric design, testing, characterization and failure analysis; (3) pilot facility test design and testing requirements; and (4) technical/economic feasibility and critical issues in the application of pulse jets. In the opinion of the workshop participants, initial applications would probably be retrofits into the casing of existing electrostatic precipitators (ESP) or at stations with retrofit AFBC or dry/semi-dry SO/sub 2/ control processes. 18 figs., 18 tabs.

  2. Pulse-jet baghouse performance improvement with flue gas conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.; Laudal, D.L.

    1992-10-01

    A pilot study was conducted at the Energy and Environmental Research Center (EERC) at the University of North Dakota to evaluate the effectiveness of flue gas conditioning in reducing tube sheet pressure drop and fine particulate emissions from a pulse-jet fabric filter. The project was jointly funded by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), and the Canadian Electrical Association (CEA). The work was completed with EERC facilities consisting of a pulverized coal-fired combustor and pilot baghouse. Full-scale pulse-jet bags were employed under conditions similar to large-scale baghouses. The investigation included baseline tests and tests in which ammonia and SO{sub 3} were, injected upstream of the baghouse to determine the effect of conditioning on baghouse performance. The primary independent variables included coal type, conditioning agent concentrations, air-to-cloth (A/C) ratio, and fabric type. The main dependent variables were particulate emissions, bagbouse pressure drop, and cohesive properties of the fly ash. Results demonstrated significant benefits of using conditioning with a pulse-jet baghouse, including a substantial reduction in particulate emissions and a substantial reduction in pressure drop (or the ability to operate at a higher A/C ratio without increasing pressure drop or bag-cleaning frequency). The improvements in fabric filter performance correlate strongly with a shift in the tensile strength and with increases in the aerated and packed porosity of the fly ash. Conditioning appears to be applicable to a wide range of coals and fabrics. Applications for this technology are where there is a need to reduce pressure drop and/or particulate emissions in existing bagbouses, to reduce fine-particle air toxic emissions which may be required in the future, and for new bagbouse installations to allow operation at a higher A/C ratio while providing an ultrahigh fine-particle collection efficiency.

  3. Pulse-jet baghouse performance improvement with flue gas conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.; Laudal, D.L.

    1992-10-01

    A pilot study was conducted at the Energy and Environmental Research Center (EERC) at the University of North Dakota to evaluate the effectiveness of flue gas conditioning in reducing tube sheet pressure drop and fine particulate emissions from a pulse-jet fabric filter. The project was jointly funded by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), and the Canadian Electrical Association (CEA). The work was completed with EERC facilities consisting of a pulverized coal-fired combustor and pilot baghouse. Full-scale pulse-jet bags were employed under conditions similar to large-scale baghouses. The investigation included baseline tests and tests in which ammonia and SO[sub 3] were, injected upstream of the baghouse to determine the effect of conditioning on baghouse performance. The primary independent variables included coal type, conditioning agent concentrations, air-to-cloth (A/C) ratio, and fabric type. The main dependent variables were particulate emissions, bagbouse pressure drop, and cohesive properties of the fly ash. Results demonstrated significant benefits of using conditioning with a pulse-jet baghouse, including a substantial reduction in particulate emissions and a substantial reduction in pressure drop (or the ability to operate at a higher A/C ratio without increasing pressure drop or bag-cleaning frequency). The improvements in fabric filter performance correlate strongly with a shift in the tensile strength and with increases in the aerated and packed porosity of the fly ash. Conditioning appears to be applicable to a wide range of coals and fabrics. Applications for this technology are where there is a need to reduce pressure drop and/or particulate emissions in existing bagbouses, to reduce fine-particle air toxic emissions which may be required in the future, and for new bagbouse installations to allow operation at a higher A/C ratio while providing an ultrahigh fine-particle collection efficiency.

  4. Development of guidelines for optimum baghouse fluid-dynamic-system design. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Eskinazi, D.; Gilbert, G.B.

    1982-06-01

    In recent years, the utility industry has turned to fabric filters as an alternative technology to electrostatic precipitators for particulate emission control from pulverized coal-fired power plants. One aspect of baghouse technology which appears to be of major importance in minimizing the size, cost, and operating pressure drop is the development of ductwork and compartment designs which achieve uniform gas and dust flow distribution to individual compartments and bags within a compartment. The objective of this project was to perform an experimental modeling program to develop design guidelines for optimizing the fluid mechanic performance of baghouses. Tasks included formulation of the appropriate modeling techniques for analysis of the flow of dust-laden gas through the collector system and extensive experimental analysis of fabric filter duct system design. A matrix of geometric configurations and operating conditions was experimentally investigated to establish the characteristics of an optimum system, to identify the level of fluid mechanic sophistication in current designs, and to experimentally develop new ideas and improved designs. Experimental results indicate that the design of the inlet and outlet manifolds, hopper entrance, hopper region below the tubesheet, and the compartment outlet have not been given sufficient attention. Unsteady flow patterns, poor velocity profiles, recirculation zones, and excessive pressure losses may be associated with these regions. It is evident from the results presented here that the fluid mechanic design of fabric filter systems can be improved significantly.

  5. Using fume silica as heavy metals' stabilizer for high alkali and porous MSWI baghouse ash.

    Science.gov (United States)

    Huang, Wu-Jang; Huang, Hung-Shao

    2008-03-21

    In this study, we have proved that heavy metals in high porous and alkali baghouse ash could be fixed effectively by fume silica powder alone, or with the incorporation of colloidal aluminum oxide (CAO). The optimum amount is about 100g of fume silica per kilogram of baghouse ash. Results have indicated that fume silica has a better fixation efficiency of lead in high porous baghouse ash. In addition, the reaction mechanism of fume silica is also discussed.

  6. Baghouse heat exchanger saves fuel, protects equipment, warms workers

    Energy Technology Data Exchange (ETDEWEB)

    Krout, B.; Kilheffer, J.

    1984-03-01

    A heat exchanger system designed to cool 900/sup 0/F exhaust air from a rotary kiln has also proven that it can provide large annual fuel savings, protect equipment from freezing and increase employee comfort. The system uses two plate-type heat exchangers and a fiber glass baghouse utilizing reverse air cleaning. The heat exchangers were designed to lower the kiln exhaust temperature from 900/sup 0/F to 500/sup 0/F prior to entering the baghouse. A bleed-in damper in the ductwork ensures that gases entering the heat exchanger do not exceed 900/sup 0/F. The units have a heat-transfer surface of 14,786 ft/sup 2/, design inlet volume of 120,000 ACFM and design outlet volume of 84,000 ACFM. The heat exchanger has a built-in cleaning mechanism which operates on a timer and limits the build-up of deposits on the heat exchanger surfaces.

  7. Baghouse installation on pulverized coal-fired boilers burning low-sulfur eastern coals at Michigan State University

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, P.A.; Heil, T.J.; Dimitry, P.

    1980-01-01

    This paper discusses the study made to determine the suitability of installing baghouses for the power plant boilers. It outlines the basic design criteria of the baghouse filter system, lists special design features incorporated in the baghouses, and covers startup and operating experiences.

  8. Baghouse performance and ash characterization at the Arapahoe Power Station

    Energy Technology Data Exchange (ETDEWEB)

    Dahlin, R.S.; Sears, D.R.; Green, G.P.

    1982-01-01

    This paper presents the results of a field test conducted in March 1981, on the Unit 3 baghouse of the Arapahoe Station of the Public Service Company of Colorado. The unit was burning a subbituminous coal from Routt County, Colorado, and was retrofitted with a baghouse in 1979. Baghouse performance was found to be excellent with an overall mass efficiency of 99.98%. The estimated cumulative collection efficiency of all particles smaller than two microns was 99.92%. The Grand Forks Energy Technology Center of the US Department of Energy, through its contractor Southern Research Institute, is conducting a series of field tests to study the characteristics and control of fly ash from the combustion of low-rank Western coals. Emphasis is being placed on two types of coal: Western subbituminous coal and Texas lignite. The overall objective of the project is to provide data that will be useful in evaluating particulate control technologies for these coals. To date, two field tests have been performed. The first field test, the subject of this paper, was conducted in march 1981, at Unit 3 of the Arapahoe Power Station of the Public Service Company of Colorado. The unit, retrofitted with a baghouse that was placed in service in May 1979, was burning a low-sulfur subbituminous coal from Routt County, Colorado. The second field test, which was jointly sponsored by DOE and EPRI, was completed in May 1982 at the San Miguel Station of the San Miguel Electric Cooperative located between San Antonio and Corpus Christi, Texas. Results of the San Miguel test will be reported elsewhere.

  9. Spray dryer/baghouse flue gas desulfurization (FGD) evaluation for high-sulfur utility applications

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, T.A.; Threet, G.E. Jr.; Humphries, L.R.; Robards, R.F.; Runyan, R.A.

    1985-01-01

    The Tennessee Valley Authority (TVA) initiated a program in 1983 to evaluate two pilot spray dryer/baghouse FGD systems. The main objective of this testing was to determine if the new type of FGD system, which was being commercialized on low-sulfur coal applications, was capable of treating flue gas from high-sulfur coal-fired utility boilers. Variables which were evaluated include lime stoichiometry, approach-to-saturation temperature, recycle rate, flue gas residence time in the spray dryer, atomizer speed, inlet flue gas temperature, and inlet SO/sub 2/ concentration. As expected, the SO/sub 2/ removal efficiency is a strong function of lime stoichiometry and approach-to-saturation temperature.

  10. The potential of pulse-jet baghouses for utility boilers part 3: Comparative economics of pulse-jet baghouse, precipitators and reverse-gas baghouses

    Energy Technology Data Exchange (ETDEWEB)

    Sloat, D.G.; Gaikwad, R.P. (Sargent Lundy, Chicago, IL (United States)); Chang, R.L. (Electric Power Research Inst., Palo Alto, CA (United States))

    1993-01-01

    Pulse-jet fabric filters (PJFFs) are widely used in US industrial applications, and in both utility and industrial boilers abroad. Their smaller size and reduced cost relative to more conventional baghouses make PJFFs an attractive particulate control option for utility boilers. This article which is the third in a three-part series, compares the cost of PJFFs with electrostatic precipitators (ESPs) and reverse-gas baghouses (RGBs). This article presents the capital, operating and maintenance (O M), and levelized costs for ESPs, RGBs and PJFFs. The particulate control equipment design and pricing are supplied by manufacturers of the control equipment. A comparison of costs for a base case 250-MW boiler indicates that the PJFF capital cost is 22 percent lower than the cost of an ESP with 400 SCA and 12-inch plate spacing; in addition the PJFF is 35 percent lower than the cost of an RGB. The levelized cost for a PJFF is about equal to the cost of the ESP but 14 percent lower than the cost of the RGB. Overall, the attractiveness of a PJFF versus an ESP depends on the coal type and the outlet emissions limit required. PJFF is favored when low-sulfur coal is fired due to the high-resistivity fly ash. Also, PJFF is favored as more stringent outlet emission rates are required. 11 refs., 10 figs., 6 tabs.

  11. What baghouse is best for your industrial boiler: reverse air or pulse jet

    Energy Technology Data Exchange (ETDEWEB)

    Berst, A.H.

    1981-01-01

    In summary, the pulse jet has great advantage for side stream application and the smaller boiler sizes. For larger systems the reverse air baghouse should be used. Whatever system is selected, the customer should look carefully at the details of construction and the baghouse manufacturer's experience. The customer should also consider the type of coal to be burned and the possibility of change in coal because of its effect on the baghouse pressure drop. There is a marked difference between Western and Eastern coal fly ash. The Western coal will usually cause a higher pressure drop.

  12. Effect of bag failure on baghouse outlet loading

    Energy Technology Data Exchange (ETDEWEB)

    Theodore, L.; Reynolds, J.

    1979-08-01

    One of the most important considerations in baghouse operation is the effect of bag failure on outlet loading. This information would be of use to equipment manufacturers, users, and regulatory officials. Unfortunately, little information is available in the literature on this aspect of baghouse performance. Equations describing changes in outlet loading resulting from the sudden rupture of one or more bags are developed from first principles. Calculated result from these equations are presented in the form of a chart which can very quickly and simply be used to obtain a numerical value for a revised outlet loading resulting from bag failure(s) for a variety of system conditions. Due to an assumption made in the derivation, the new outlet loading thus obtained represents the maximum increase (worst case conditions) to be expected from the rupture of one or more bags. The following variables are included in the analysis: inlet loading, outlet loading (prior to bag failure), number of bag failures, bag diameter, system pressure drop; and gas temperature.

  13. Economic evaluation of precipitators and baghouse for typical power plant burning low-sulfur coal

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, M.E.

    1978-01-01

    The economics of four basic flyash collection systems, i.e., hot precipitator system, cold precipitator system, cold precipitator gas conditioned system, and baghouse system, for power plants burning low-sulfur coal are considered. (LCL)

  14. Results of a baghouse operation and maintenance survey on industry and utility coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.; Kreidenweis, S.; Theodore, L.

    1982-06-01

    This paper presents results of a baghouse operation and maintenance survey on industry and utility coal-fired boilers. The survey consisted of a comprehensive questionnaire suitable to statistical interpretation and computer analysis.

  15. Startup and operating experience shows how to get the most out of your baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Pruce, L.M.

    1981-03-01

    A recent conference in the USA addressed itself to the problems involved with the efficient running of baghouse dust collecting systems. This article summarizes the main points brought out during the conference.

  16. Development process for the stabilization of incinerator bottom ash and sizing baghouse dust material

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, L.F.; Boehmer, A.M.

    1987-04-01

    EG G Idaho Inc. has initiated a program to develop safe, efficient, cost-effective treatment methods for the stabilization and subsequent disposal of some of the hazardous and mixed wastes generated at the Idaho National Engineering Laboratory (INEL). Lab-scale testing has shown that Extraction Procedure (EP) toxic wastes can be successfully stabilized by solidification, using various binders to produce nontoxic, stable waste forms for safe, long-term disposal. The purpose of this report is to present the results of drum-scale testing of WERF incinerator bottom ash and WERF sizing baghouse dust. The drum-scale test program was conducted to determine if a production procedure that would produce a waste form which was suitable for disposal as a low-level radioactive waste could be developed. The use of 71-gallon square drums for solidification processing were also evaluated. During the test program, eleven drums of ash material were solidified. All of the samples from all of the drums passed the EPA leach test criteria. Although there is a distinct weight addition associated with the solidification process, there is no relative volume increase. 4 refs., 6 figs., 8 tabs.

  17. Optimization of material, design, and operational parameters associated with full-scale 400,000-acfm fabic filter baghouse on the City of Colorado Springs' Martin Drake Generating Unit No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Ostop, R.L. (Department of Public Utilities, Colorado Springs, CO); Thaxton, L.A.

    1978-01-01

    A program for determining the optimum design, construction, and operation of a fabric filter baghouse for control flyash emissions from a Colorado power plant fueled with low-sulfur coal is described. The primary purposes of this program were to show that fabric filter system can be designed on scientific principles rather than rule-of-thumb methods and that the operation of such a system can be optimized for greatest cost effectiveness. (LCL)

  18. Liquid filtration simulation

    Energy Technology Data Exchange (ETDEWEB)

    Corey, I.; Bergman, W.

    1996-06-01

    We have a developed a computer code that simulates 3-D filtration of suspended particles in fluids in realistic filter structures. This code, being the most advanced filtration simulation package developed to date, provides LLNL and DOE with new capabilities to address problems in cleaning liquid wastes, medical fluid cleaning, and recycling liquids. The code is an integrated system of commercially available and LLNL-developed software; the most critical are the computational fluid dynamics (CFD) solver and the particle transport program. For the CFD solver, we used a commercial package based on Navier-Stokes equations and a LLNL-developed package based on Boltzman-lattice gas equations. For the particle transport program, we developed a cod based on the 3-D Langevin equation of motion and the DLVO theory of electrical interactions. A number of additional supporting packages were purchased or developed to integrate the simulation tasks and to provide visualization output.

  19. Determination of baghouse performance from coal and ash properties: part II

    Energy Technology Data Exchange (ETDEWEB)

    Vann Bush, P.; Snyder, T.R.; Chang, R.L.

    1989-03-01

    Baghouse performance at utility coal-fired power plants is determined by baghouse design, operating procedures, and the characteristics of the ash that is collected as a dustcake on the fabric filter. The Electric Power Research Institute has conducted laboratory research to identify the fundamental variables that influence baghouse performance. A database was assembled including measured characteristics of coal and dustcake ash, and data describing operating parameters and performance of full-scale and pilot-scale baghouses. Predictions of performance can be based on physical characteristics of the ash to be filtered (discussed in Part I of this article), as well as chemical characterizations of the ash, or empirical correlations with the alkali content of the source coal. The effects of design and operational variables can be included in these predictions. Baghouse performance can be optimized by exercising proper operating practices and by selecting a filtering fabric and cleaning method matched to the cohesivity of the ash to be collected. 13 refs., 13 figs., 2 tabs.

  20. Effect of flow distributors on uniformity of velocity profile in a baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Chi-Jen Chen; Man-Ting Cheng [Tajen Institute of Technology, Ping-Tung Hsien (Taiwan). Department of Environmental Engineering and Science

    2005-07-01

    In recent years, baghouses have been used as an alternative technology for particulate emission control from pulverized-coal-fired power plants. One of the more significant issues is to improve poor gas distribution that causes bag failures in baghouse operation. Bag failures during operation are almost impossible to prevent, but proper flow design can help in their prevention. This study investigated vertical velocity profiles below the bags in a baghouse (the hopper region) to determine whether flow could be improved with the installation of flow distributors in the hopper region. Three types of flow distributors were used to improve flow distribution and were compared with the original baghouse without flow distributors. Velocity profiles were measured by a hot-wire anemometer at an inlet velocity of 18 m/sec. Uniformity of flow distribution was calculated by the uniformity value U for the velocity profile of each flow distributor. Experimental results showed that the velocity profile of the empty configuration (without flow distributors) was poor because the uniformity value was 2.048. The uniformity values of type 1 (flow distributor with three vertical vanes), type 2 (flow distributor with one vertical and one inclined vane), and type 3 (flow distributor with two inclined vanes) configurations were reduced to 1.051, 0.617, and 0.526, respectively. These results indicate that the flow distributors designed in this study made significant improvements in the velocity profile of a baghouse, with the type 3 configuration having the best performance. 11 refs., 10 figs.

  1. Baghouse efficiency on a multiple-hearth incinerator burning sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Adams, R.C.; Keller, L.E.; Robb, E.V.; Vancil, M.C.; Farrell, J.B.

    1989-04-01

    A pilot-scale fabric filter (baghouse) was evaluated for its removal performance for 23 metals and for sulfur as well as for total particles when fitted to a multiple-hearth incinerator burning sewage sludge. The small-scale baghouse was installed to take a slipstream of about 3% of the total incinerator emissions. Particle size fractions were collected from the gas streams entering and leaving the baghouse. Each particle-size fraction was analyzed for the 24 elemental species and baghouse performance was evaluated for overall removal efficiency, size-fraction removal efficiency, and for selective removal of specific metals. Total concentrations of each element in the controlled emission stream was determined as well as the proportionate concentrations of species in the solid and volatile states. Concentrations of each metal in the emission stream was compared with the concentration in a sludge residue. To obtain comparisons of baghouse performance with a more typical emission control device, the performance of the incinerator's full-scale wet scrubber was also evaluated.

  2. Effect of flow distributors on uniformity of velocity profile in a baghouse.

    Science.gov (United States)

    Chen, Chi-Jen; Cheng, Man-Ting

    2005-07-01

    In recent years, the utility industry has turned to baghouses as an alternative technology for particulate emission control from pulverized-coal-fired power plants. One of the more significant issues is to improve poor gas distribution that causes bag failures in baghouse operation. Bag failures during operation are almost impossible to prevent, but proper flow design can help in their prevention. This study investigated vertical velocity profiles below the bags in a baghouse (the hopper region) to determine whether flow could be improved with the installation of flow distributors in the hopper region. Three types of flow distributors were used to improve flow distribution and were compared with the original baghouse without flow distributors. Velocity profiles were measured by a hot-wire anemometer at an inlet velocity of 18 m/sec. Uniformity of flow distribution was calculated by the uniformity value U for the velocity profile of each flow distributor. Experimental results showed that the velocity profile of the empty configuration (without flow distributors) was poor because the uniformity value was 2.048. The uniformity values of type 1 (flow distributor with three vertical vanes), type 2 (flow distributor with one vertical and one inclined vane), and type 3 (flow distributor with two inclined vanes) configurations were reduced to 1.051, 0.617, and 0.526, respectively. These results indicate that the flow distributors designed in this study made significant improvements in the velocity profile of a baghouse, with the type 3 configuration having the best performance.

  3. GSPEL - Air Filtration Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Evaluation capabilities for air filtration devicesThe Air Filtration Lab provides testing of air filtration devices to demonstrate and validate new or legacy system...

  4. Precipitator or baghouse - evaluation to retrofit for no visible emissions on low sulfur coal

    Energy Technology Data Exchange (ETDEWEB)

    Gosnell, R.R.; Kusterer, J.N.

    1986-01-01

    In June 1982 a comprehensive engineering study was undertaken at the Baltimore Gas and Electric Company's H.A Wagner 3 plant as it needed to conform to the State of Maryland's emissions requirements. The paper considers whether to modify and renovate the existing electrostatic precipitators or to retrofit with a baghouse or another electrostatic precipitator. Topics are background, engineering data, engineering approach, renovation of existing precipitator including causes of performance deficiency, structural evaluation, recommendation for performance improvement and performance results, retrofit analysis, including retrofit options, comparative analysis of retrofit options, initial conclusions, comparative ranking of bids and comparative evaluation of baghouse vs. electrostatic precipitator. It concludes that it was decided to adopt a new electrostatic precipitator for particulate control as in large utility applications the electrostatic precipitator has developed to a level competitive with a baghouse. 2 references.

  5. Mineral phases and metals in baghouse dust from secondary ...

    Science.gov (United States)

    Baghouse dust (BHD) is a solid waste generated by air pollution control systems during secondary aluminum processing (SAP). Management and disposal of BHD can be challenging in the U.S. and elsewhere. In this study, the mineral phases, metal content and metal leachability of 78 BHD samples collected from 13 different SAP facilities across the U.S. were investigated. The XRD semi-quantitative analysis of BHD samples suggests the presence of metallic aluminum, aluminum oxide, aluminum nitride and its oxides, spinel, elpasolite as well as diaspora. BHD also contains halite, sylvite and fluorite, which are used as fluxes in SAP activities. Total aluminum (Al) in the BHD samples averaged 18% by weight. Elevated concentrations of trace metals (>100 µgL-1 As; >1000 µgL-1 Cu, Mn, Se, Pb, Mn and Zn) were also detected in the leachate. The U.S. toxicity characteristic leaching procedure (TCLP) results showed that some samples leached above the toxicity limit for Cd, Pb and Se. Exceeding the TCLP limits in all sample is independent of facilities generating the BHD. From the metal content perspective only, it appears that BHD has a higher potential to exhibit toxicity characteristics than salt cake (the largest waste stream generated by SAP facilities). The objective of this study was to investigate BHD from SAP facilities in the U.S. by determining the mineral phases and the metal (Al, As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, Se and Zn) content of the sample

  6. Using cement, lignite fly ash and baghouse filter waste for solidification of chromium electroplating treatment sludge

    OpenAIRE

    Wantawin, C.; Chobthiangtham, P.

    2004-01-01

    The objective of the study is to use baghouse filter waste as a binder mixed with cement and lignite fly ash to solidify sludge from chromium electroplating wastewater treatment. To save cost of solidification, reducing cement in binder and increasing sludge in the cube were focused on. Minimum percent cement in binder of 20 for solidification of chromium sludge was found when controlling lignite fly ash to baghouse filter waste at the ratio of 30:70, sludge to binder ratio of 0.5, water to m...

  7. Mineral phases and metals in baghouse dust from secondary aluminum production

    Science.gov (United States)

    Baghouse dust (BHD) is a solid waste generated by air pollution control systems during secondary aluminum processing (SAP). Management and disposal of BHD can be challenging in the U.S. and elsewhere. In this study, the mineral phases, metal content and metal leachability of 78...

  8. Effectiveness of a pressurized stormwater filtration system in Green Bay, Wisconsin: a study for the environmental technology verification program of the U.S. Environmental Protection Agency

    Science.gov (United States)

    Horwatich, J.A.; Corsi, Steven R.; Bannerman, Roger T.

    2004-01-01

    A pressurized stormwater filtration system was installed in 1998 as a stormwater-treatment practice to treat runoff from a hospital rooftop and parking lot in Green Bay, Wisconsin. This type of filtration system has been installed in Florida citrus groves and sewage treatment plants around the United States; however, this installation is the first of its kind to be used to treat urban runoff and the first to be tested in Wisconsin. The U.S. Geological Survey (USGS) monitored the system between November 2000 and September 2002 to evaluate it as part of the U.S. Environmental Protection Agency's Environmental Technology Verification Program. Fifteen runoff events were monitored for flow and water quality at the inlet and outlet of the system, and comparison of the event mean concentrations and constituent loads was used to evaluate its effectiveness. Loads were decreased in all particulate-associated constituents monitored, including suspended solids (83 percent), suspended sediment (81 percent), total Kjeldahl nitrogen (26 percent), total phosphorus (54 percent), and total recoverable zinc (62 percent). Total dissolved solids, dissolved phosphorus, and nitrate plus nitrite loads remained similar or increased through the system. The increase in some constituents was most likely due to a ground-water contribution between runoff events. Sand/silt split analysis resulted in the median silt content of 78 percent at the inlet, 87 percent at the outlet, and 3 percent at the flow splitter.

  9. Abatement of mercury emissions in the coal combustion process equipped with a Fabric Filter Baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Yan Cao; Chin-Min Cheng; Chien-Wei Chen; Mingchong Liu; Chiawei Wang; Wei-Ping Pan [Western Kentucky University (WKU), Bowling Green, KY (United States). Institute for Combustion Science and Environmental Technology (ICSET)

    2008-11-15

    The purpose of this study was to investigate the dependence of mercury emissions on coal ranks and electric utility boilers equipped with Fabric Filter Baghouses (FF). A comparison of mercury emission rates and fly ash properties was made between a circulating Fluidized Bed Combustor (CFBC) with FF and a Pulverized Coal (PC) combustor with FF during the burning of all three ranks of American coals. The data were collected from the Environmental Protection Agency Information Collection Request (EPA ICR) and WKU ICSET's mercury testing program. A statistical stepwise regression procedure was used to determine significant factors such as coal rank and types of boilers equipped with FF on mercury emissions during coal combustion. The higher mercury emission rates were generally found in both CFB and PC units when lignite was burned. The lower mercury emission rates were generally found in both CFB equipped with FF and PC units equipped with FF when bituminous coal was burned. There was a statistically significant lower mercury emission in the CFBC equipped with FF than that in the PC units when sub-bituminous coal was burned. Lower mercury emission rates in electric utility boilers equipped with FF are due to the active fly ash generated with a larger specific surface area and pore volume. Higher mercury emission rates observed during lignite-fired boilers may be due to their lower specific area of fly ash, which results from lower LOI, as well as the pore blockage by selenium (Se) for Texas lignite; and sodium (Na) and potassium (K) for North Dakota lignite. There is no significant mutual benefit for the mercury captured by the addition of Spray Dry Absorber (SDA) or selective non-catalytic reduction (SNCR) in the CFBC system. 25 refs., 8 figs., 2 tabs.

  10. Glomerular filtration rate

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007305.htm Glomerular filtration rate To use the sharing features on this page, please enable JavaScript. Glomerular filtration rate (GFR) is a test used to check ...

  11. Evaluation of an improved prototype mini-baghouse to control the release of respirable crystalline silica from sand movers.

    Science.gov (United States)

    Alexander, Barbara M; Esswein, Eric J; Gressel, Michael G; Kratzer, Jerry L; Feng, H Amy; Miller, Arthur L; Cauda, Emanuele; Heil, Graeham

    2017-10-20

    The OSHA final rule on respirable crystalline silica (RCS) will require hydraulic fracturing companies to implement engineering controls to limit workers' exposure to RCS. RCS is generated by pneumatic transfer of quartz-containing sand during hydraulic fracturing operations. Chronic inhalation of RCS can lead to serious disease, including silicosis and lung cancer. NIOSH research identified at least seven sources where RCS aerosols were generated at hydraulic fracturing sites. NIOSH researchers developed an engineering control to address one of the largest sources of RCS aerosol generation, RCS escaping from thief hatches on the top of sand movers. The control, the NIOSH Mini-Baghouse Retrofit Assembly (NMBRA), mounts on the thief hatches. Unlike most commercially-available engineering controls, the NMBRA has no moving parts and requires no power source. This article details the results of an evaluation of generation 3 of the NMBRA at a sand mine in Arkansas from May 19 - 21, 2015. During the evaluation, 168 area air samples were collected at 12 locations on and around a sand mover with and without the NMBRA installed. Analytical results for respirable dust and RCS indicated the use of the NMBRA effectively reduced concentrations of both respirable dust and RCS downwind of the thief hatches. Reductions of airborne respirable dust were estimated at 99+%; reductions in airborne RCS ranged from 98-99%. Analysis of bulk samples of the dust showed the likely presence of freshly fractured quartz, a particularly hazardous form of RCS. Use of an improved filter fabric and a larger area of filter cloth led to substantial improvements in filtration and pressures during these trials, as compared to the generation 2 NMBRA. Planned future design enhancements, including a weather cover, will increase the performance and durability of the NMBRA. Future trials are planned to evaluate the long-term operability of the technology.

  12. Rotary filtration system

    Science.gov (United States)

    Herman, David T [Aiken, SC; Maxwell, David N [Aiken, SC

    2011-04-19

    A rotary filtration apparatus for filtering a feed fluid into permeate is provided. The rotary filtration apparatus includes a container that has a feed fluid inlet. A shaft is at least partially disposed in the container and has a passageway for the transport of permeate. A disk stack made of a plurality of filtration disks is mounted onto the shaft so that rotation of the shaft causes rotation of the filtration disks. The filtration disks may be made of steel components and may be welded together. The shaft may penetrate a filtering section of the container at a single location. The rotary filtration apparatus may also incorporate a bellows seal to prevent leakage along the shaft, and an around the shaft union rotary joint to allow for removal of permeate. Various components of the rotary filtration apparatus may be removed as a single assembly.

  13. 40 CFR 141.174 - Filtration sampling requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration sampling requirements. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.174 Filtration sampling requirements. (a) Monitoring...

  14. 40 CFR 141.171 - Criteria for avoiding filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for avoiding filtration. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.171 Criteria for avoiding filtration. In addition to the...

  15. CENTRIFUGAL MEMBRANE FILTRATION

    Energy Technology Data Exchange (ETDEWEB)

    William A. Greene; Patricia A. Kirk; Richard Hayes; Joshua Riley

    2005-10-28

    SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, has engineered and developed a system for use within the U.S. Department of Energy (DOE) Environmental Management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. SpinTek II High Shear Rotary Membrane Filtration System is a unique compact crossflow membrane system that has large, demonstrable advantages in performance and cost compared to currently available systems: (1) High fluid shear prevents membrane fouling even with very high solids content; hazardous and radioactive components can be concentrated to the consistency of a pasty slurry without fouling. (2) Induced turbulence and shear across the membrane increases membrane flux by a factor of ten over existing systems and allows operation on fluids not otherwise treatable. (3) Innovative ceramic membrane and mechanical sealing technology eliminates compatibility problems with aggressive DOE waste streams. (4) System design allows rapid, simple disassembly for inspection or complete decontamination. (5) Produces colloidal- and suspended-solids-free filtrate without the addition of chemicals. The first phase of this project (PRDA maturity stage 5) completed the physical scale-up of the SpinTek unit and verified successful scale-up with surrogate materials. Given successful scale-up and DOE concurrence, the second phase of this project (PRDA maturity stage 6) will provide for the installation and

  16. Comparison of baghouse test results with the GCA/EPA design model

    Energy Technology Data Exchange (ETDEWEB)

    Viner, A.S.; Donovan, R.P.; Ensor, D.S.; Hovis, L.S.

    1984-08-01

    The GCA/EPA fabric filter design model is evaluated for its ability to predict pressure drop, penetration, and dynamics of full-scale baghouses. Model predictions are compared with data measured at the Kramer station of the Nebraska Public Power District. Two different values of specific resistance coefficient (K/sub 2/) and effective residual drag (S/sub E/) are used in the modeling of the Kramer baghouse. The field-measured value of K/sub 2/ combined with the laboratory-measured value of S/sub E/ produces the best predictions of pressure-drop performance, but the field data exhibit fluctuations that cannot be accounted for by the model. The model overpredicts penetration just after a compartment has been cleaned; but, as the dust cake on the filter grows, the discrepancy between predicted and measured values diminishes. 15 references.

  17. Visualization of water flow during filtration using flat filtration materials

    OpenAIRE

    Hrůza Jakub; Šidlof Petr; Bílek Petr

    2012-01-01

    Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homo...

  18. A new testing facility to characterize ESD hazards in industrial baghouse filters

    OpenAIRE

    Mauger, Samuel; Perrette, Lionel; Ollier, Yannick; Petitfrere, Claire; Boudalaa, Mohamed

    2008-01-01

    International audience; Baghouse filters are common dust collection systems for pneumatic transport processes involving finely divided powder materials. However, safe use of these systems requires appropriate control of electrostatic charge and discharge phenomena. Numerous parameters may contribute to accidental inflammation due to uncontrolled ESDs. This is the reason why the experimental approach keeps the best way to investigate these complex hazards. The facility has been instrumented to...

  19. Using cement, lignite fly ash and baghouse filter waste for solidification of chromium electroplating treatment sludge

    Directory of Open Access Journals (Sweden)

    Wantawin, C.

    2004-02-01

    Full Text Available The objective of the study is to use baghouse filter waste as a binder mixed with cement and lignite fly ash to solidify sludge from chromium electroplating wastewater treatment. To save cost of solidification, reducing cement in binder and increasing sludge in the cube were focused on. Minimum percent cement in binder of 20 for solidification of chromium sludge was found when controlling lignite fly ash to baghouse filter waste at the ratio of 30:70, sludge to binder ratio of 0.5, water to mixer ratio of 0.3 and curing time of 7 days. Increase of sludge to binder ratio from 0.5 to 0.75 and 1 resulted in increase in the minimum percent cement in binder up to 30 percent in both ratios. With the minimum percent cement in binder, the calculated cement to sludge ratios for samples with sludge to binder ratios of 0.5, 0.75 and 1 were 0.4, 0.4 and 0.3 respectively. Leaching chromium and compressive strength of the samples with these ratios could achieve the solidified waste standard by the Ministry of Industry. For solidification of chromium sludge at sludge to binder ratio of 1, the lowest cost binder ratio of cement to lignite fly ash and baghouse filter waste in this study was 30:21:49. The cost of binder in this ratio was 718 baht per ton dry sludge.

  20. Results of a baghouse operation and maintenance survey on industry and utility coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.; Kreidenweis, S.; Theodore, L.

    1983-04-01

    In 1979, the results of an operation and maintenance fabric filter survey conducted by APAC were presented. In view of the potential usefulness of such information, Manhattan college was requested by APAC to follow up the initial survey with another improved version. To maximize the usefulness and insure a greater degree of validity to the conclusions, it was decided to limit the participants to users of coal-fired boilers only. A more comprehensive questionaire and one more suitable to computer interpretation than that used in the first study was developed and employed. In this paper, the results of an analysis of these data are presented. Some of the conclusions and opinions of the authors include: (1) Bag life may well be greater than the 2-3 yr reported in the literature, a fact that could reduce projected operating costs for proposed units. (2) Abrasion/erosion difficulties, once a major factor for baghouse users, apparently has been resolved by the equipment manufacturers. (3) Compliance is not a problem with the baghouse. (4) Both utilities and industry would recommend a baghouse to control fly ash for other boilers. (5) O and M problems are more severe with pulse-jet than with reverse-air systems. (6) The three most prevalent O and M problems appear to be higher than design pressure drop, bag failure, and the fly ash handling system.

  1. Size-dependent penetration of trace elements through a utility baghouse

    Science.gov (United States)

    Shendrikar, A. D.; Ensor, D. S.; Cowen, S. J.; Woffinden, G. J.; McElroy, M. W.

    Particle size-dependent concentrations of 35 major and minor trace elements were measured at the inlet and outlet of a fabric filter baghouse installed on a western pulverized coal-fired power plant. Size-segregated particulate samples were collected using University of Washington impactors with Kapton collection disks coated with Apiezon-L grease. The impactor samples were analyzed for trace elements using neutron activation analysis. The inlet particle size distribution for most elements was bimodal, with the larger mode having a geometric mean diameter of approximately 4-10 μm and the smaller mode having a geometric mean diameter of 0.08 μm or less. In general, individual trace elements exhibited size distributions similar to total mass. However, several elements, including As, Se, Sb, Hg, Cl, Zn and Ni, showed noticeably 'flatter' size distributions with proportionally higher concentrations in submicrometer particles compared to total mass. The elemental penetrations through the baghouse generally agreed well with the mass penetration. An exception is Se, which shows penetration an order of magnitude higher than that of total mass and other elements. Most trace elements were removed by the baghouse with greater than 95 % collection efficiency over the entire particle size range.

  2. Baghouse permit restrictions: What are the real limitations during unit start-up?

    Energy Technology Data Exchange (ETDEWEB)

    Gosoroski, S.; Gibson, B.; Mistal, F.; Wight, D.

    1998-07-01

    Air permits for utility baghouses often impose time limitations on baghouse bypassing during start-up operation. Specific conditions of the Clover Project (2 x 440 MW units) state that fabric filters shall operate when coal is being fired in the main boiler except for thirty minutes during each start-up. With these imposed limitations of air permits, it is necessary to determine the technical feasibility of the equipment to meet the bypass time constraint. Considerations of the equipment include: Achieving a minimum acceptable boiler outlet temperature of 280 F entering the baghouse for corrosion considerations. Determining if the oil to coal transition can be accomplished to an acceptable heat input ratio of oil to coal to meet manufacturer limitations. Boiler capability to achieve the ramp rate required in ramping from maximum load on oil (11% of MCR) to required load to achieve the minimum boiler outlet temperature. Determining if the turbine ramp rate falls within a reasonable fatigue index. Effects of fly ash loading on scrubber operations. This paper will examine the permit limitations and technical feasibility of achieving these conditions.

  3. Influence of coal-specific fly ash properties upon baghouse performance: a comparison of two extreme examples

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.; Sears, D.R.

    1984-01-01

    Pilot plant data with a large number of lignite and subbituminous coals have demonstrated that shaker baghouse efficiency is highly coal specific with large differences in baghouse penetration for different coals. A previous report has presented these findings along with an observed correlation between elemental fly ash composition and baghouse penetration. This paper presents a further investigation of the relationship between fly ash properties and baghouse penetration with woven glass fabric and shaker cleaning. The focus will be on two coals which represent the good and poor extremes of filter performance. The coal and ash properties of a lignite showing good filter performance are compared with the properties of a lignite demonstrating very poor performance. An examination of both chemical and physical ash properties which include elemental compositions as a function of size, particulate size distribution, particle surface morphology, and other physical descriptors is presented in an attempt to determine causes of grossly different baghouse performance. The work described in this paper was not funded by the US Environmental Protection Agency and therefore the contents do not necessarily reflect the views of the Agency and no official endorsement shoud be inferred. 12 references.

  4. Foamed glass insulating block ends costly baghouse corrosion and protects new steel stack

    Energy Technology Data Exchange (ETDEWEB)

    1982-03-01

    A secondary smelter company on the West Coast, that reclaims certain metals from scrap products such as wet cell batteries, was spending hundreds of thousands of dollars each year to replace corroded metal in the baghouses at one of its installations. Various types of protective coatings and special steels had been tried, but the maximum life of each unit was about a year due to condensation of flue gas corrosives on the inside surface of the metal walls. In 1979, at one of its sites, the company decided to test an acid/corrosion protection system specifically designed for stack, duct, and breeching installations and related equipment. The system consists of totally inorganic formed borosilicate glass block that can handle temperatures to 960/sup 0/F and is resistant to atttack by most acids and corrosives except fluorides and strong alkalis. The closed-cell structure provides a strong, lightweight product that reduces installation costs, and has extremely low thermal conductivity for an efficient heat barrier. The 12 X 18'' block is directly bonded to a clean metal surface by an 1/8'' thick layer of urethane asphalt that forms a virtually impervious flexible membrane to further protect the metal from corrosive attack. The flexible bond also absorbs expansion and contraction due to thermal changes, and reduces the probability of cracked blocks and dropoff. The protection provided by the foamed glass block and adhesive membrane system has eliminated the very expensive annual replacement of corroded baghouse walls. The performance of the lining system in the baghouses was so successful that the smelter decided to use it in a new metal stack that is 165' high.

  5. Filtration in Porous Media

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander

    There is a considerable and ongoing effort aimed at understanding the transport and the deposition of suspended particles in porous media, especially non-Fickian transport and non-exponential deposition of particles. In this work, the influential parameters in filtration models are studied...... to understand their effects on the non-Fickian transport and the non-exponential deposition. The filtration models are validated by the comparisons between the modelling results and the experimental data.The elliptic equation with distributed filtration coefficients may be applied to model non-Fickian transport...... and hyperexponential deposition. The filtration model accounting for the migration of surface associated particles may be applied for non-monotonic deposition....

  6. Water Filtration Products

    Science.gov (United States)

    1986-01-01

    American Water Corporation manufactures water filtration products which incorporate technology originally developed for manned space operations. The formula involves granular activated charcoal and other ingredients, and removes substances by catalytic reactions, mechanical filtration, and absorption. Details are proprietary. A NASA literature search contributed to development of the compound. The technology is being extended to a deodorizing compound called Biofresh which traps gas and moisture inside the unit. Further applications are anticipated.

  7. Results of a baghouse operation and maintenance survey on industry and utility coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.

    1983-04-01

    The replies to a questionnaire are analyzed and conclusions are drawn from the results obtained. These include: bag life may well be greater than the 2-3 years reported in the literature; abrasion/erosion difficulties have apparently not been resolved by the equipment manufacturers; compliance with regulations is not a problem with the baghouse; operation and maintenance problems are more severe with pulse-jet than with reverse-air systems; the three most prevalent operation and maintenance, problems appear to be higher-than-design pressure drop, bag failure, and the fly ash handling system.

  8. Spray dryer/baghouse system testing - CRADA 92-001. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H. W.

    1992-04-28

    A series of seven tests were conducted to evaluate the effectiveness of scrubbing both NO{sub 2} and SO{sub 2} in a spray dryer/baghouse system. The operating conditions specified were a high spray dryer inlet temperature (500{degrees}F), and a high spray dryer outlet temperature (250 to 300 {degrees}F). The data required to adequately evaluate the effectiveness of this technology is enclosed. Discussion of some of the variables as well as an itemized list of the testing information is part of the report.

  9. Baghouse on a glass furnace provides lesson in filter bag specification

    Energy Technology Data Exchange (ETDEWEB)

    Carney, K.E.; King, W.R.

    1983-09-01

    This paper, directed toward individuals who specify filter bags for industrial dust collectors, is a case history illustrating the need for a complete bag specification. The case history documents Owens-Corning Fiberglas solution to a glass bag failure that occurred during the start-up of a new baghouse on a gas fired glass furnace. Based on the chemical and physical testing described in this paper, the conclusion was reached that the early problems were due to a lack of precess understanding and attention to the bag specification. The process has operated satisfactorily with the respecified glass bag.

  10. Visualization of water flow during filtration using flat filtration materials

    Directory of Open Access Journals (Sweden)

    Hrůza Jakub

    2012-04-01

    Full Text Available Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  11. Visualization of water flow during filtration using flat filtration materials

    Science.gov (United States)

    Bílek, Petr; Šidlof, Petr; Hrůza, Jakub

    2012-04-01

    Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  12. Use of sorbents for air toxics control in a pilot-scale COHPAC baghouse

    Energy Technology Data Exchange (ETDEWEB)

    Butz, J.R.; Chang, R.; Waugh, E.G.; Jensen, B.K.; Lapatnick, L.N.

    1999-07-01

    With funding from EPRI and Public Service Electric and Gas (PSE and G), ADA Technologies has been operating a COHPAC (COmpact Hybrid PArticulate Collector) pulse-jet pilot plant at PSE and G's Hudson station in Jersey City, NJ to expand the application of COHPAC in anticipation of hazardous air pollutants (HAP) regulations. The pilot extracts a slipstream of flue gas from downstream of Hudson's full-scale ESP (a four-field Research Cottrell unit). A series of tests has been run over the past two and one-half years to evaluate the injection of dry sorbents upstream of the COHPAC pilot for removal of acid gases and mercury from the flue gas slipstream. The COHPAC baghouse subsequently removes the sorbent material from the flue gas. Gas samples were taken upstream of sorbent injection and downstream of the pilot to characterize the ability of the sorbents to remove targeted HAPs. The operation of the pilot was also monitored during testing to characterize the impact of sorbent injection on the performance of the baghouse. Data collected during 1998 are compared to data from 1997, when the pilot was operated at a higher air-to-cloth ratio.

  13. Conversion of elemental mercury to the oxidized form in a fabric filter baghouse

    Energy Technology Data Exchange (ETDEWEB)

    McManus, T.J.; Agbede, R.O.; Khosah, R.P. [Advanced Technology Systems, Inc., Monroeville, PA (United States)

    1998-12-31

    The US Department of Energy`s Federal Energy Technology Center (DOE-FETC) has in the last several years funded efforts on identifying a sampling and analytical method to differentiate and quantify the chemical forms of mercury emitted from coal-fired electric utility boilers. DOE-FETC requested Advanced Technology Systems, Inc. (ATS) to develop new methodologies for determining the chemical species of mercury in coal flue gas, either by the modification of existing ones or by the introduction of novel methods. Through the efforts of ATS and others, this goal was attained and demonstrated by the final validation of the Ontario-Hydro Method. Also, in these mercury method comparison studies performed by ATS, conversion of elemental mercury to oxidized mercury in a fabric filter baghouse was observed. Investigation of this type of phenomenon was a step beyond mercury species measurement in that this had an impact on the design of mercury control devices for coal-fired power plants which must be mercury species-specific. Moreover, long and short term transport and deposition into the ecosystem with the resulting human and animal toxicity are the ultimate concerns and are all dependent upon the mercury species involved. Results will be reported from a five day study in which mercury species were measured and identified utilizing the Ontario-Hydro Method at the outlet of a baghouse accepting natural gas flue gas spiked with various mercury species.

  14. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    Depaoli, D. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes.

  15. Fabric filter technology for utility coal-fired power plants. Part II. Application of baghouse technology in the electric utility industry

    Energy Technology Data Exchange (ETDEWEB)

    Carr, R.C.; Smith, W.B.

    1984-02-01

    This, the second in a series of papers, discusses the experience of electric utilities in applying baghouse technology for the collection of particulate matter at coal-fired electric power generating plants. The history of baghouse technology in the US is traced, and past and present research and development to build a data base for the technology in application in the electric utility industry is described.

  16. Water Treatment Technology - Filtration.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on filtration provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purposes of sedimentation basins and flocculation…

  17. Modeling sorbent injection for mercury control in baghouse filters: I--model development and sensitivity analysis.

    Science.gov (United States)

    Flora, Joseph R V; Hargis, Richard A; O'Dowd, William J; Pennline, Henry W; Vidic, Radisav D

    2003-04-01

    A two-stage mathematical model for Hg removal using powdered activated carbon injection upstream of a baghouse filter was developed, with the first stage accounting for removal in the ductwork and the second stage accounting for additional removal caused by the retention of carbon particles on the filter. The model shows that removal in the ductwork is minimal, and the additional carbon detention time from the entrapment of the carbon particles in the fabric filter enhances the Hg removal from the gas phase. A sensitivity analysis on the model shows that Hg removal is dependent on the isotherm parameters, the carbon pore radius and tortuosity, the C/Hg ratio, and the carbon particle radius.

  18. Modeling sorbent injection for mercury control in baghouse filters: I - model development and sensitivity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Joseph R.V. Flora; Richard A. Hargis; William J. O' Dowd; Henry W. Pennline; Radisav D. Vidic [University of South Carolina, Columbia, SC (United States). Department of Civil and Environmental Engineering

    2003-04-01

    A two-stage mathematical model for mercury (Hg) removal using powdered activated carbon injection upstream of a baghouse filter was developed, with the first stage accounting for removal in the ductwork and the second stage accounting for additional removal caused by the retention of carbon particles on the filter. The model shows that removal in the ductwork is minimal, and the additional carbon detention time from the entrapment of the carbon particles in the fabric filter enhances the Hg removal from the gas phase. A sensitivity analysis on the model shows that Hg removal is dependent on the isotherm parameters, the carbon pore radius and tortuosity, the C/Hg ratio, and the carbon particle radius. 23 refs., 8 figs., 1 tab.

  19. Caustic leach-electrowin process for treating electric arc furnace baghouse dust. Final report. 2 volumes

    Energy Technology Data Exchange (ETDEWEB)

    1983-03-01

    This report investigates the feasibility of one method of removing zinc and lead from electric arc furnace baghouse dust on a laboratory scale. Recent studies and literature are reviewed with attention being given to the formation and characterization of dust. Alternative treatment and disposal options are briefly described. Caustic leach-electrowin testwork is reported. Based on the results of the testwork, flowsheets and material balances are derived and used for the conceptual design of a slave plant to treat 15,000 tonnes per year of dust to produce zinc metal. Target economics, comprising preliminary estimates of capital and operating costs and revenues using somewhat optimistic assumptions, are calculated based on recycling of leach residue to the electric arc furnaces. Economic, commercial and other considerations pertaining to treating dust at a slave plant as compared to a centralized facility are discussed. Conclusions and recommendations for further work are enumerated. 10 figs., 14 tabs.

  20. Characterization of NO[sub 2] and SO[sub 2] removals in a spray dryer/baghouse system

    Energy Technology Data Exchange (ETDEWEB)

    O' Dowd, W.J.; Markussen, J.M.; Pennline, H.W. (Dept. of Energy, Pittsburgh, PA (United States)); Resnik, K.P. (Gilbert/Commonwealth, Inc., Library, PA (United States))

    1994-11-01

    Oxidation of NO to NO[sub 2] has been proposed as a method for enhancing NO[sub x] removals in conventional flue gas desulfurization (FGD) processes. This experimental investigation characterizes the removals of NO[sub 2] and SO[sub 2] in a 1.1 m[sup 3](standard)/min spray dryer/baghouse system. Flue gas was generated by burning a No. 2 fuel oil, which was subsequently spiked upstream of the spray dryer with NO[sub 2] or SO[sub 2] or both. Lime slurry was injected via a rotary atomizer into the spray dryer. Variables studied include the approach to the adiabatic saturation temperature, stoichiometric ratio, SO[sub 2] concentration, and NO[sub 2] concentration. Significant quantities of NO[sub 2] are scrubbed in this system, and over half of the total removal (at inlet NO[sub 2] > 400 ppm) occurs in the baghouse. Increasing NO[sub 2] concentrations enhance the amount of NO[sub x] removed in the system. Also, the presence of significant quantities of NO[sub 2] enhances the baghouse SO[sub 2] removal. Although up to 72% NO[sub 2] removals were obtained, concentrations of NO[sub 2] that exited the system were greater than 50 ppm for all conditions investigated.

  1. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    DePaoli, D.W.; Tsouris, C. [Oak Ridge National Lab., TN (United States); Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  2. Latest aspects of mechanical filtration

    OpenAIRE

    Stanislav Koláček; Michal Černý

    2013-01-01

    The aim of this study was to describe and unify all knowledge about mechanic filtration. The first part deals with the parameters and properties of filtration. Here some important basic concepts are explained such as pressure gradient, filter life, etc. There’s also a description of convenient filtration technology for coarse and fine materials, such as sand, smoke or soot. The second part primarily focuses on the real use and application of filters for liquid and gaseous media. The differenc...

  3. Combustion testing of ceramic coal-water (CWF) atomizers in Unit No. 1 Chatham New Brunswick generating station, final report, baghouse demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Rankin, D.M.

    1986-01-01

    The baghouse demonstration project was undertaken at New Brunswick Power's Chatham thermal generating plant. A number of objectives were outlined: 1) to reduce the particulate in the fuel gas while burning coal water fuel (CWF); 2) to obtain performance data on different fabrics to assist in the selection of filter bags for a CWF demonstration, and, 3) to establish a procedure for operating a baghouse when burning fuel oil, fuel oil and CWF, CWF, and switching between different modes of operation. The demonstration showed that combined firing of CWF and heavy fuel oil can be handled by a baghouse, and indicate that the Nomex fabrix was the most effective of the three tested. Extensive appendices are included. 15 figs., 6 tabs.

  4. Filtration properties of nonwovens.

    Science.gov (United States)

    Gador, W; Jankowska, E

    1999-01-01

    This paper presents the results and conclusions from experimental investigations concerning filtration properties of nonwovens. The needled nonwovens were made from polyester fibres (PTE) with average fibre diameter 12 micrometres and polypropylene fibres (PP) with average fibre diameter 32 micrometres. Nonwovens were produced out of each of those fibres or out of a mixture of polyester and polypropylene fibres. This paper also presents investigations of nonwoven fabric made of polypropylene fibres (PP) with average fibre diameter 2.6 micrometres, which was formed according to melt-blown technology. Oil mist, as challenge aerosol, was used to evaluate the performance of filter media at various aerosol velocities. The average oil mist test aerosol particle diameter was 0.3 micrometre. Filter penetration was measured at oil mist concentration 0.24 g/m(3).

  5. Andersen Filtration and Hard Lefschetz

    OpenAIRE

    Soergel, Wolfgang

    2006-01-01

    On the space of homomorphisms from a Verma module to an indecomposable tilting module of the BGG-category O we define a natural filtration following Andersen and establish a formula expressing the dimensions of the filtration steps in terms of coefficients of Kazhdan-Lusztig polynomials.

  6. Air filtration in HVAC systems

    CERN Document Server

    Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

    2010-01-01

    Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

  7. Baghouse Slipstream Testing at TXU's Big Brown Station

    Energy Technology Data Exchange (ETDEWEB)

    John Pavlish; Jason Laumb; Robert Jensen; Jeffery Thompson; Christopher Martin; Mark Musich; Brandon Pavlish; Stanley Miller; Lucinda Hamre

    2007-04-30

    Performing sorbent testing for mercury control at a large scale is a very expensive endeavor and requires months of planning and careful execution. Even with good planning, there are plant limitations on what operating/design parameters can be varied/tested and when. For parameters that cannot be feasibly tested at the full scale (lower/higher gas flow, different bag material, cleaning methods, sorbents, etc.), an alternative approach is used to perform tests on a slipstream unit using flue gas from the plant. The advantage that a slipstream unit provides is the flexibility to test multiple operating and design parameters and other possible technology options without risking major disruption to the operation of the power plant. Additionally, the results generated are expected to simulate full-scale conditions closely, since the flue gas used during the tests comes directly from the plant in question. The Energy & Environmental Research Center developed and constructed a mobile baghouse that allows for cost-effective testing of impacts related to variation in operating and design parameters, as well as other possible mercury control options. Multiple sorbents, air-to-cloth ratios, bag materials, and cleaning frequencies were evaluated while flue gas was extracted from Big Brown when it fired a 70% Texas lignite-30% Powder River Basin (PRB) blend and a 100% PRB coal.

  8. Mineral phases and metals in baghouse dust from secondary aluminum production.

    Science.gov (United States)

    Huang, Xiao-Lan; El Badawy, Amro M; Arambewela, Mahendranath; Adkins, Renata; Tolaymat, Thabet

    2015-09-01

    Baghouse dust (BHD) is a solid waste generated by air pollution control systems during secondary aluminum processing (SAP). Management and disposal of BHD can be challenging in the U.S. and elsewhere. In this study, the mineral phases, metal content and metal leachability of 78 BHD samples collected from 13 different SAP facilities across the U.S. were investigated. The XRD semi-quantitative analysis of BHD samples suggests the presence of metallic aluminum, aluminum oxide, aluminum nitride and its oxides, spinel, elpasolite as well as diaspora. BHD also contains halite, sylvite and fluorite, which are used as fluxes in SAP activities. Total aluminum (Al) in the BHD samples averaged 18% by weight. Elevated concentrations of trace metals (>100 μg L(-1) As; >1000 μg L(-1) Cu, Mn, Se, Pb, Mn and Zn) were also detected in the leachate. The U.S. toxicity characteristic leaching procedure (TCLP) results showed that some samples leached above the toxicity limit for Cd, Pb and Se. Exceeding the TCLP limits in all sample is independent of facilities generating the BHD. From the metal content perspective only, it appears that BHD has a higher potential to exhibit toxicity characteristics than salt cake (the largest waste stream generated by SAP facilities). Published by Elsevier Ltd.

  9. Particulate characterization. Final report for the period ending March 31, 1986. [Baghouse operating efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.; Laudal, D.L.

    1986-06-01

    The primary focus is on characteristics which are critical to particulate control device performance and the environment for western low-rank coals. The concern is that the control device removal efficiency is reduced for particles less than 2..mu..m diameter and these fine particles represent a potential health hazard. Fly ash particle size distribution, morphology, composition, and ash cohesiveness were measured and related to the level of fine particle emissions from the baghouse and to the specific coal. A major finding of the study is that fine particulate emissions from a fabric filter are coal specific. That is, some coals produce fly ash which is easily collected while others produce fly ash with a smooth surface texture and low ash cohesiveness resulting in a difficult-to-collect ash. Tests were also conducted to determine the effect of micronizing the coal (mass median diameter approximately 10 ..mu..m) on the amount of respirable particulate matter produced. Results from combustion tests of two coals show that reduction in coal particle size reduces the median fly ash diameter and significantly increases submicron particle production. Trace element fly ash particle size studied for a micronized and a normal grind Texas lignite showed that selenium was the most highly enriched element in the submicron particles but there was also significant submicron enrichment of barium and vanadium for both coals. A method to reduce fine particulate emissions for difficult-to-collect ash was developed.

  10. Performance of a baghouse utilizing expanded PTFE membrane filter media at a refuse-derived fuel power plant

    Energy Technology Data Exchange (ETDEWEB)

    Fritsky, K.J.; Hurley, J.E.

    1999-07-01

    Great River Energy (GRE), formerly United Power Association, operates a 1,000 TPD refuse-derived fuel (RDF) fired waste-to energy facility in Elk River, Minnesota. The plant produces approximately 32 MW (gross) from three boiler units with traveling stoker grates. Flue gas from the boilers enter a dry lime scrubber prior to an eight module, reverse air baghouse. This paper presents emissions, pressure drop, and cleaning energy data before and after installation of the expanded PTFE (ePTFE) membrane filter bags. After 24 months of operation, the average concentration of total particulate matter (dry + organic wet catch) with the original conventional fiberglass filter bags was 0.007 gr/dscf {at} 7% O{sub 2}. The average concentration of total particulate matter (dry + organic wet catch) with ePTFE membrane filter bags was reduced to 0.004 gr/dscf {at} 7% O{sub 2}. To keep from exceeding 10--12 inches w.g. of pressure drop across the baghouse at full load after 24 months of service, two reverse air fans and sonic horns in each module were used to clean the original fiberglass bags. The frequency of cleaning was continuous with 100 cleaning cycles per 24 hours. With the ePTFE membrane filter bags, a baghouse pressure drop of 7 inches w.g. was maintained after 24 months of operation at full load. In order to clean the new bags, sonic horns were used. However, one of the two reverse air fans was turned off. The cleaning frequency was reduced to 15 cycles per 24 hours. Other benefits are also discussed including energy cost savings due to reduced power consumption and increased power generation capacity.

  11. Problems of multiphase fluid filtration

    CERN Document Server

    Konovalov, AN

    1994-01-01

    This book deals with a spectrum of problems related to the mathematical modeling of multiphase filtration. Emphasis is placed on an inseparable triad: model - algorithm - computer code. An analysis of new and traditional filtration problems from the point of view of both their numerical implementation and the reproduction of one or another technological characteristics of the processes under consideration is given. The basic principles which underlie the construction of efficient numerical methods taking into account the filtration problems are discussed: non-evolutionary nature, degeneration,

  12. Filtration model of plastic flow

    Science.gov (United States)

    Sarychev, Vladimir D.; Nevskii, Sergey A.; Cheremushkina, Elena V.; Gromov, Victor E.; Aifantis, Elias C.

    2014-12-01

    A filtration model for plastic flow based on the idea of a deformed material considered as a two-phase heterogeneous medium has been suggested. In this approach, the wave displacement is regarded as a shock transition in the medium. One of the phases (the excited one) is responsible for system restructuring, and the other phase (the normal one) is unrelated to structural transformations. The plastic wave is the result of the interaction of these two phases. The governing equations for the filtration model are obtained. They include the laws of momentum and mass conservation, as well as the filtration ratio of the phases.

  13. Filtration characteristics in membrane bioreactors

    NARCIS (Netherlands)

    Evenblij, H.

    2006-01-01

    Causes of and remedies for membrane fouling in Membrane Bioreactors for wastewater treatment are only poorly understood and described in scientific literature. A Filtration Characterisation Installation and a measurement protocol were developed with the aim of a) unequivocally determination and

  14. Latest aspects of mechanical filtration

    Directory of Open Access Journals (Sweden)

    Stanislav Koláček

    2013-01-01

    Full Text Available The aim of this study was to describe and unify all knowledge about mechanic filtration. The first part deals with the parameters and properties of filtration. Here some important basic concepts are explained such as pressure gradient, filter life, etc. There’s also a description of convenient filtration technology for coarse and fine materials, such as sand, smoke or soot. The second part primarily focuses on the real use and application of filters for liquid and gaseous media. The differences in construction between different types of filters for filtration of fuels, oils, hydraulic fluids, air and cabin filters are described. The last section is focused mainly on new materials for the production of filters. These materials are ceramic or nanomaterials, which can actually be enriched for example with antibacterial silver or some fungicides.

  15. Characterization of vapor phase mercury released from concrete processing with baghouse filter dust added cement.

    Science.gov (United States)

    Wang, Jun; Hayes, Josh; Wu, Chang-Yu; Townsend, Timothy; Schert, John; Vinson, Tim; Deliz, Katherine; Bonzongo, Jean-Claude

    2014-02-18

    The fate of mercury (Hg) in cement processing and products has drawn intense attention due to its contribution to the ambient emission inventory. Feeding Hg-loaded coal fly ash to the cement kiln introduces additional Hg into the kiln's baghouse filter dust (BFD), and the practice of replacing 5% of cement with the Hg-loaded BFD by cement plants has recently raised environmental and occupational health concerns. The objective of this study was to determine Hg concentration and speciation in BFD as well as to investigate the release of vapor phase Hg from storing and processing BFD-added cement. The results showed that Hg content in the BFD from different seasons ranged from 0.91-1.44 mg/kg (ppm), with 62-73% as soluble inorganic Hg, while Hg in the other concrete constituents were 1-3 orders of magnitude lower than the BFD. Up to 21% of Hg loss was observed in the time-series study while storing the BFD in the open environment by the end of the seventh day. Real-time monitoring in the bench system indicated that high temperature and moisture can facilitate Hg release at the early stage. Ontario Hydro (OH) traps showed that total Hg emission from BFD is dictated by the air exchange surface area. In the bench simulation of concrete processing, only 0.4-0.5% of Hg escaped from mixing and curing BFD-added cement. A follow-up headspace study did not detect Hg release in the following 7 days. In summary, replacing 5% of cement with the BFD investigated in this study has minimal occupational health concerns for concrete workers, and proper storing and mixing of BFD with cement can minimize Hg emission burden for the cement plant.

  16. Health benefits of particle filtration.

    Science.gov (United States)

    Fisk, W J

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, for example, 7% to 25%. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air. Published 2013. This article is a US Government work and is in the public domain in the USA.

  17. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  18. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  19. Modeling sorbent injection for mercury control in baghouse filters: II--pilot-scale studies and model evaluation.

    Science.gov (United States)

    Flora, Joseph R V; Hargis, Richard A; O'Dowd, William J; Pennline, Henry W; Vidic, Radisav D

    2003-04-01

    Activated carbon injection for Hg control in a 500-lb/hr pilot-scale coal-fired furnace equipped with a fabric filter for particulate control was evaluated at different operating conditions. The pilot-scale tests showed that Hg removal was improved at lower temperatures and higher C/Hg ratios. The two-stage mathematical model developed to describe Hg removal using powdered activated carbon injection upstream of a baghouse filter was used to obtain Langmuir isotherm parameters as a function of temperature by fitting the model to a subset of experimental data. The predictive capability of the model was then tested by comparing model calculations with additional experimental data from this system obtained using different operating temperatures and sorbent to Hg ratios. Model predictions were in good agreement with experimentally measured Hg removal efficiency. Based on the model predictions, Hg removal in the duct appears to be limited and higher C/Hg ratio, lower operating temperature, and longer cleaning cycle of the baghouse filter should be utilized to achieve higher Hg removal in this system.

  20. Modeling sorbent injection for mercury control in baghouse filters: II - pilot-scale studies and model evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Joseph R.V. Flora; Richard A. Hargis; William J. O' Dowd; Henry W. Pennline; Radisav D. Vidic [University of South Carolina, Columbia, SC (United States). Department of Civil and Environmental Engineering

    2003-04-01

    Activated carbon injection for Hg control in a 500-lb/hr pilot-scale coal-fired furnace equipped with a fabric filter for particulate control was evaluated at different operating conditions. The pilot-scale tests showed that Hg removal was improved at lower temperatures and higher C/Hg ratios. The two-stage mathematical model developed to describe Hg removal using powdered activated carbon injection upstream of a baghouse filter was used to obtain Langmuir isotherm parameters as a function of temperature by fitting the model to a subset of experimental data. The predictive capability of the model was then tested by comparing model calculations with additional experimental data from this system obtained using different operating temperatures and sorbent to Hg ratios. Model predictions were in good agreement with experimentally measured Hg removal efficiency. Based on the model predictions, Hg removal in the duct appears to be limited and higher C/Hg ratio, lower operating temperature, and longer cleaning cycle of the baghouse filter should be utilized to achieve higher Hg removal in this system. 27 refs., 8 figs., 3 tabs.

  1. Low Temperature Particle Filtration of Wood Gas with Low Tar Content

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik Birk; Bentzen, Jens Dall

    2002-01-01

    Baghouse filters and cartridge filters were tested online with wood gas from a two stage down draft gasifier. The gas contained soot and very low levels (10-30 mg/Nm³) of tar. Particle collection efficiencies were above 95%. Continuous operation with cheap self cleaning baghouse filters were tested...

  2. Filtration and compression of organic materials

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    is to use more simple systems. Dextran-MnO2 particles and polystyrene particles with a water-swollen polyacrylic acid shell have therefore been synthesised. These particles have been filtered and used to study the non-linear filtration behaviour. The compressibility of the formed cake has been investigated......The conventional filtration theory has been based on filtrations of incompressible particles such as anatase, kaolin and clay. The filtration models have later been used for organic slurries but can often not explain the observed experimental data. At constant pressure, the filtrate volume does...... and the discrepancy between the filtration theory and the observed filtration behaviour explained as a time-dependent collapse of the formed cake (creep). Thus, the creep phenomenon has been adopted in the conventional filtration models and it will be shown that the model can be used to simulate filtration data...

  3. Optimization of suspensions filtration with compressible cake

    Directory of Open Access Journals (Sweden)

    Janacova Dagmar

    2016-01-01

    Full Text Available In this paper there is described filtering process for separating reaction mixture after enzymatic hydrolysis to process the chromium tanning waste. Filtration of this mixture is very complicated because it is case of mixture filtration with compressible cake. Successful process strongly depends on mathematical describing of filtration, calculating optimal values of pressure difference, specific resistant of filtration cake and temperature maintenance which is connected with viscosity change. The mathematic model of filtration with compressible cake we verified in laboratory conditions on special filtration device developed on our department.

  4. The Development and Testing of a Prototype Mini-Baghouse to Control the Release of Respirable Crystalline Silica from Sand Movers

    Science.gov (United States)

    Alexander, Barbara M.; Esswein, Eric J.; Gressel, Michael G.; Kratzer, Jerry L.; Feng, H. Amy; King, Bradley; Miller, Arthur L.; Cauda, Emanuele

    2016-01-01

    Inhalation of respirable crystalline silica (RCS) is a significant risk to worker health during well completions operations (which include hydraulic fracturing) at conventional and unconventional oil and gas extraction sites. RCS is generated by pneumatic transfer of quartz-containing sand during hydraulic fracturing operations. National Institute for Occupational Safety and Health (NIOSH) researchers identified concentrations of RCS at hydraulic fracturing sites that exceed 10 times the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) and up to 50 times the NIOSH Recommended Exposure Limit (REL). NIOSH research identified at least seven point sources of dust release at contemporary oil and gas extraction sites where RCS aerosols were generated. NIOSH researchers recommend the use of engineering controls wherever they can be implemented to limit the RCS released. A control developed to address one of the largest sources of RCS aerosol generation is the NIOSH mini-baghouse assembly, mounted on the thief hatches on top of the sand mover. This manuscript details the results of a trial of the NIOSH mini-baghouse at a sand mine in Arkansas, November 18 – 21, 2013. During the trial, area air samples were collected at 12 locations on and around a sand mover with and without the mini-baghouse control installed. Analytical results for respirable dust and RCS indicate the use of the mini-baghouse effectively reduced both respirable dust and RCS downwind of the thief hatches. Reduction of airborne respirable dust ranged from 85% to 98%; reductions in airborne RCS ranged from 79% to 99%. A bulk sample of dust collected by the baghouse assembly showed the likely presence of freshly fractured quartz, a particularly hazardous form of RCS. Planned future design enhancements will increase the performance and durability of the mini-baghouse, including an improved bag clamp mechanism and upgraded filter fabric with a modified air-to-cloth ratio

  5. The development and testing of a prototype mini-baghouse to control the release of respirable crystalline silica from sand movers.

    Science.gov (United States)

    Alexander, Barbara M; Esswein, Eric J; Gressel, Michael G; Kratzer, Jerry L; Feng, H Amy; King, Bradley; Miller, Arthur L; Cauda, Emanuele

    2016-08-01

    Inhalation of respirable crystalline silica (RCS) is a significant risk to worker health during well completions operations (which include hydraulic fracturing) at conventional and unconventional oil and gas extraction sites. RCS is generated by pneumatic transfer of quartz-containing sand during hydraulic fracturing operations. National Institute for Occupational Safety and Health (NIOSH) researchers identified concentrations of RCS at hydraulic fracturing sites that exceed 10 times the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL) and up to 50 times the NIOSH Recommended Exposure Limit (REL). NIOSH research identified at least seven point sources of dust release at contemporary oil and gas extraction sites where RCS aerosols were generated.  NIOSH researchers recommend the use of engineering controls wherever they can be implemented to limit the RCS released. A control developed to address one of the largest sources of RCS aerosol generation is the NIOSH mini-baghouse assembly, mounted on the thief hatches on top of the sand mover. This article details the results of a trial of the NIOSH mini-baghouse at a sand mine in Arkansas from November 18-21, 2013.  During the trial, area air samples were collected at 12 locations on and around a sand mover with and without the mini-baghouse control installed. Analytical results for respirable dust and RCS indicate the use of the mini-baghouse effectively reduced both respirable dust and RCS downwind of the thief hatches. Reduction of airborne respirable dust ranged from 85-98%; reductions in airborne RCS ranged from 79-99%. A bulk sample of dust collected by the baghouse assembly showed the likely presence of freshly fractured quartz, a particularly hazardous form of RCS.  Planned future design enhancements will increase the performance and durability of the mini-baghouse, including an improved bag clamp mechanism and upgraded filter fabric with a modified air-to-cloth ratio

  6. Some observations on air filtration

    NARCIS (Netherlands)

    Kluyver, A.J.; Visser, J.

    1950-01-01

    1. A method has been developed for testing the filtration efficiency of some filter materials. For each of the materials investigated — cotton wool, stillite and carbon — a suitable filter has been devised. 2. The filtered air was analyzed as to its germ content with the aid of a set of 3 capillary

  7. Filtration combustion: Smoldering and SHS

    Science.gov (United States)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  8. Filtration Understanding: FY10 Testing Results and Filtration Model Update

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P.; Shimskey, Rick W.

    2011-04-04

    This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.

  9. Time resolved measurements of pulse intensity, filter movement and regeneration during cleaning of baghouse filters

    OpenAIRE

    Sobich, S.; Kasper, G; Meyer, J

    2016-01-01

    The “cleaning intensity” of a filter bag during pressure-pulse regeneration is a determining factor for both the stability of the filtration cycle and the emission level. On the other hand, the relationship between the shape of a pressure pulse signal, the resulting movement of the filter media (i.e. position, velocity, acceleration), and the removal of dust from the surface and/or interstices of the filter media is still not fully understood. An experiment has been designed around a coupon f...

  10. Filtration characteristics in membrane bioreactors

    OpenAIRE

    Evenblij, H.

    2006-01-01

    Causes of and remedies for membrane fouling in Membrane Bioreactors for wastewater treatment are only poorly understood and described in scientific literature. A Filtration Characterisation Installation and a measurement protocol were developed with the aim of a) unequivocally determination and quantification of the filterability of an activated sludge and b) carrying out short term experiments at labscale to determine foulants and/or fouling propensity determining factors. The installation w...

  11. Cake creep during filtration of flocculated manure

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    that the discrepancy between the filtration theory and the observed filtration behaviour is due to a time-dependent collapse of the formed cake (creep). This can also explain the observed behaviour when flocculated manure is filtered. The filtration data can be simulated if cake creep is adopted in the filtration...... model. The calculation shows that the specific filter-cake resistance increases by a factor of 3 during the filtration. Thus, the impact of cake creep is significant when organic materials such as manure are filtered....

  12. Water Filtration Using Plant Xylem

    Science.gov (United States)

    Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

    2014-01-01

    Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings. PMID:24587134

  13. Evaluation of the plasma quality after filtration

    Directory of Open Access Journals (Sweden)

    M Mahmoodian Shooshtari

    2010-06-01

    Full Text Available "n  "n "nBackground and the purpose of the study: The quality of some of the human plasma derived drugs such as coagulation factor VIII and coagulation factor IX which can be used for the treatment of hemophilia A and B, depends on their activity which may be affected by filtration. In this study the quality of plasma with respect to coagulation factors FVII, FVIII, FIX, FV, FXI, Fibrinogen, antithrombin III, anti-plasmin and antitrypsin activities obtained after plasma filtration with CPD (citrate-phosphate-dextrose using integral filter was evaluated. "nMethods:Sixty units of plasma were individually separated from whole blood by centrifugation and immediately filtered by integral filter system. Specific plasma filtration was carried out between 4 and 20 hrs after blood donation. Before filtration, 60 units of non filtered fresh plasmas were kept as control. "nCoagulation factors were determined by one-stage clotting assay in an automated system. Antithrombin III activity was determined by immunochrom assay in an automated system. Activity of anti-plasmin was determined by Berichrom α2 - antiplasmin and antitrypsin activity was assayed with human neutrophil elastase. "n  "nResults:The activity of coagulation factors FVIII, FIX, Fibrinogen, FV, and FXI, were not affected by filtration, in all experiments. Filtration only caused negligible change in FVII activity. Antithrombin III, anti-plasmin and antitrypsin activities were not influenced by filtration. Non-filtrated and filtrated plasma values were not significantly different (P> 0.05. Conclusions:Plasma filtration dose not result in a measurable impairment of coagulation factors and inhibitors. Although a little changes in FVII activity was observed after filtration, but these filtration-dependent changes apparently have no impact on the therapeutic quality of whole blood- filtered fresh plasma for transfusion.

  14. Side Stream Filtration for Cooling Towers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  15. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    Science.gov (United States)

    Jamal, Sondus; Chang, Sheng; Zhou, Hongde

    2014-01-01

    This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP) increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA. PMID:25007243

  16. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    Directory of Open Access Journals (Sweden)

    Sondus Jamal

    2014-07-01

    Full Text Available This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA.

  17. Demonstration of creep during filtration

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Bugge, Thomas Vistisen; Kirchheiner, Anders Løvenbalk

    root of time. Even more clearly it is demonstrated by plotting the liquid pressure at the cake piston interface v.s. the relative deformation (to be shown). The phenomenon of a secondary consolidation processes is in short called creep. Provided that the secondary consolidation rate is of the same...... magnitude as the primary consolidation (defined by the hydraulic retardation), the creep phenomenon may occur during filtration. This will lead to Ruth's plots characterized by a concave with two (more or less) distinct slopes. The slopes are defined by the relationship between the porosity...... and the hydraulic resistance before and after the collapse of the solids structure. This has been observed and modelled for dewatering experiments with activated sludge. It will be argued that although a strong resemblance between blinding and creep exists, these two effects may readily be distinguished by virtue...

  18. Tangential Flow Filtration of Hemoglobin

    Science.gov (United States)

    Sun, Guoyong; Harris, David R.

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells (bRBCs and hRBCs, respectively) via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P50), and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (α) and beta (β) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the α and β globin chains agreed well with the calculated theoretical mass of the α-and β-globin chains. Taken together, our results demonstrate that HPLC grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers (HBOCs). PMID:19224583

  19. Evaluation of Side Stream Filtration Technology at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Brian K.

    2014-08-01

    This technology evaluation was performed by Pacific Northwest National Laboratory and Oak Ridge National Laboratory on behalf of the Federal Energy Management Program. The objective was to quantify the benefits side stream filtration provides to a cooling tower system. The evaluation assessed the performance of an existing side stream filtration system at a cooling tower system at Oak Ridge National Laboratory’s Spallation Neutron Source research facility. This location was selected because it offered the opportunity for a side-by-side comparison of a system featuring side stream filtration and an unfiltered system.

  20. THE FILTRATION PROPERTIES OF POROUS DIATOMITE

    African Journals Online (AJOL)

    measure the properties in geometry similar to the application as much as possible. Diatomite is a siliceous material that is commonly used in the manufacture of filter elements for domestic and industrial filtration. This paper presents a study of flow of water. (filtration) through diatomaceous filters, under low and high intensity ...

  1. PDF-based heterogeneous multiscale filtration model.

    Science.gov (United States)

    Gong, Jian; Rutland, Christopher J

    2015-04-21

    Motivated by modeling of gasoline particulate filters (GPFs), a probability density function (PDF) based heterogeneous multiscale filtration (HMF) model is developed to calculate filtration efficiency of clean particulate filters. A new methodology based on statistical theory and classic filtration theory is developed in the HMF model. Based on the analysis of experimental porosimetry data, a pore size probability density function is introduced to represent heterogeneity and multiscale characteristics of the porous wall. The filtration efficiency of a filter can be calculated as the sum of the contributions of individual collectors. The resulting HMF model overcomes the limitations of classic mean filtration models which rely on tuning of the mean collector size. Sensitivity analysis shows that the HMF model recovers the classical mean model when the pore size variance is very small. The HMF model is validated by fundamental filtration experimental data from different scales of filter samples. The model shows a good agreement with experimental data at various operating conditions. The effects of the microstructure of filters on filtration efficiency as well as the most penetrating particle size are correctly predicted by the model.

  2. On divisorial filtrations associated with Newton diagrams

    OpenAIRE

    Ebeling, Wolfgang; Gusein-Zade, Sabir M.

    2010-01-01

    We consider divisorial filtration on the rings of functions on hypersurface singularities associated with Newton diagrams and their analogues for plane curve singularities. We compute the multi-variable Poincar\\'e series for the latter ones.

  3. Determination of glomerular filtration rate with radionuclide ...

    African Journals Online (AJOL)

    Determination of glomerular filtration rate with radionuclide renography and direct urinary activity quantitation. A. C. Otto, P. H. Pretorius, M. Dunn, M. G. Nel, A. van Aswegen, J. Marais, M. G. Lotter ...

  4. A High Capacity Advanced Fuel Filtration System

    National Research Council Canada - National Science Library

    Jen, Chang-Wei

    2000-01-01

    .... The filtration effect of the candidate filter media on the FSII contained in JP-8 has also been investigated. The test results lay a good foundation for the development of a prototype in Phase II.

  5. Portable Hybrid Powered Water Filtration Device

    National Research Council Canada - National Science Library

    Maria Lourdes V. Balansay; Mary Rose Q. Añonuevo; Rexzel M. Cuenca; Ricmart V. Garbin

    2015-01-01

    .... The design of the portable hybrid powered water filtration device shows that the project has more advanced features such as portability and the power supply used such as photovoltaic module solar...

  6. Pig manure treatment and purification by filtration.

    Science.gov (United States)

    Makara, A; Kowalski, Z

    2015-09-15

    This study aimed to develop a new, complex pig manure treatment and filtration process. The final scheme, called the AMAK process, comprised the following successive steps: mineralization with mineral acids, alkalization with lime milk, superphosphate addition, a second alkalization, thermal treatment, and pressure filtration. The proposed method produced a filtrate with 95%, 80%, and 96% reductions in chemical oxygen demand, nitrogen content, and phosphorus content, respectively. An advantage of the proposed method was that it incorporated a crystalline phase into the solid organic part of the manure, which enabled high filtration rates (>1000 kg m(-2) h(-1)) and efficient separation. The process also eliminated odor emissions from the filtrate and sediment. The treated filtrate could be used to irrigate crops or it could be further treated in conventional biological wastewater treatment plants. The sediment could be used for producing mineral-organic fertilizer. The AMAK process is inexpensive, and it requires low investment costs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Properties of the filtrate from treatment of pig manure by filtration method

    Directory of Open Access Journals (Sweden)

    Makara Agnieszka

    2017-02-01

    Full Text Available This paper presents properties of filtrate obtained from pig manure using the AMAK treatment process, which includes the mineralization of macro- and microfertilizer components by the hydrolyzing of organic matter into forms that are bioavailable to plants. Filtration produced two products, sediment and filtrate. The quality of the filtrate allowed for its use as a substitute of water to irrigate crops. Concentrations of heavy metals are very low and therefore the quality of the filtrate fully complies with European standard concerning fertilizers. The used mineralization process practically eliminated odors from the filtrate. The reduction of specific odor emission by 99.1-99.5% in samples taken from above the filtrate, respectively compared to the odor concentration found in samples taken from above raw pig manure. Sediment could be used as raw material for production of mineral-organic fertilizer. Filtrate and filtration sediments analyses show that the majority of nitrogen and other fertilizing compounds included in raw pig manure remains in sediment.

  8. Low-density lipoprotein apheresis by membrane differential filtration (cascade filtration) via arteriovenous fistula performed in children with familial hypercholesterolemia.

    Science.gov (United States)

    Gülle, Saniye; Bak, Mustafa; Serdaroglu, Erkin; Can, Demet; Karabay, Ozalp

    2010-02-01

    Membrane differential filtration (cascade filtration) is an apheresis technique by which atherogenic lipoproteins can be eliminated from plasma on the basis of particle size. In this study, we aim to discuss the efficacy of low-density lipoprotein (LDL) apheresis performed by providing alternative vascular routes in two siblings with familial hypercholesterolemia who did not respond to medical treatment and diet. Of the two siblings, one was nine years old and the other one was three-and-a-half years old. Of the total of 78 apheresis processes performed, 24 were done via a permanent subclavian catheter, 36 were done via a subsequently provided arteriovenous fistula, and 18 were done via an arteriovenous graft. We observed a mean reduction in the plasma levels of total cholesterol (61.6%), LDL cholesterol (65.5%), and high-density lipoprotein cholesterol (38.6%). We noted that cascade filtration apheresis was effective in decreasing the LDL cholesterol in plasma, and no serious complications were noted. The success of the apheresis program depends on well-functioning blood access. An arteriovenous fistula may be the best route for the long-term treatment of familial hypercholesterolemia, which requires complication-free apheresis treatments.

  9. Enhanced performance of crumb rubber filtration for ballast water treatment.

    Science.gov (United States)

    Tang, Zhijian; Butkus, Michael A; Xie, Yuefeng F

    2009-03-01

    Waste-tire-derived crumb rubber was utilized as filter media to develop an efficient filter for ballast water treatment. In this study, the effects of coagulation, pressure filtration and dual-media (gravity) filtration on the performance of the crumb rubber filtration were investigated. The removal efficiencies of turbidity, phytoplankton and zooplankton, and head loss development were monitored during the filtration process. The addition of a coagulant enhanced the removal efficiencies of all targeted matter, but resulted in substantial increase of head loss. Pressure filtration increased filtration rates to 220 m(3)h(-1)m(-2) for 8-h operation and improved the zooplankton removal. Dual-media (crumb rubber/sand) gravity filtration also improved the removal efficiencies of phytoplankton and zooplankton over mono-media gravity crumb rubber filtration. However, these filtration techniques alone did not meet the criteria for removing indigenous organisms from ballast water. A combination of filtration and disinfection is suggested for future studies.

  10. Cake formation and growth in cake filtration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.S.; Hsiau, S.S. [National Central University, Chungli (Taiwan)

    2009-06-15

    In this study we develop an experimental method to help understand the formation and growth of dust cakes. An on-line pressure-displacement measurement system is developed to measure the thickness of the dust cakes. A higher filtration superficial velocity resulted in a higher degree of compaction in the dust cakes and thus a higher specific cake resistance, hence a better collection efficiency could be achieved. The empirical equations for cake solidosity, and specific cake resistance as a function of the filtration superficial velocity are derived. We find that the cake filter is influenced by the cake thickness and the filtration superficial velocity. The results of this study can be applied to granular bed filters for the removal of dust particulates in advanced coal-fired power systems.

  11. Salt disposition alternatives filtration at SRTC

    Energy Technology Data Exchange (ETDEWEB)

    Walker, B. W.; Hobbs, D.

    2000-01-27

    Several of the prospective salt disposition alternative technologies require a monosodium titanate (MST) contact to remove strontium and actinides from inorganic salt solution feedstock. This feedstock also contains sludge solids from waste removal operations and may contain defoamers added in the evaporator systems. Filtration is required to remove the sludge and MST solids before sending the salt solution for further processing. This report describes testing performed using the Parallel Theological Experimental Filter (PREF). The PREF contains two single tube Mott sintered metal crossflow filters. For this test one filter was isolated so that the maximum velocities could be achieved. Previous studies showed slurries of MST and sludge in the presence of sodium tetraphenylborate (NaTPB) were filterable since the NaTPB slurry formed a filter cake which aided in removing the smaller MST and sludge particles. Some of the salt disposition alternative technologies do not use NaTPB raising the question of how effective crossflow filtration is with a feed stream containing only sludge and MST. Variables investigated included axial velocity, transmembrane pressure, defoamer effects, and solids concentration (MST and sludge). Details of the tests are outlined in the technical report WSRC-RP-98-O0691. Key conclusions from this study are: (1) Severe fouling of the Mott sintered metal filter did not occur with any of the solutions filtered. (2) The highest fluxes, in the range of .46 to 1.02 gpm/f{sup 2}, were obtained when salt solution decanted from settled solids was fed to the filter. These fluxes would achieve 92 to 204 gpm filtrate production for the current ITP filters. The filtrate fluxes were close to the flux of 0.42 gpm/f{sup 2} reported for In Tank Precipitation Salt Solution by Morrisey. (3) For the range of solids loading studied, the filter flux ranged from .04 to .17 gpm/f{sup 2} which would result in a filtrate production rate of 9 to 31 gpm for the current HP

  12. Upflow gravel filtration for multiple uses

    NARCIS (Netherlands)

    Sanchez Torres, L.D.

    2016-01-01

    The use of upflow gravel filtration (UFG) is relevant for water supply systems in rural areas and small towns in Colombia, because water quality from surface sources is changing due to the deterioration of watersheds caused by deforestation, erosion, and the discharge of untreated wastewater. These

  13. Plasma discharge self-cleaning filtration system

    Science.gov (United States)

    Cho, Young I.; Fridman, Alexander; Gutsol, Alexander F.; Yang, Yong

    2014-07-22

    The present invention is directed to a novel method for cleaning a filter surface using a plasma discharge self-cleaning filtration system. The method involves utilizing plasma discharges to induce short electric pulses of nanoseconds duration at high voltages. These electrical pulses generate strong Shockwaves that disintegrate and dislodge particulate matter located on the surface of the filter.

  14. Filtration of engineered nanoparticles using porous membranes

    NARCIS (Netherlands)

    Trzaskus, Krzystof

    2016-01-01

    The research presented in this thesis aims at providing a better understanding of the fundamental aspects responsible for nanoparticle removal and fouling development during filtration of engineered nanoparticles. The emphasis is put on the role of interparticle interactions in the feed solution,

  15. Determination of glomerular filtration rate with radionuclide ...

    African Journals Online (AJOL)

    r J Clin acin- armacal itidine n in man. Determination of glomerular filtration rate with radionuclide renography and direct urinary activity quantitation. A. C. 000, P. H. Pretorius, M. Dunn, M. G. Net,. A. van Aswegen, J. Marais, M. G. Latter. Objective. The direct urinary activity quantitation method is quick (approximately 40 ...

  16. Advances in hot gas filtration technology

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.

    The past decade has seen the introduction of new filter media specifically designed for 'hot-gas' filtration. These media are available as woven or knitted fabrics and as non-wovens, i.e. needled felts. Needlefelted fabrics have proven so highly successful in the dedusting of hot gases that they are widely used nowadays in this new and necessary technology. Hot-gas filtration offers advantages in, for example, the saving or recycling of energy, the elimination of the cooling process, and the short-circuiting of process steps. This paper gives a survey of the types of textile fibres available for hot-gas filtration from the more recently developed organic fibres to refractory fibres. It describes, compares and contrasts their salient properties and lists the uses to which they may be put. It concentrates on such fibres which are generally referred to as 'high performance materials', since they are expected to provide satisfactory performance under extreme conditions of temperature, chemical environment and mechanical stress. It touches on filtration theory governing the collection mechanism. 9 refs., 7 figs., 3 tabs.

  17. OPTIMIZATION OF THE PROCESS OF DRYING THE FILTRATE DISTILLERY DREGS

    Directory of Open Access Journals (Sweden)

    A. A. Shevtsov

    2013-01-01

    Full Text Available The interactions of various factors affecting the process of drying the filtrate distillery dregs are investigated. Rational conditions for the process of drying the filtrate distillery dregs in a spray dryer are obtained.

  18. Internal filtration, filtration fraction, and blood flow resistance in high- and low-flux dialyzers.

    Science.gov (United States)

    Schneditz, Daniel; Zierler, Edda; Vanholder, Raymond; Eloot, Sunny

    2014-01-01

    It was the aim to examine the fluid flow in blood and dialysate compartments of highly permeable hollow fiber dialyzers where internal filtration contributes to solute removal but where excessive filtration bears a risk of cell activation and damage. Flow characteristics of high- (HF) and low-flux (LF) dialyzers were studied in lab-bench experiments using whole bovine blood. Measurements obtained under different operating conditions and under zero net ultrafiltration were compared to theoretical calculations obtained from a mathematical model. Experimental resistances in the blood compartment were within ±2% of those calculated from the model when dialysate was used as a test fluid. With whole blood, the experimental resistances in the blood compartment were only 81.8 ± 2.8% and 83.7 ± 4.3% of those calculated for the LF and HF dialyzer, respectively. Surprisingly, measured blood flow resistance slightly but significantly decreased with increasing flow rate (p filtration fraction, while overall internal filtration increased. The increase in internal filtration when increasing blood flow is associated with a beneficial reduction in internal filtration fraction. Concerns of increased hemoconcentration when increasing blood flow therefore appear to be unwarranted.

  19. Retention of Acholeplasma laidlawii by sterile filtration membranes: effect of cultivation medium and filtration temperature.

    Science.gov (United States)

    Helling, Alexander; König, Hannes; Seiler, Felix; Berkholz, Ralph; Thom, Volkmar; Polakovic, Milan

    2018-01-17

    This experimental study compares cell size, zeta potential and the ability to penetrate tailor-made size exclusion membrane filters of mycoplasma A. laidlawii cultivated in five different cultivation media. The influence of relevant filtration process parameters, in particular transmembrane pressure and filtration temperature, on their respective retention was tested. The impact of the filtration temperature was further evaluated for the Gram-negative bacteria species Brevundimonas diminuta, the Gram-positive bacteria species Staphylococcus epidermidis, the Pseudomonas phage PP7 and the mycoplasma species M. orale. The findings were correlated to the different mechanical properties of the particles, especially also with respect to the different bacterial cell envelopes found in those species. This study suggests, that mycoplasma, surrounded by a flexible lipid bilayer, are significantly susceptible to changes in temperature, altering the stiffness of the cell envelope. Mycoplasma retention could thus be increased significantly by a decreased filtration temperature. In contrast, Gram-negative and Gram-positive bacteria species, with a cell wall containing a cross-linked peptidoglycan layer, as well as bacteriophages PP7 exhibiting a rigid protein capsid, did not show a temperature dependent retention within the applied filtration temperatures between 2 and 35 °C. The trends of the retention of A. laidlawii with increasing temperature and transmembrane pressure were independent of cultivation media. Data obtained with mycoplasma M. orale suggest that the trend of mycoplasma retention at different filtration temperatures is also independent of the membrane pore size and thus retention level. Copyright © 2018, Parenteral Drug Association.

  20. Comparison of phytoremediation and filtration in remediation Of ...

    African Journals Online (AJOL)

    An experimental work was carried out on contaminated waters using filtration and phytoremediation methods to determine the most appropriate remediation method. Filtration method was by passing Arsenic acid of 100.0 mg/L concentrations through four different geo-materials (marble, activated charcoal, filtration carbon ...

  1. Cytotoxity of cell free filtrates of campylobacter jejuni isolated in ...

    African Journals Online (AJOL)

    Culture filtrates of Campylobacter jejuni strains isolated from clinical specimens in Lagos Nigeria were tested for toxic activity. Two out of five filtrates tested manifested cytopathic effect on BHK cells. The effects were mainly cytotoxic and cytotonic. Toxic activity of C. jejuni filtrates was much lower than toxic activity elicited by ...

  2. Origins of the poor filtration characteristics of wheat starch hydrolysates

    NARCIS (Netherlands)

    Matser, A.M.; Steeneken, P.A.M.

    1998-01-01

    The effects of wheat starch components on the filtration characteristics of wheat starch hydrolysates were investigated with a model-based approach. The filtration rate was not affected by the removal of the pentosans or by altering the conformation of the protein. On the other hand, the filtration

  3. 21 CFR 177.2910 - Ultra-filtration membranes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultra-filtration membranes. 177.2910 Section 177... Components of Articles Intended for Repeated Use § 177.2910 Ultra-filtration membranes. Ultra-filtration membranes identified in paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this section may be safely used in...

  4. Enlargement of filtration with finance in view

    CERN Document Server

    Aksamit, Anna

    2017-01-01

    This volume presents classical results of the theory of enlargement of filtration. The focus is on the behavior of martingales with respect to the enlarged filtration and related objects. The study is conducted in various contexts including immersion, progressive enlargement with a random time and initial enlargement with a random variable.  The aim of this book is to collect the main mathematical results (with proofs) previously spread among numerous papers, great part of which is only available in French. Many examples and applications to finance, in particular to credit risk modelling and the study of asymmetric information, are provided to illustrate the theory. A detailed summary of further connections and applications is given in bibliographic notes which enables to deepen study of the topic.  This book fills a gap in the literature and serves as a guide for graduate students and researchers interested in the role of information in financial mathematics and in econometric science. A basic knowledge of...

  5. Ultrasonic filtration of industrial chemical solutions

    Science.gov (United States)

    Cosma, T.

    1974-01-01

    The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

  6. Nanoparticles filtration by leaked fibrous filters

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, Guillaume; Calle-Chazelet, Sandrine; Thomas, Dominique; Appert-Collin, Jean-Christophe [Nancy-Universite/LSGC/CNRS - 1 rue Grandville - BP 20451 - F-54001 Nancy Cedex (France)], E-mail: sandrine.calle@ensic.inpl-nancy.fr; Bemer, Denis [INRS - Avenue de Bourgogne - F-54501 Vandoeuvre les Nancy Cedex (France)

    2009-05-01

    The aim of this work is first to measured nanoparticles penetration through three different fiberglass filters intentionally-pierced with calibrated needles at different filtration velocity. Then a semi-empirical model based on the air flow resistances of the new and perforated filter media and on the mechanism of Brownian diffusion for the collection of ultrafine particles by the media enables to well predict the efficiency observed for all tested operating conditions. Results show that the increase of particles penetration is all the more important that the pinhole is large and that the particle diameter is low. Another result is that the filtration efficiency of the new filter media controlled the penetration. A high efficiency filter with a high resistance to air flow will be more damaged than a low efficiency filter when being perforated.

  7. Air filtration and indoor air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2006-01-01

    Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

  8. Direct filtration of Biesbosch water and Algae and water treatment in the Netherlands : 3rd Direct Filtration Seminar

    NARCIS (Netherlands)

    Petrusevski, B.; Vlaski, A.; Van Breemen, A.N.; Alaerts, G.J.

    1993-01-01

    This presentation summarises basic information on direct filtration, and demonstrates the main research findings, related to the performance of simple in-line direct filtration. The results reported are part of a comprehensive ongoing research programm "Direct filtration of Biesbosch water"

  9. Solar silicon refining; Inclusions, settling, filtration, wetting

    OpenAIRE

    Ciftja, Arjan

    2009-01-01

    The main objective of the present work is the removal of inclusions from silicon scrap and metallurgical grade silicon. To reach this goal, two various routes are investigated. First, settling of SiC particles from molten silicon followed by directional solidification is reported in this thesis. Then, removal of SiC and Si3N4 inclusions in silicon scrap by filtration with foam filters and wettabilities of silicon on graphite materials are studied. To supply the increasing needs of the...

  10. Processing of let-down by filtration

    Energy Technology Data Exchange (ETDEWEB)

    Pfirrmann, T.

    1942-10-19

    Filtration used for complete separation of the solids in the let-down process is discussed. The conditions necessary for a filterable let-down were summarized as follows. Pasting with a middle oil rich in aromatics, limitation of the hydrogen consumption and consequent hydrogenation (producing a largely bituminous hydrogenation product), a low throughput at low and medium pressures, and a heavy oil return as low as possible. This applied to pressure up to about 450 atm. If the pressure was increased to 700 atm the operating conditions could be extended. The middle oil pasting remained the same, but the hydrogenation temperature could be increased to 470 to 480/sup 0/C and the throughput increased to 1.0 ton/m/sup 3/ converter vol/hr. The hydrogen consumption could also be increased, so that, besides the bituminous hydrogenation product, a greater proportion of liquid products, gasoline and middle oil, was produced. This operating method at 700 atm, therefore, represented an intermediate stage between hydrogenating extraction and normal hydrogenation, whose let-down was still practically unfilterable. (The filtration itself was fitted to the characteristics of the filter feed). The best type of filter was found to be a thin layer filter with a layer of filter aid of porous material, which was automatically removed with the filter residue. The filter residue contained 35 to 40% oil, largely easily distilled middle oil. The advantages of let-down processing by filtration, compared to the formerly usual methods of centrifuging and low-temperature carbonization, were mentioned. It was to be expected that with the future development of this operation the proportion of oil could be considerably increased, so that filtration might also be applied to fuel oil, or gasoline and middle oil, respectively, even with a modified operating method.

  11. Portable Hybrid Powered Water Filtration Device

    OpenAIRE

    Maria Lourdes V. Balansay; Mary Rose Q. Añonuevo; Rexzel M. Cuenca; Ricmart V. Garbin

    2015-01-01

    The existing water filtration device has features that can be developed to be more useful and functional during emergency situations. The project’s development has been aided by following provisions in PEC, NEC, NEMA and Philippine National Standard for Safe Drinking Water provide standards for the construction of the project. These standards protect both the prototype and the user. These also served as guide for the maintenance of every component. The design of the portable hybri...

  12. Portable Hybrid Powered Water Filtration Device

    Directory of Open Access Journals (Sweden)

    Maria Lourdes V. Balansay

    2015-08-01

    Full Text Available The existing water filtration device has features that can be developed to be more useful and functional during emergency situations. The project’s development has been aided by following provisions in PEC, NEC, NEMA and Philippine National Standard for Safe Drinking Water provide standards for the construction of the project. These standards protect both the prototype and the user. These also served as guide for the maintenance of every component. The design of the portable hybrid powered water filtration device shows that the project has more advanced features such as portability and the power supply used such as photovoltaic module solar cells and manually operated generator. This also shows its effectiveness and reliability based on the results of discharging test, water quality test and water production test. Based on analysis of the overall financial aspects, the machine can be profitable and the amount of revenue and operating cost will increase as years pass. Using the proper machine/ tools and methods of fabrication helps in easy assembly of the project. The materials and components used are cost effective and efficient. The best time for charging the battery using solar panel is 9:00 am onwards while the hand crank generator is too slow because the generated current is little. The water filtration device is very efficient regarding the operating hours and water production. The machine may have a great effect to society and economy in generation of clean available water at less cost.

  13. Prohibitin Signaling at the Kidney Filtration Barrier.

    Science.gov (United States)

    Ising, Christina; Brinkkoetter, Paul T

    2017-01-01

    The kidney filtration barrier consists of three well-defined anatomic layers comprising a fenestrated endothelium, the glomerular basement membrane (GBM) and glomerular epithelial cells, the podocytes. Podocytes are post-mitotic and terminally differentiated cells with primary and secondary processes. The latter are connected by a unique cell-cell contact, the slit diaphragm. Podocytes maintain the GBM and seal the kidney filtration barrier to prevent the onset of proteinuria. Loss of prohibitin-1/2 (PHB1/2) in podocytes results not only in a disturbed mitochondrial structure but also in an increased insulin/IGF-1 signaling leading to mTOR activation and a detrimental metabolic switch. As a consequence, PHB-knockout podocytes develop proteinuria and glomerulosclerosis and eventually loss of renal function. In addition, experimental evidence suggests that PHB1/2 confer additional, extra-mitochondrial functions in podocytes as they localize to the slit diaphragm and thereby stabilize the unique intercellular contact between podocytes required to maintain an effective filtration barrier.

  14. Soluble manganese removal by porous media filtration.

    Science.gov (United States)

    Kim, J; Jung, S

    2008-12-01

    Filtration experiments were conducted to investigate soluble manganese removal in granular media filtration; sand, manganese oxide coated sand (MOCS), sand + MOCS (1:1) and granular activated carbon (GAC) were used as filter media. Manganese removal, manganese oxide accumulation, turbidity removal, and regeneration of MOCS under various conditions were examined. Soluble manganese removal by the MOCS column was rapid and efficient; most of the removal happened at the top (e.g. 5 cm) of the filter. When filter influent with an average manganese concentration of 0.204 mg l(-1) was fed through the filter columns, the sand + MOCS and MOCS columns removed 98.9% and 99.2% of manganese, respectively. However, manganese removal in sand and the GAC columns was not significant during the initial stage of filtration, but after eight months of filter run they could remove 99% and 35% of manganese, respectively. It was revealed that partial replacement of sand with MOCS showed comparable manganese removal to that of the MOCS filter media.

  15. Lack of carbon air filtration impacts early embryo development.

    Science.gov (United States)

    Munch, Erika M; Sparks, Amy E; Duran, Hakan E; Van Voorhis, Bradley J

    2015-07-01

    To assess human fertilization and preimplantation embryo development in the presence and in the absence of carbon filtration This is a retrospective cohort analysis of fresh, controlled ovarian hyperstimulation cycles as well as previously cryopreserved pronuclear stage embryo transfer cycles in a single IVF center. Embryo development and cycle-based outcomes were compared among three groups: 1) when carbon filtration was present, 2) when carbon filtration was absent, and 3) when carbon filtration had been restored. A total of 524 fresh cycles and 156 cryopreserved embryo cycles were analyzed. Fertilization, cleavage, and blastocyst conversion rates for fresh cycles all declined during the period of absent carbon filtration and recovered after the restoration of carbon filtration. Cryopreserved embryos that were thawed and cultured during the period of absent filtration did not have changes in cleavage or blastocyst conversion rates compared to periods where carbon filtration was present. Clinical pregnancy and live birth rates were unchanged among the three time periods. The absence of carbon filtration in an IVF laboratory air handler is associated with poor fertilization and early embryo development for fresh cycles. Because development of previously frozen pronuclear stage embryos was unaffected, the lack of carbon filtration may preferentially affect embryos in the peri-fertilization period. Carbon filtration is an integral part to a successful human in-vitro fertilization laboratory.

  16. Nanofiber filter media for air filtration

    Science.gov (United States)

    Raghavan, Bharath Kumar

    Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200--300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling. The particle loading on a microfibrous filter were studied for air filtration tests. The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers

  17. Filtration Combustion in Smoldering and SHS

    Science.gov (United States)

    Matkowsky, Bernard J.

    2001-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS , a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to ensure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS nevertheless, the two applications have much in common so that what is learned fit make application can be used to advantage in the other. In porous

  18. Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

    2009-03-02

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan (Barnes and Voke 2006). The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Hanford Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP RPP WTP 467 (Fiskum et al. 2007), eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan. • Characterizing the homogenized sample groups. • Performing parametric leaching testing on each group for compounds of interest. • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on a filtration/leaching test performed using two of the eight waste composite samples. The sample groups examined in this report were the plutonium-uranium extraction (PUREX) cladding waste sludge (Group 3, or CWP) and reduction-oxidation (REDOX) cladding waste sludge (Group 4, or CWR). Both the Group 3 and 4 waste composites were anticipated to be high in gibbsite, thus requiring caustic leaching. WTP RPT 167 (Snow et al. 2008) describes the homogenization, characterization, and parametric leaching activities before benchtop filtration/leaching testing of these two waste groups. Characterization and initial parametric data in that report were used to plan a single filtration/leaching test using a blend of both wastes. The test focused on filtration testing of the waste and caustic leaching for aluminum, in the form

  19. Gas filtration in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, J. (Univ. de Castilla-La Mancha, Ciudad Real (Spain)); Guardiola, J.; Romero, A. (Univ. de Alcala de Henares, Madrid (Spain))

    1992-12-01

    A systematic experimental study of aerosol filtration in a binary fluidized bed of dielectric material is carried out. Measurements of the collection efficiency when such parameters as gas velocity, bed height, collecting mixture, and column diameter are varied over a wide range have been made. Experimental evidence is given to show that charges generated naturally by triboelectrification of the bed dielectric particles can considerably increase the efficiency of such beds. Furthermore, it is demonstrated that a proper choice of the fluidized mixture can significantly improve the performance of such filters.

  20. Advanced Emissions Control Development Program

    Energy Technology Data Exchange (ETDEWEB)

    A.P.Evans; K.E. Redinger; M.J. Holmes

    1998-04-01

    The objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. Ideally, the project aim is to effectively control air toxic emissions through the use of conventional flue gas cleanup equipment such as electrostatic precipitators (ESPS), fabric filters (baghouse), and wet flue gas desulfurization. Development work to date has concentrated on the capture of mercury, other trace metals, fine particulate and hydrogen chloride. Following the construction and evaluation of a representative air toxics test facility in Phase I, Phase II focused on the evaluation of mercury and several other air toxics emissions. The AECDP is jointly funded by the United States Department of Energy's Federal Energy Technology Center (DOE), the Ohio Coal Development Office within the Ohio Department of Development (oCDO), and Babcock& Wilcox-a McDermott company (B&W).

  1. Dynamic optimization of a dead-end filtration trajectory: non-ideal cake filtration

    NARCIS (Netherlands)

    Blankert, B.; Kattenbelt, C.; Betlem, Bernardus H.L.; Roffel, B.

    2007-01-01

    A control strategy aimed at minimizing energy consumption is formulated for non-ideal dead-end cake filtration with an inside-out hollow fiber ultrafiltration membrane system. The non-ideal behavior was assumed to originate from cake compression, non-linear cake resistance and a variable pump

  2. Dynamic optimization of a dead-end filtration trajectory : Non-ideal cake filtration

    NARCIS (Netherlands)

    Blankert, Bastiaan; Kattenbelt, Carolien; Betlem, Ben H.L.; Roffel, Brian

    2007-01-01

    A control strategy aimed at minimizing energy consumption is formulated for non-ideal dead-end cake filtration with an inside-out hollow fiber ultrafiltration membrane system. The non-ideal behavior was assumed to originate from cake compression, non-linear cake resistance and a variable pump

  3. Dynamic optimization of a dead-end filtration trajectory : Blocking filtration laws

    NARCIS (Netherlands)

    Blankert, Bastiaan; Betlem, Ben H.L.; Roffel, Brian

    2006-01-01

    An operating model for dead-end membrane filtration is proposed based on the well-known blocking laws. The resulting model contains three parameters representing, the operating strategy, the fouling mechanism and the fouling potential of the feed. The optimal control strategy is determined by

  4. Dynamic optimization of a dead-end filtration trajectory: Blocking filtration laws

    NARCIS (Netherlands)

    Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.

    2006-01-01

    An operating model for dead-end membrane filtration is proposed based on the well-known blocking laws. The resulting model contains three parameters representing, the operating strategy, the fouling mechanism and the fouling potential of the feed. The optimal control strategy is determined by

  5. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    NARCIS (Netherlands)

    Sanchez, L.D.; Marin, L.M.; Visscher, J.T.; Rietveld, L.C.

    2012-01-01

    This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF) in a multi-stage filtration (MSF) plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It

  6. A study of dynamic filtration; Um estudo sobre filtracao dinamica

    Energy Technology Data Exchange (ETDEWEB)

    Girao, Joaquim Helder S. [PETROBRAS, Natal, RN (Brazil). Distrito de Perfuracao da Bacia Potiguar. Div. de Tecnicas de Perfuracao

    1989-12-31

    The problems that cause cost increase such as: formation damage and borehole swelling or caving lead us to study the filtration of the liquid part of formation drilling fluid. With the aim of comparing static and dynamic filtration rates, we developed a modest dynamic filtration equipment, consisting of a modified API filter, connected to reservoir by means of a positive injection pump. We carried out various tests, and the results were set in charts and tables. Through these, it is possible to notice how the static and dynamic filtration curves come apart for a same pressure value. We also evaluated the effects of circulation speed, starch concentration and counter pressure. This paper does not include calculations or mathematical models accounting for filtrate invasion radii, but it demonstrates, for example, that cleaning circulation will cause lower filtration rates at lower flows. (author) 5 refs., 11 figs., 14 tabs.

  7. The effect of filter cake viscoelasticity on filtration

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard

    Wastewater is usually treated biologically, and a by-product from this treatment is waste-activated sludge with high water content. Sludge is therefore often filtrated to reduce the volume for handling and disposal, and to minimise the water content before incineration of the sludge. However......, it is difficult to use the existing mathematical filtration models to simulate and optimise the filtration process. Activated sludge as well as synthetic model particles has been filtrated in this project. The study shows that compression of the formed filter cake is a time dependent process, and not only...... a function of pressure as assumed when using the conventional models. Moreover, it is shown how the existing filtration models can be modified and the filtration process for activated sludge simulated....

  8. Vision-related quality of life following glaucoma filtration surgery.

    Science.gov (United States)

    Hirooka, Kazuyuki; Nitta, Eri; Ukegawa, Kaori; Tsujikawa, Akitaka

    2017-05-12

    To evaluate vision-related quality of life (VR-QOL) following glaucoma filtration surgery. A total of 103 glaucoma patients scheduled to undergo glaucoma filtration surgery. Prior to and at three months after glaucoma filtration surgery, trabeculectomy or EX-PRESS, all patients completed the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25). A total of 48 patients underwent combined cataract and filtration surgery. The clinical data collected pre- and postoperatively included best-corrected visual acuity (BCVA) and intraocular pressure (IOP). The IOP decreased significantly from 19.0 ± 8.1 mmHg to 9.7 ± 3.9 mmHg (P glaucoma filtration surgery by itself did not decrease the VR-QOL in glaucoma patients, there was significant improvement in the VR-QOL after the patients underwent combined cataract and glaucoma filtration surgery.

  9. Filtration Systems Design for Universal Oils in Agricultural Tractors

    Directory of Open Access Journals (Sweden)

    R. Majdan

    2017-12-01

    Full Text Available Three filtration systems using the tractor hydraulic circuit were proposed and verified during the tractors operation. Using the tractor-implement hydraulic system and filter body with accessories the universally useful filtration systems were designed. The designed filtration systems are the second stage of universal oil filtration whereas the first stage is the standard tractor filter. The decrease in the content of iron reached the values 25.53 %, 32.95 % and 41.55 % and the average decrease in oil contamination characterized by average value of decrease in content of iron, copper and silicium reached values 24.3 %, 24.7 % and 35.53 % in dependence on the filtration system and an oil contamination level. The decrease in contamination level verified the ability of designed filtration systems for agricultural tractors.

  10. Update on the glomerular filtration barrier

    Science.gov (United States)

    Jarad, George; Miner, Jeffrey H.

    2010-01-01

    Purpose of the review The nephrology community lacks a unified view of protein sieving through the glomerular capillary wall (GCW). The GCW consists of three distinct but closely interacting layers: the fenestrated endothelium, with its glycocalyx; the podocytes, with their interdigitated foot processes and slit diaphragms; and the intervening glomerular basement membrane (GBM). Proteinuria is associated with abnormalities in any one layer, suggesting that each contributes to the glomerular filtration barrier (GFB). Proteinuria can also be induced in the context of a normal GCW. Here we review some classic studies as well as some newer concepts and present competing hypotheses about the GFB. Recent findings Two almost forgotten concepts have recently emerged. One group has challenged the exquisite selectivity of the GFB to albumin and suggested that proteinuria is the result of abnormal tubular uptake. There has also been a reemphasis on diffusion through the GBM as the driving force behind macromolecular filtration. New evidence suggests that the endothelial glycocalyx is an important charge-selective barrier. Summary We suggest viewing the GFB as a dynamic rather than as a rigid barrier, requiring three healthy layers and a hemodynamic steady state. Multiple challenges to studying the endothelium, the tubular handling of albumin, and the role of hemodynamic forces will require new tools, new hypotheses, and open minds. PMID:19374010

  11. Electrospinning of nanofibers for filtration media

    Science.gov (United States)

    Park, Hyoungjun

    Since particulate impurity is regarded as the primary cause of lung diseases, purification of air has been a crucial issue. Filtration is the most conventional method to obtain clean air, whereby particulate matter is collected on a fibrous media. The use of fibrous filters is prevalent because of their high filtration efficiency and low pressure drop. Fibrous filters were fabricated via the electrospinning process which can be used to produce continuous submicron-diameter sized fibers. Polyacrylonitrile (PAN) nanofibers with a mean fiber diameter of 224 nm were electrospun to form fibermats. Filtration tests on fibermats of PAN were conducted to confirm that filters of thinner fibers result in higher collection efficiencies and lower pressure drops than that of thicker fibers as predicted by the theoretical filtration mechanism. Results showed that electrospun PAN nanofibermats had a superior quality factor of 0.067+/-0 compared to 0.031+/-0.001 by the current state-of-the-art microfiber-based high particulate air (HEPA) filtration media. The verified theory implies that nanofibermats of other types of materials could also be considered as promising filtration media since filtration performance is independent of the material used. As materials for advanced next-generation filtration media, ceramics are favored over polymeric materials due to their robustness against environmental factors such as ultraviolet rays, abrasive particles, and high temperature all of which degrade and damage the fibrous structure. Amidst various ceramic materials, the anatase phase of TiO2 was selected due to its mechanical property and versatility as a photocatalyst and microwave-absorbing material. Anatase TiO2 fibers were fabricated by electrospinning followed by heat treatment at 500°C for 3 hours. However, early precipitation or gelation of the organic solvent-based TiO2 sol posed a practical challenge in the sample preparation. In order to enhance stability of the precursor sol, a

  12. Tailoring Supramolecular Nanofibers for Air Filtration Applications.

    Science.gov (United States)

    Weiss, Daniel; Skrybeck, Dominik; Misslitz, Holger; Nardini, David; Kern, Alexander; Kreger, Klaus; Schmidt, Hans-Werner

    2016-06-15

    The demand of new materials and processes for nanofiber fabrication to enhance the performance of air filters is steadily increasing. Typical approaches to obtain nanofibers are based on top-down processes such as melt blowing, centrifugal spinning, and electrospinning of polymer materials. However, fabrication of polymer nanofibers is limited with respect to either a sufficiently high throughput or the smallest achievable fiber diameter. This study reports comprehensively on a fast and simple bottom-up process to prepare supramolecular nanofibers in situ inside viscose/polyester microfiber nonwovens. Here, selected small molecules of the materials class of 1,3,5-benzenetrisamides are employed. The microfiber-nanofiber composites exhibit a homogeneous nanofiber distribution and morphology throughout the entire nonwoven scaffold. Small changes in molecular structure and processing solvent have a strong influence on the final nanofiber diameter and diameter distribution and, consequently, on the filtration performance. Choosing proper processing conditions, microfiber-nanofiber composites with surprisingly high filtration efficiencies of particulate matter are obtained. In addition, the microfiber-nanofiber composite integrity at elevated temperatures was determined and revealed that the morphology of supramolecular nanofibers is maintained compared to that of the utilized polymer nonwoven.

  13. Length filtration of the separable states

    Science.gov (United States)

    Chen, Lin; Doković, Dragomir Ž.

    2016-11-01

    We investigate the separable states ρ of an arbitrary multi-partite quantum system with Hilbert space H of dimension d. The length L(ρ) of ρ is defined as the smallest number of pure product states having ρ as their mixture. The length filtration of the set of separable states, S , is the increasing chain ∅ ⊊S1‧⊆S2‧⊆⋯, where Si‧={ρ ∈S :L (ρ )≤i }. We define the maximum length, Lmax=maxρ ∈S L (ρ ), critical length, Lcrit, and yet another special length, Lc, which was defined by a simple formula in one of our previous papers. The critical length indicates the first term in the length filtration whose dimension is equal to Dim S . We show that in general d≤Lc≤Lcrit≤Lmax≤d2. We conjecture that the equality Lcrit=Lc holds for all finite-dimensional multi-partite quantum systems. Our main result is that Lcrit=Lc for the bipartite systems having a single qubit as one of the parties. This is accomplished by computing the rank of the Jacobian matrix of a suitable map having S as its range.

  14. Update on the glomerular filtration barrier.

    Science.gov (United States)

    Jarad, George; Miner, Jeffrey H

    2009-05-01

    The nephrology community lacks a unified view of protein sieving through the glomerular capillary wall. The glomerular capillary wall consists of three distinct but closely interacting layers: the fenestrated endothelium, with its glycocalyx; the podocytes, with their interdigitated foot processes and slit diaphragms; and the intervening glomerular basement membrane. Proteinuria is associated with abnormalities in any one layer, suggesting that each contributes to the glomerular filtration barrier (GFB). Proteinuria can also be induced in the context of a normal glomerular capillary wall. Here, we review some classic studies as well as some newer concepts and present competing hypotheses about the GFB. Two almost forgotten concepts have recently emerged. One group has challenged the exquisite selectivity of the GFB to albumin and suggested that proteinuria is the result of abnormal tubular uptake. There has also been a reemphasis on diffusion through the glomerular basement membrane as the driving force behind macromolecular filtration. New evidence suggests that the endothelial glycocalyx is an important charge-selective barrier. We suggest viewing the GFB as a dynamic rather than as a rigid barrier, requiring three healthy layers and a hemodynamic steady state. Multiple challenges to studying the endothelium, the tubular handling of albumin, and the role of hemodynamic forces will require new tools, new hypotheses, and open minds.

  15. Silica incorporated membrane for wastewater based filtration

    Science.gov (United States)

    Fernandes, C. S.; Bilad, M. R.; Nordin, N. A. H. M.

    2017-10-01

    Membrane technology has long been applied for waste water treatment industries due to its numerous advantages compared to other conventional processes. However, the biggest challenge in pressure driven membrane process is membrane fouling. Fouling decreases the productivity and efficiency of the filtration, reduces the lifespan of the membrane and reduces the overall efficiency of water treatment processes. In this study, a novel membrane material is developed for water filtration. The developed membrane incorporates silica nanoparticles mainly to improve its structural properties. Membranes with different loadings of silica nanoparticles were applied in this study. The result shows an increase in clean water permeability and filterability of the membrane for treating activated sludge, microalgae solution, secondary effluent and raw sewage as feed. Adding silica into the membrane matrix does not significantly alter contact angle and membrane pore size. We believe that silica acts as an effective pore forming agent that increases the number of pores without significantly altering the pore sizes. A higher number of small pores on the surface of the membrane could reduce membrane fouling because of a low specific loading imposed to individual pores.

  16. Filtration kinetics of chitosan separation by electrofiltration.

    Science.gov (United States)

    Gözke, Gözde; Kirschhöfer, Frank; Heissler, Stefan; Trutnau, Mirko; Brenner-Weiss, Gerald; Ondruschka, Jelka; Obst, Ursula; Posten, Clemens

    2012-02-01

    Downstream processing of chitosan requires several technological steps that contribute to the total production costs. Precipitation and especially evaporation are energy-consuming processes, resulting in higher costs and limiting industrial scale production. This study investigated the filtration kinetics of chitosan derived from cell walls of fungi and from exoskeletons of arthropods by electrofiltration, an alternative method, thus reducing the downstream processing steps and costs. Experiments with different voltages and pressures were conducted in order to demonstrate the effect of both parameters on filtration kinetics. The concentration of the biopolymer was obtained by the average factor of 40 by applying an electric field of 4 V/mm and pressure of 4 bars. A series of analytical experiments demonstrated the lack of structural and functional changes in chitosan molecules after electrofiltration. These results, combined with the reduction of energy and processing time, define the investigated method as a promising downstream step in the chitosan production technology. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. METC CFD simulations of hot gas filtration

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, T.J.

    1995-06-01

    Computational Fluid Dynamic (CFD) simulations of the fluid/particle flow in several hot gas filtration vessels will be presented. These simulations have been useful in designing filtration vessels and in diagnosing problems with filter operation. The simulations were performed using the commercial code FLUENT and the METC-developed code MFIX. Simulations of the initial configuration of the Karhula facility indicated that the dirty gas flow over the filter assemblage was very non-uniform. The force of the dirty gas inlet flow was inducing a large circulation pattern that caused flow around the candles to be in opposite directions on opposite sides of the vessel. By introducing a system of baffles, a more uniform flow pattern was developed. This modification may have contributed to the success of the project. Several simulations of configurations proposed by Industrial Filter and Pump were performed, varying the position of the inlet. A detailed resolution of the geometry of the candles allowed determination of the flow between the individual candles. Recent simulations in support of the METC/CeraMem Cooperative Research and Development Agreement have analyzed the flow in the vessel during the cleaning back-pulse. Visualization of experiments at the CeraMem cold-flow facility provided confidence in the use of CFD. Extensive simulations were then performed to assist in the design of the hot test facility being built by Ahlstrom/Pyropower. These tests are intended to demonstrate the CeraMem technology.

  18. Granular media filtration: old process, new thoughts.

    Science.gov (United States)

    Lawler, D F; Nason, J A

    2006-01-01

    The design of granular media filters has evolved over many years so that modern filters have larger media sizes and higher filtration velocities than in earlier times. The fundamental understanding of filtration has also improved over time, with current models that account reasonably for all characteristics of the media, the suspension and the filter operation. The methodology for design, however, has not kept pace with these improvements; current designs are based on pilot plants, past experience, or a simple guideline (the ratio of the bed depth to media grain size). We propose that design should be based universally on a characteristic removal length, with the provision of a bed depth that is some multiple of that characteristic length. This characteristic removal length is calculated using the most recent (and most complete) fundamental model and is based on the particle size with the minimum removal efficiency in a filter. The multiple of the characteristic length that yields the required bed depth has been calibrated to existing, successful filters.

  19. Vibrating membrane filtration as improved technology for microalgae dewatering

    OpenAIRE

    Torras, C.; Salvadó, J.; Clavero, E.; C. Nurra

    2014-01-01

    10.1016/j.biortech.2014.01.115 The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean ...

  20. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    C. Jean Bustard; Charles Lindsey; Paul Brignac

    2006-05-01

    This document provides a summary of the full-scale demonstration efforts involved in the project ''Field Test Program for Long-Term Operation of a COHPAC{reg_sign} System for Removing Mercury from Coal-Fired Flue Gas''. The project took place at Alabama Power's Plant Gaston Unit 3 and involved the injection of sorbent between an existing particulate collector (hot-side electrostatic precipitators) and a COHPAC{reg_sign} fabric filter (baghouse) downstream. Although the COHPAC{reg_sign} baghouse was designed originally for polishing the flue gas, when activated carbon injection was added, the test was actually evaluating the EPRI TOXECON{reg_sign} configuration. The results from the baseline tests with no carbon injection showed that the cleaning frequency in the COHPAC{reg_sign} unit was much higher than expected, and was above the target maximum cleaning frequency of 1.5 pulses/bag/hour (p/b/h), which was used during the Phase I test in 2001. There were times when the baghouse was cleaning continuously at 4.4 p/b/h. In the 2001 tests, there was virtually no mercury removal at baseline conditions. In this second round of tests, mercury removal varied between 0 and 90%, and was dependent on inlet mass loading. There was a much higher amount of ash exiting the electrostatic precipitators (ESP), creating an inlet loading greater than the design conditions for the COHPAC{reg_sign} baghouse. Tests were performed to try to determine the cause of the high ash loading. The LOI of the ash in the 2001 baseline tests was 11%, while the second baseline tests showed an LOI of 17.4%. The LOI is an indication of the carbon content in the ash, which can affect the native mercury uptake, and can also adversely affect the performance of ESPs, allowing more ash particles to escape the unit. To overcome this, an injection scheme was implemented that balanced the need to decrease carbon injection during times when inlet loading to the baghouse was high and

  1. Filtration in the Use of Individual Water Purification Devices

    National Research Council Canada - National Science Library

    Lundquist, Arthur; Clarke, Steven; Bettin, William

    2006-01-01

    .... Understanding the ability of filtration to reduce disease-causing microorganisms in water is important in protecting Soldiers, who are considering using this technology, from acute health threats...

  2. Filtration of ultrafine metallic particles in industry.

    Science.gov (United States)

    Bémer, D; Morele, Y; Régnier, R

    2015-01-01

    Thermal metal spraying, metal cutting and arc welding processes generate large quantities of ultrafine particles that cause the irreversible clogging of industrial filters. The aim of the study performed was to identify the causes of the clogging of cartridge filters and investigate other paths for cleaning them. This study required the development of a test bench capable of reproducing a thermal spraying process to test the performances of different filtration techniques. This test instrument first, permitted the precise characterization of the aerosol generated by the process and, second, defined the clogging and cleaning conditions for filters. Several parameters were tested: the type of filter, online and off-line cleaning, pre-coating, cleaning by jets of high-speed compressed air via a probe.

  3. Membraneless water filtration using CO2

    Science.gov (United States)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick B.; Stone, Howard A.

    2017-05-01

    Water purification technologies such as microfiltration/ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles. Due to the large diffusion potential generated by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits low energy consumption, three orders of magnitude lower than conventional microfiltration/ultrafiltration processes, and is essentially free from fouling.

  4. Glomerular filtration rate in endurance athletes.

    Science.gov (United States)

    Lippi, Giuseppe; Banfi, Giuseppe; Salvagno, Gian Luca; Franchini, Massimo; Guidi, Gian Cesare

    2008-05-01

    The interpretation of biochemical testing in sportsmen requires caution. Although creatinine-based estimates of glomerular filtration rate (GFR) overcome some shortcomings of serum creatinine, there is scarce information on their use in endurance athletes. We evaluated GFR, estimated by the recommended Modification of Diet in Renal Disease (MDRD) equation in athletes. Seventy-six professional male cyclists, 71 amateur male cyclists, and 65 healthy sedentary matched controls were included in the study. The mean serum creatinine level was significantly higher in the sedentary subjects (81 microM) than in amateur (75 microM; P intensity of daily physical exercise, but not the body mass index, was inversely associated with serum creatinine and positively associated with the estimated GFR. The MDRD equation should be used with caution in athletes, and it should consider intensity and type of physical exercise.

  5. Filtration and Leach Testing for REDOX Sludge and S-Saltcake Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Geeting, John GH; Hallen, Richard T.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Snow, Lanee A.; Swoboda, Robert G.

    2009-02-20

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.( ) The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP-RPP-WTP-467, eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste-testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan • Characterizing the homogenized sample groups • Performing parametric leaching testing on each group for compounds of interest • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on filtration/leaching tests performed on two of the eight waste composite samples and follow-on parametric tests to support aluminum leaching results from those tests.

  6. Evaluation of a Combined Cyclone and Gas Filtration System for Particulate Removal in the Gasification Process

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, Jeffrey J. [Phillips66 Company, West Terre Haute, IN (United States)

    2010-04-30

    cyclonefiltration hybrid unit in the E-Gas (TM) gasification process. These reductions would help to keep the E-Gas (TM) technology competitive among other coal-fired power generation technologies. The Wabash combined cyclone and gas filtration slipstream test program was developed to provide design information, equipment specification and process control parameters of a hybrid cyclone and candle filter particulate removal system in the E-Gas (TM) gasification process that would provide the optimum performance and reliability for future commercial use. The test program objectives were as follows: 1. Evaluate the use of various cyclone materials of construction; 2. Establish the optimal cyclone efficiency that provides stable long term gas filter operation; 3. Determine the particle size distribution of the char separated by both the cyclone and candle filters. This will provide insight into cyclone efficiency and potential future plant design; 4. Determine the optimum filter media size requirements for the cyclone-filtration hybrid unit; 5. Determine the appropriate char transfer rates for both the cyclone and filtration portions of the hybrid unit; 6. Develop operating procedures for the cyclone-filtration hybrid unit; and, 7. Compare the installed capital cost of a scaled-up commercial cyclone-filtration hybrid unit to the current gas filtration design without a cyclone unit, such as currently exists at the Wabash facility.

  7. glomerular filtration rate profiles in paediatric patients on cancer

    African Journals Online (AJOL)

    2013-05-28

    May 28, 2013 ... The glomerular filtration rate (GFR) is widely accepted as the best index of renal function in patients. Chemotherapy is the mainstay of treatment in the paediatric oncology unit at the Kenyatta National Hospital. Objectives: To determine the glomerular filtration rate profiles of paediatric oncology patients and ...

  8. Noisy signal filtration using complex wavelet basis sets

    Science.gov (United States)

    Yaseen, A. S.; Pavlova, O. N.; Pavlov, A. N.

    2017-07-01

    Methods of noisy signal filtration using a discrete wavelet transform (DWT) with real basis sets of the Daubechies family are compared to methods employing a double-density dual-tree complex wavelet transform (DDCWT) with excess (nonorthonormalized) basis sets. Recommendations concerning the choice of filter parameters for minimization of the error of noisy signal filtration are formulated.

  9. A mathematical model for the leukocyte filtration process

    NARCIS (Netherlands)

    Bruil, A.; Bruil, Anton; Beugeling, T.; Beugeling, Tom; Feijen, Jan

    1995-01-01

    Leukocyte filters are applied clinically to remove leukocytes from blood. In order to optimize leukocyte filters, a mathematical model to describe the leukocyte filtration process was developed by modification of a general theoretical model for depth filtration. The model presented here can be used

  10. Dynamic optimization of dead-end membrane filtration

    NARCIS (Netherlands)

    Blankert, B.; Betlem, Bernardus H.L.; Roffel, B.; Marquardt, Wolfgang; Pantelides, Costas

    2006-01-01

    An operating strategy aimed at minimizing the energy consumption during the filtration phase of dead-end membrane filtration has been formulated. A method allowing fast calculation of trajectories is used to allow incorporation in a hierarchical optimization scheme. The optimal trajectory can be

  11. Vibrating membrane filtration as improved technology for microalgae dewatering.

    Science.gov (United States)

    Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

    2014-04-01

    The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly

  13. Important clinical and laboratory correlates of glomerular filtration ...

    African Journals Online (AJOL)

    Background: Renal impairment is routinely assessed using the estimated glomerular filtration rate (eGFR) and it may be helpful to obtain certain clinical or laboratory markers, which show relationship with glomerular filtration rate (GFR) in sickle cell disease (SCD). Aim: To assess the relationship between important clinical ...

  14. Parthenium management by cultural filtrates of phytopathogenic fungi.

    Science.gov (United States)

    Javaid, Arshad; Adrees, Huma

    2009-01-01

    In the present study, herbicidal activity of culture filtrates of nine phytopathogenic fungi, namely, Alternaria alternata (Fr.) Keissl., Drechslera australiensis (Bugnicourt) Subramanian & Jain, Drechslera hawaiiensis (Curtis and Cooke) Shoemaker, Drechslera biseptata (Saccardo & Roumeguere) Richardson & Fraser., Drechslera rostrata (Drechsler) Ricardson & Fraser, Fusarium oxysporum (Massey) Synd. & Hans., Fusarium solani (Martius) Saccardo., Monilia stophila (Montagne) and Cladosporium sp. (Grey) de Hoff, was evaluated against parthenium weed (Parthenium hysterophorus L.). In laboratory bioassays, the effect of original (100%) as well as lower concentrations (75, 50 and 25%) of these cultural filtrates was studied on germination and early seedling growth of parthenium. Cultural filtrates of different concentrations of A. alternata, Cladosporium sp. and D. rostrata significantly suppressed the germination of parthenium seeds by 70-90, 13-73 and 27-50%, respectively. Cultural filtrates of these fungi also exhibited pronounced adverse effects on the seedling root and shoot growth. Among other fungal species, cultural filtrates of D. australiensis, D. hawaiiensis, F. oxysprium and F. solani significantly reduced the root and shoot length of parthenium seedlings. Foliar spray bioassay was performed using cultural filtrates of three fungal species, namely A. alternata, F. solani and D. rostrata. In this bioassay, three sprays of fungal cultural filtrates, with 4 day intervals each, were carried out on 1 and 2 week-old pot-grown seedlings of parthenium. Cultural filtrates of all the three fungal species markedly suppressed root and shoot growth of parthenium weed.

  15. Life Support Filtration System Trade Study for Deep Space Missions

    Science.gov (United States)

    Agui, Juan H.; Perry, Jay L.

    2017-01-01

    The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.

  16. Performance of multistage filtration using different filter media ...

    African Journals Online (AJOL)

    This study was aimed at introducing multistage filtration (MSF) (a combination of slow-sand filtration (SSF) and pretreatment system - horizontal flow roughing filter (HRF)) as an alternative water treatment technology to the conventional one. A pilot- plant study was undertaken to achieve this goal. Evaluating the MSF ...

  17. Purification of contaminated water by filtration through porous glass

    Science.gov (United States)

    Wydeven, T.; Leban, M. I.

    1972-01-01

    Method for purifying water that is contaminated with mineral salts and soluble organic compounds is described. Method consists of high pressure filtration of contaminated water through stabilized porous glass membranes. Procedure for conducting filtration is described. Types of materials by percentage amounts removed from the water are identified.

  18. Effects of processing methods on sorghum wort filtration | Igyor ...

    African Journals Online (AJOL)

    Brewing parameters measured were filtration rate, specific gravity, viscosity, reducing sugars, hot water extract, soluble extract level, fermentable extract level, and fermentability level. Results revealed that though the sorghum worts had faster filtration rate than barley in infusion at 65°C, other brewing parameters were all ...

  19. Simulation of impaction filtration by a porous filter

    NARCIS (Netherlands)

    Ghazaryan, L.; Lopez Penha, D.J.; Geurts, Bernardus J.; Stolz, S.; Stolz, S.; Winkelmann, C.; Vafai, K.

    2010-01-01

    We present a new numerical approach for estimating filtration through porous media from first principles. We numerically simulate particle motion as arises in a carrier gas flow. The filtration we look at occurs due to impaction of particles with obstructing surfaces that are contained in the solid

  20. STORMWATER TREATMENT AT CRITICAL AREAS: EVALUATION OF FILTRATION MEDIA

    Science.gov (United States)

    Past research has identified urban runoff as a major contributor to the degradation of urban streams and rivers. Filtration, especially "slow" filtration, is of interest for stormwater runoff treatment because filters will work on intermittent flows without significant loss of ca...

  1. Application of granular media filtration in wastewater reclamation and reuse.

    Science.gov (United States)

    Hamoda, M F; Al-Ghusain, I; Al-Jasem, D M

    2004-01-01

    Laboratory experiments were conducted at room temperature (20-25 degrees C) using four identical filter columns made of Plexiglas, each of 1 m height and 15 cm internal diameter, packed with granular media of 70 cm depth. Each filter was operated at a constant filtration rate, thus four rates were tested in the range of 2-15 m(3) m(-2) d(-1). Mono-media (sand) and dual-media (sand and anthracite) were tested and three types of municipal wastewaters, namely raw, primary and secondary-treated effluents were applied. The results obtained indicate that considerable improvements in effluent quality could be attained by tertiary sand filtration. Removal of solids, organics and bacteria was not significantly affected by the increase in filtration rate from 2 to 15 m(3) m(-2) d(-1). The highest removal efficiency was obtained at low filtration rate of 2 m(3) m(-2) d(-1), but higher filtration rates achieved acceptable removal efficiencies and provided effluents of good quality to satisfy the irrigation water quality standards. Since the conventional sand filters in wastewater treatment plants operate at a rate in the range of 2-5 m(3) m(-2) d(-1), utilization of high rate filtration is advantageous and would result in significant cost savings. However, with high filtration rates the filters require more frequent backwashing. Dual-media filters achieved 50% reductions in BOD suggesting that filtration could be used to treat primary effluents in emergency cases.

  2. Some aspects of applying nanostructured materials in air filtration, water filtration and electrical engineering

    Science.gov (United States)

    Kimmer, Dusan; Vincent, Ivo; Lovecka, Lenka; Kazda, Tomas; Giurg, Adam; Skorvan, Ondrej

    2017-05-01

    Nanostructures prepared from nanofibres and nanostructured composites prepared from nanofibres and fillers are gradually becoming increasingly demanded materials for applications in various industrial branches connected with catalysis, environment protection (air filtration, waste water treatment, sound absorption), in biological engineering, electronics (battery separators, electrode materials), etc. Selected applications of these materials prepared in the company SPUR a.s. are summed up in the following presentation.

  3. Harvesting microalgal biomass using crossflow membrane filtration: critical flux, filtration performance, and fouling characterization.

    Science.gov (United States)

    Elcik, Harun; Cakmakci, Mehmet

    2017-06-01

    The purpose of this study was to investigate the efficient harvesting of microalgal biomass through crossflow membrane filtration. The microalgal biomass harvesting experiments were performed using one microfiltration membrane (pore size: 0.2 µm, made from polyvinylidene fluoride) and three ultrafiltration membranes (molecular weight cut-off: 150, 50, and 30 kDa, made from polyethersulfone, hydrophilic polyethersulfone, and regenerated cellulose, respectively). Initially, to minimize membrane fouling caused by microalgal cells, experiments with the objective of determining the critical flux were performed. Based on the critical flux calculations, the best performing membrane was confirmed to be the UH050 membrane, produced from hydrophilic polyethersulfone material. Furthermore, we also evaluated the effect of transmembrane pressure (TMP) and crossflow velocity (CFV) on filtration flux. It was observed that membrane fouling was affected not only by the membrane characteristics, but also by the TMP and CFV. In all the membranes, it was observed that increasing CFV was associated with increasing filtration flux, independent of the TMP.

  4. Simplification of vacuole structure during plant cell death triggered by culture filtrates of Erwinia carotovora.

    Science.gov (United States)

    Hirakawa, Yumi; Nomura, Toshihisa; Hasezawa, Seiichiro; Higaki, Takumi

    2015-01-01

    Vacuoles are suggested to play crucial roles in plant defense-related cell death. During programmed cell death, previous live cell imaging studies have observed vacuoles to become simpler in structure and have implicated this simplification as a prelude to the vacuole's rupture and consequent lysis of the plasma membrane. Here, we examined dynamics of the vacuole in cell cycle-synchronized tobacco BY-2 (Nicotiana tabacum L. cv. Bright Yellow 2) cells during cell death induced by application of culture filtrates of Erwinia carotovora. The filtrate induced death in about 90% of the cells by 24 h. Prior to cell death, vacuole shape simplified and endoplasmic actin filaments disassembled; however, the vacuoles did not rupture until after plasma membrane integrity was lost. Instead of facilitating rupture, the simplification of vacuole structure might play a role in the retrieval of membrane components needed for defense-related cell death. © 2014 Institute of Botany, Chinese Academy of Sciences.

  5. Efficient filtration system for paraffin-catalyst slurry separation

    Directory of Open Access Journals (Sweden)

    Khodagholi Mohammad Ali

    2013-01-01

    Full Text Available The filtration efficiency for separating liquid paraffin (or water from a slurry consisting of 25 weight% spherical alumina in a Slurry Bubble Column Reactor (SBCR comprised of a cylindrical tube of 10 cm diameter and 150 cm length was studied. Various differential pressures (ΔP were applied to two separate tubular sintered metal stainless steel filter elements with nominal pore size of 4 and 16μm. The experimental results disclosed that the rate of filtrations increased on applying higher differential pressure to the filter element. Albeit this phenomenon is limited to moderate ΔPs and for ΔP more than 1 bar is neither harmful nor helpful. The highest filtration rates at ΔPs higher than 1 bar were 170 and 248 ml/minute for 4 and 16μm respectively. Using water as the liquid in slurry the rate of filtration enhanced to 4 folds, and this issue reveals impact of viscosity on filtration efficiency clearly. In all situations, the total amount of particles present in the filtrate part never exceeded a few parts per million (ppm. The statistical analysis of the SEM image of the filtrate indicated that by applying higher pressure difference to the filter element the frequency percent of larger particle size increases. The operation of filter cake removing was performed with back flashing of 300 ml of clean liquid with pressures of 3-5 bar of N2 gas.

  6. Filtration application from recycled expanded polystyrene.

    Science.gov (United States)

    Shin, C

    2006-10-01

    Water-in-oil emulsion with drop size less than 100 mum is difficult to separate. Coalescence filtration is economical and effective for separation of secondary dispersions. Coalescence performance depends on flow rate, bed depth, fiber surface properties, and drop size. The amount of surface area of the fibers directly affects the efficiency. A new recycling method was investigated in the previous work in which polystyrene (PS) sub-mum fibers were electro-spun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. The experimental results in this work show that adding nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media but also increases the pressure drop. An optimum in the performance occurs (significant increase in efficiency with minimal increase in pressure drop) with the addition of about 4% by mass of 500 nm diameter PS nanofibers to glass fibers for the filters.

  7. Crosslinked polytriazole membranes for organophilic filtration

    KAUST Repository

    Chisca, Stefan

    2016-12-30

    We report the preparation of crosslinked membranes for organophilic filtration, by reacting a new polytriazole with free OH groups, using non-toxic poly (ethylene glycol) diglycidyl ether (PEGDE). The OH-functionalized polymer was obtained by converting the oxadiazole to triazole rings with high yield (98%). The maximum degree of crosslinking is achieved after 6 h of reaction. The crosslinked polytriazole membranes are stable in a wide range of organic solvents and show high creep recovery, indicating the robustness of crosslinked membranes. The influence of different casting solutions and different crosslinking time on the membrane morphology and membrane performance was investigated. The membranes performance was studied in dimethylformamide (DMF) and (tetrahydrofuran) THF. We achieved a permeance for THF of 49 L m−2 h−1 bar−1 for membranes with molecular weight cut off (MWCO) of 7 kg mol−1 and a permeance for THF of 17.5 L m−2 h−1 bar−1 for membranes with MWCO of 3 kg mol−1. Our data indicate that by using the new polytriazole is possible to adjust the pore dimensions of the membranes to have a MWCO, which covers ultra- and nanofiltration range.

  8. Filtration of submicrometer particles by pelagic tunicates.

    Science.gov (United States)

    Sutherland, Kelly R; Madin, Laurence P; Stocker, Roman

    2010-08-24

    Salps are common in oceanic waters and have higher per-individual filtration rates than any other zooplankton filter feeder. Although salps are centimeters in length, feeding via particle capture occurs on a fine, mucous mesh (fiber diameter d approximately 0.1 microm) at low velocity (U = 1.6 +/- 0.6 cmxs(-1), mean +/- SD) and is thus a low Reynolds-number (Re approximately 10(-3)) process. In contrast to the current view that particle encounter is dictated by simple sieving of particles larger than the mesh spacing, a low-Re mathematical model of encounter rates by the salp feeding apparatus for realistic oceanic particle-size distributions shows that submicron particles, due to their higher abundances, are encountered at higher rates (particles per time) than larger particles. Data from feeding experiments with 0.5-, 1-, and 3-microm diameter polystyrene spheres corroborate these findings. Although particles larger than 1 microm (e.g., flagellates, small diatoms) represent a larger carbon pool, smaller particles in the 0.1- to 1-microm range (e.g., bacteria, Prochlorococcus) may be more quickly digestible because they present more surface area, and we find that particles smaller than the mesh size (1.4 microm) can fully satisfy salp energetic needs. Furthermore, by packaging submicrometer particles into rapidly sinking fecal pellets, pelagic tunicates can substantially change particle-size spectra and increase downward fluxes in the ocean.

  9. Fibrosis of the Choroid Plexus Filtration Membrane

    Science.gov (United States)

    Parratt, John D. E.; Kirwan, Paul D.

    2016-01-01

    We report a previously undescribed inflammatory lesion consisting of deposition of activated complement (C3d and C9neo) in association with major histocompatibility complex type II (MHC2)-positive activated microglia in choroid plexus villi exhibiting classical fibrous thickening of the pericapillary filtration membrane. The proportion of villi affected ranged from 5% to 90% in 56 adult subjects with diseases of the CNS and 11 subjects with no preexisting disease of the CNS. In 3 of the 4 children studied, 2% or less of examined villi showed stromal thickening, complement deposition, and the presence of MHC2-positive microglia; in adults, the proportion of villi affected increased with age. Other features of the lesion included loss of capillaries and failure by macrophages to clear extracellular particulate electron-dense material by clathrin-mediated phagocytosis. This choroid plexus lesion may relate pathogenetically to age-related macular degeneration and to Alzheimer disease, 2 other conditions with no known risk factors other than increasing age. All 3 conditions are characterized by the presence of damaged capillaries, inflammatory extracellular aggregates of mixed molecular composition and defective clearance of the deposits by macrophages. PMID:27444353

  10. Estimating Glomerular Filtration Rate in Older People

    Directory of Open Access Journals (Sweden)

    Sabrina Garasto

    2014-01-01

    Full Text Available We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting.

  11. Swine wastewater treatment by media filtration.

    Science.gov (United States)

    Szögi, A A; Humenik, F J; Rice, J M; Hunt, P G

    1997-09-01

    A media filter was constructed to treat swine wastewater after anaerobic lagoon treatment. The media filter consisted of a tank (1.5-m-diameter x 0.6-m-height) filled with marl gravel. The marl gravel had a carbonate content of 300 g kg-1. Gravel particle size distributions were 85 and 14% in the 4.7- to 12.7-mm and 12.7- to 19-mm size classes, respectively. Pore space of the filtration unit was 57%. Wastewater flow rate was 606 L m-2 d-1, and total Kjeldahl nitrogen (TKN) load was 198 g m-2 d-1. The media filter removed 54% of chemical oxygen demand (COD) content after one cycle, but increased cycling did not produce additional COD reduction. Total suspended solids (TSS) removal after one cycle was 50% of initial levels, and additional cycling reduced TSS levels at a much lower rate of 7% per cycle. Removal efficiencies for total phosphorus (TP) ranged from 37% to 52% (one to four cycles), but long-term phosphorus removal would be limited by the sorption capacity of the gravel. Up to 24% of TKN was converted to nitrate-plus-nitrite-N (NO3+NO2-N). Effluents with high NO3+NO2-N levels can be treated further for denitrification with constructed wetlands or anaerobic lagoon. This is important in cases where land is limited for wastewater application.

  12. Estimated glomerular filtration rate in patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Paula Caitano Fontela

    2014-12-01

    Full Text Available Objective: to estimate the glomerular filtration using the Cockcroft-Gault (CG, Modification of Diet in Renal Disease (MDRD, and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI equations, and serum creatinine in the screening of reduced renal function in patients with type two diabetes (T2DM enrolled in the Family Health Strategy (ESF, Brazilian federal health-care program. Methods: a cross-sectional descriptive and analytical study was conducted. The protocol consisted of sociodemographics, physical examination and biochemical tests. Renal function was analyzed through serum creatinine and glomerular filtration rate (GFR estimated according to the CG, MDRD and CKD-EPI equations, available on the websites of the Brazilian Nephrology Society (SBN and the (NKF. Results: 146 patients aged 60.9±8.9 years were evaluated; 64.4% were women. The prevalence of serum creatinine >1.2 mg/dL was 18.5% and GFR <60 mL/min/1.73m2 totaled 25.3, 36.3 and 34.2% when evaluated by the equations CG, MDRD and CKD-EPI, respectively. Diabetic patients with reduced renal function were older, had long-term T2DM diagnosis, higher systolic blood pressure and higher levels of fasting glucose, compared to diabetics with normal renal function. Creatinine showed strong negative correlation with the glomerular filtration rate estimated using CG, MDRD and CKD-EPI (-0.64, -0.87, -0.89 equations, respectively. Conclusion: the prevalence of individuals with reduced renal function based on serum creatinine was lower, reinforcing the need to follow the recommendations of the SBN and the National Kidney Disease Education Program (NKDEP in estimating the value of the glomerular filtration rate as a complement to the results of serum creatinine to better assess the renal function of patients.

  13. Multiple particle retention mechanisms during filtration in porous media.

    Science.gov (United States)

    Santos, A; Barros, P H L

    2010-04-01

    A statistical model for filtration in porous media is proposed and analytical solutions for particle concentrations are derived. The proposed model takes multiple particle capture mechanisms into account and allows a fundamental physical interpretation of the filtration coefficients. Considering two distinct particle capture mechanisms, the inverse problem solution was discussed and applied to determine the filtration coefficients by fitting experimental data from the literature. Finally, a comparison between the classic and proposed model predictions led to the conclusion that the proposed model showed better agreement with experimental data.

  14. A Combined Approach to Measure Micropollutant Behaviour during Riverbank Filtration

    Science.gov (United States)

    van Driezum, Inge; Saracevic, Ernis; Derx, Julia; Kirschner, Alexander; Sommer, Regina; Farnleitner, Andreas; Blaschke, Alfred Paul

    2016-04-01

    carbamazepine however showed just a slight decrease in concentrations from the river towards the backwater river. Indicator bacteria showed a clear decrease already along the first meters. In the samples taken from the monitoring groundwater wells and abstraction well, faecal indicators were not detected in sample volumes of 1 L each. A combined approach using field measurements and a 3D groundwater transport model proved to be a suitable method to determine the behaviour of various micropollutants and faecal indicators. References Hiscock, K. M. and Grischek, T. (2002) Attenuation of groundwater pollution by bank filtration. Journal of Hydrology, 266(3-4), 139-144. Acknowledgements This paper was supported by FWF (Vienna Doctoral Program on Water Resource Systems W1219-N22) and the GWRS project (Vienna Water) as part of the "(New) Danube-Lower Lobau Network Project" funded by the Government of Austria and Vienna, and the European Agricultural Fund for Rural Development (LE 07-13).

  15. Random times and enlargements of filtrations in a Brownian setting

    CERN Document Server

    Mansuy, Roger

    2006-01-01

    In November 2004, M. Yor and R. Mansuy jointly gave six lectures at Columbia University, New York. These notes follow the contents of that course, covering expansion of filtration formulae; BDG inequalities up to any random time; martingales that vanish on the zero set of Brownian motion; the Azéma-Emery martingales and chaos representation; the filtration of truncated Brownian motion; attempts to characterize the Brownian filtration. The book accordingly sets out to acquaint its readers with the theory and main examples of enlargements of filtrations, of either the initial or the progressive kind. It is accessible to researchers and graduate students working in stochastic calculus and excursion theory, and more broadly to mathematicians acquainted with the basics of Brownian motion.

  16. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    Membrane filtration technologies have emerged as cost competitive and viable techniques in drinking and industrial water production. Despite advancements in membrane manufacturing and technology, membrane scaling and fouling remain major problems and may limit future growth in the industry. Scaling

  17. Performance of multistage filtration using different filter media ...

    African Journals Online (AJOL)

    driniev

    2004-07-03

    Jul 3, 2004 ... This study was aimed at introducing multistage filtration (MSF) (a combination of slow-sand ... nated by human and animal wastes, as well as industrial and ... Geriza Irrigation Scheme (Blue Nile Health Project), Guder's.

  18. Response of arum lily calli to culture filtrate of Pectobacterium ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    . Kumar JV, Kumari BDR, Sujatha G, Castan E (2008). Production of plants resistant to Alternaria carthami via organogenesis and somatic embryogenesis of safflower cv. NARI-6 treated with fungal culture filtrates. Plant Cell ...

  19. Water quality and treatment of river bank filtrate

    NARCIS (Netherlands)

    De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.

    2009-01-01

    In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the

  20. Water quality and treatment of river bank filtrate

    NARCIS (Netherlands)

    De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.

    2010-01-01

    In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the

  1. Filtration recovery of extracellular DNA from environmental ...

    Science.gov (United States)

    qPCR methods are able to analyze DNA from microbes within hours of collecting water samples, providing the promptest notification and public awareness possible when unsafe pathogenic levels are reached. Health risk, however, may be overestimated by the presence of extracellular DNA (eDNA) that is co-recovered by the filtration procedure which is the most commonly used method to concentrate target microbes from environmental waters. Using C. parvum 18S rRNA gene fragment as a representative of eDNA, we examined the impact of filters (types and pore sizes) and physiochemical properties of surface water samples on the recovery of spiked DNA. Our results indicated that binding affinities of various filter membranes were quantifiably different for eDNA fragments with the polycarbonate (PC) binding the least and mixed cellulose acetate and cellulose nitrate (MCE) binding the most as evidenced by up to 16% recovery of the spiked plasmid DNA with a pore size of 0.2µm. Water quality parameters also had a distinct influence on the recovery of eDNA which was enhanced by the presence of high total suspended solid (TSS) concentrations and reduced pH. At pH 5.5, with 150mg/L of clay, DNA recovery was increased to as much as 18%. By shielding the negative charge, thus increasing the interaction of DNA and colloids, the increase of Na+ and Ca+2 concentrations resulted in more DNA binding and consequently more recovery from environmental water samples. Therefore, in addition

  2. Electrically or ultrasonically enhanced membrane filtration of wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Kylloenen, H. [VTT Processes, Jyvaeskylae (Finland)

    2005-10-15

    Flux decline due to concentration polarisation and membrane fouling is a serious problem in membrane filtration. In this thesis the effect of an external DC electric or ultrasonic field separately on the flux in crossflow membrane filtration of wastewater samples was studied. Significant enhancement of the flux compared with the flux with no electric field was achieved in the filtration of model wastewater. The most important parameters for the flux enhancement were the electrophoretic mobility and the applied electric field strength. However, the average electrophoretic mobility of the charged particles in the industrial wastewater samples studied was usually only slightly negative. Thus enhancements when using appropriate electric field strengths were not good enough. Another problem with the industrial wastewater samples was the high conductivity, which caused high consumption of energy. Ultrasound irradiation also provided enhancement in membrane filtration of wastewaters. There are several factors, which affect the cavitation and thus influence the effectiveness of ultrasound in membrane fouling prevention. This thesis was focused on the suitable ultrasound propagation direction and the effect of the transmembrane pressure, which previously have got little attention in the research of ultrasound assisted membrane filtration. According to this study a low frequency ultrasound irradiation from the permeate side of the tight membrane at the transmembrane pressure of zero bar is efficient and, at the same time, a gentle method in membrane cleaning. For open membranes the ultrasound propagation direction should be different or the irradiation from the feed side should be combined with other cleaning techniques. Electrofiltration is not a universal method for the filtration of industrial wastewater. It is a competitive method, when the average electrophoretic mobility in the sample is high and the conductivity is low. Ultrasound assisted filtration is less dependent

  3. Scaling and particulate fouling in membrane filtration systems

    OpenAIRE

    Boerlage, S.F.E.

    2001-01-01

    In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly stringent environmental legislation e.g. Giardia and Cryptosporidum removal guidelines of the Surface Water Treatment Rule (USA). Innovations in membrane manufacturing and process conditions have ...

  4. Local solution method for the problem of enlargement of filtration

    OpenAIRE

    Song, Shiqi

    2013-01-01

    The enlargement of filtration theory is a study of semimartingales when the basic filtration changes. This theory provides particular techniques on stochastic calculus. We present here a technique, that we call the local solution method. We will show, with several examples, that the local solution method is an effective and flexible method. In particular, with the local solution method, we will give a unified proof of three of the classical formulas, namely Jacod's formula, the progressive en...

  5. Glomerular filtration barrier in rat offspring exposed to maternal undernutrition

    Directory of Open Access Journals (Sweden)

    Saleh H. Alwasel

    2017-04-01

    Full Text Available Poor diet during pregnancy can increase blood pressure in offspring of human and laboratory animals. The present study examined the effects of moderate intrauterine undernutrition on the ultrastructure of the glomerular filtration barrier in 20-day-old rat fetuses and six-month-old rat offspring. Pregnant rats were provided with either ad libitum food during pregnancy (control group, C or restricted to 50% of ad libitum food until delivery (food-restricted group, FR. Both groups were given free access to food after birth. The kidneys of embryonic day 20 and six-month-old rats were harvested. Transmission electron micrographs in glomeruli from both groups were obtained to study the ultrastructure of the glomerular filtration barrier. Blood pressure and glomerular filtration rate were measured in six-month-old rats. In comparison to the control group, the FR group had smaller body and kidney weights in both ages. Systemic blood pressure was significantly elevated in the FR group. The glomerular filtration rate was similar in both groups. A study of the glomerular ultrastructure showed a remarkable retardation in the development of the podocyte foot process in the FR group at embryonic day 20. Micrographs also showed remarkable changes in the glomerular filtration barrier of six-month-old rats including an increase in the thickness of the glomerular basement membrane and an increase in the width of filtration slits. These results suggest that maternal food restriction disturbs the development of the glomerular filtration barrier, which may contribute to hypertension in adult rat offspring. The long-term exposure to hypertension and glomerular hyperfiltration may have contributed to the damages observed in the glomerular filtration barrier of six-month-old rats exposed to intrauterine food restriction.

  6. Wind Turbine Gearbox Oil Filtration and Condition Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Shuangwen

    2015-10-25

    This is an invited presentation for a pre-conference workshop, titled advances and opportunities in lubrication: wind turbine, at the 2015 Society of Tribologists and Lubrication Engineers (STLE) Tribology Frontiers Conference held in Denver, CO. It gives a brief overview of wind turbine gearbox oil filtration and condition monitoring by highlighting typical industry practices and challenges. The presentation starts with an introduction by covering recent growth of global wind industry, reliability challenges, benefits of oil filtration and condition monitoring, and financial incentives to conduct wind operation and maintenance research, which includes gearbox oil filtration and condition monitoring work presented herein. Then, the presentation moves on to oil filtration by stressing the benefits of filtration, discussing typical main- and offline-loop practices, highlighting important factors considered when specifying a filtration system, and illustrating real-world application challenges through a cold-start example. In the next section on oil condition monitoring, a discussion on oil sample analysis, oil debris monitoring, oil cleanliness measurements and filter analysis is given based on testing results mostly obtained by and at NREL, and by pointing out a few challenges with oil sample analysis. The presentation concludes with a brief touch on future research and development (R and D) opportunities. It is hoping that the information presented can inform the STLE community to start or redirect their R and D work to help the wind industry advance.

  7. Particle detachment during hydraulic shock loads in granular media filtration.

    Science.gov (United States)

    Kim, J K; Lawler, D F

    2006-01-01

    Particle breakthrough can occur by either the breakoff of previously captured particles (or flocs) or the direct passage of some influent particles through the filter. Filtration experiments were performed in a laboratory-scale filter using spherical glass beads with a diameter of 0.55 mm as collectors. A single type of particle suspension (Min-U-Sil 5) and three different destabilisation methods (pH control, alum and polymer destabilisation) were used to destabilise particles. The filtration velocity of 5 m/h was similar to that used in standard media filtration practice. To assess the possibility of particle detachment during normal filtration, a hydraulic shock load (20% increase of flow rate) was applied after 4 h of normal filtration. The magnitude of particle detachment was proportional to the particle size for non-Brownian particles. At the same time, less favourable particles, i.e. particles with larger surface charge, were easily detached during the hydraulic shock load. Therefore, proper particle destabilisation before filtration is crucial for maximum particle removal, as well as minimum particle breakthrough.

  8. Prediction of glomerular filtration rate in cancer patients by an equation for Japanese estimated glomerular filtration rate.

    Science.gov (United States)

    Funakoshi, Yohei; Fujiwara, Yutaka; Kiyota, Naomi; Mukohara, Toru; Shimada, Takanobu; Toyoda, Masanori; Imamura, Yoshinori; Chayahara, Naoko; Umezu, Michio; Otsuki, Naoki; Nibu, Ken-ichi; Minami, Hironobu

    2013-03-01

    Assessment of renal function is important for safe cancer chemotherapy, and eligibility criteria for clinical trials often include creatinine clearance. However, creatinine clearance overestimates glomerular filtration rate, and various new formulae have been proposed to estimate glomerular filtration rate. Because these were developed mostly in patients with chronic kidney disease, we evaluated their validity in cancer patients without kidney disease. Glomerular filtration rate was measured by inulin clearance in 45 Japanese cancer patients, and compared with creatinine clearance measured by 24-h urine collection as well as that estimated by the Cockcroft-Gault formula, Japanese estimated glomerular filtration rate developed in chronic kidney disease patients, the Modification of Diet in Renal Disease study equation and the Chronic Kidney Disease Epidemiology Collaboration equation. The Modification of Diet in Renal Disease study and Chronic Kidney Disease Epidemiology Collaboration equations were adjusted for the Japanese population by multiplying by 0.808 and 0.813, respectively. The mean inulin clearance was 79.2 ± 18.7 ml/min/1.73 m(2). Bias values to estimate glomerular filtration rate for Japanese estimated glomerular filtration rate, the Cockcroft-Gault formula, creatinine clearance measured by 24-h urine collection, the 0.808 × Modification of Diet in Renal Disease study equation and the 0.813 × Chronic Kidney Disease Epidemiology Collaboration equation were 0.94, 9.75, 29.67, 5.26 and -0.92 ml/min/1.73 m(2), respectively. Precision (root-mean square error) was 14.7, 22.4, 39.8, 16.0 and 14.1 ml/min, respectively. Of the scatter plots of inulin clearance versus each estimation formula, the Japanese estimated glomerular filtration rate correlated most accurately with actual measured inulin clearance. The Japanese estimated glomerular filtration rate and the 0.813 × Chronic Kidney Disease Epidemiology Collaboration equation estimated glomerular

  9. Influence of suspension concentration on cast formation time in pressure filtration

    NARCIS (Netherlands)

    Biesheuvel, Pieter Maarten; Biesheuvel, P.M.; Verweij, H.

    2000-01-01

    Expressions for the formation rate of an incompressible cast in batchwise pressure filtration are formally derived from Darcy's law and Kynch-theory for pure filtration and filtration with sedimentation and compared with experimental results from the filtration of submicron α-alumina dispersed in

  10. Four years experience with filtration systems in commercial nurseries for eliminating Phytophthora species from recirculation water

    Science.gov (United States)

    T. Ufer; M. Posner; H.-P. Wessels; S. Wagner; K. Kaminski; T. Brand; Werres S.

    2008-01-01

    In a four year project, three different filtration systems were tested under commercial nursery conditions to eliminate Phytophthora spp. from irrigation water. Five nurseries were involved in the project. Slow sand filtration systems were tested in three nurseries. In the fourth nursery, a filtration system with lava grains (Shieer® Bio filtration)...

  11. A comparison of facemask and respirator filtration test methods.

    Science.gov (United States)

    Rengasamy, Samy; Shaffer, Ronald; Williams, Brandon; Smit, Sarah

    2017-02-01

    NIOSH published a Federal Register Notice to explore the possibility of incorporating FDA required filtration tests for surgical masks (SMs) in the 42 CFR Part 84 respirator certification process. There have been no published studies comparing the filtration efficiency test methods used for NIOSH certification of N95 filtering facepiece respirators (N95 FFRs) with those used by the FDA for clearance of SMs. To address this issue, filtration efficiencies of "N95 FFRs" including six N95 FFR models and three surgical N95 FFR models, and three SM models were measured using the NIOSH NaCl aerosol test method, and FDA required particulate filtration efficiency (PFE) and bacterial filtration efficiency (BFE) methods, and viral filtration efficiency (VFE) method. Five samples of each model were tested using each method. Both PFE and BFE tests were done using unneutralized particles as per FDA guidance document. PFE was measured using 0.1 µm size polystyrene latex particles and BFE with ∼3.0 µm size particles containing Staphylococcus aureus bacteria. VFE was obtained using ∼3.0 µm size particles containing phiX 174 as the challenge virus and Escherichia coli as the host. Results showed that the efficiencies measured by the NIOSH NaCl method for "N95 FFRs" were from 98.15-99.68% compared to 99.74-99.99% for PFE, 99.62-99.9% for BFE, and 99.8-99.9% for VFE methods. Efficiencies by the NIOSH NaCl method were significantly (p = filtration devices. The higher efficiencies obtained using PFE, BFE and VFE methods show that adding these supplemental particle penetration methods will not improve respirator certification.

  12. Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus

    Directory of Open Access Journals (Sweden)

    S Poonam

    2002-04-01

    Full Text Available Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3 at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type, B. t. var. israelensis (mutant and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm, which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm, the culture filtrates of B. t. var. israelensis (wild type and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.

  13. Water quality and treatment of river bank filtrate

    Directory of Open Access Journals (Sweden)

    W. W. J. M. de Vet

    2010-06-01

    Full Text Available In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the river bank infiltrate but also by water percolating through covering layers. In the polder areas, these top layers consist of peat and deposits from river sediments and sea intrusions.

    This paper discusses the origin and fate of macro components in river bank filtrate, based on extensive full-scale measurements in well fields and treatment systems of the Drinking Water Company Oasen in the Netherlands. First, it clarifies and illustrates redox reactions and the mixing of river bank filtrate and PW as the dominant processes determining the raw water quality for drinking water production. Next, full-scale results are elaborated on to evaluate trickling filtration as an efficient and proven one-step process to remove methane, iron, ammonium and manganese. The interaction of methane and manganese removal with nitrification in these systems is further analyzed. Methane is mostly stripped during trickling filtration and its removal hardly interferes with nitrification. Under specific conditions, microbial manganese removal may play a dominant role.

  14. Technology Review of Modern Gas Turbine Inlet Filtration Systems

    Directory of Open Access Journals (Sweden)

    Melissa Wilcox

    2012-01-01

    Full Text Available An inlet air filtration system is essential for the successful operation of a gas turbine. The filtration system protects the gas turbine from harmful debris in the ambient air, which can lead to issues such as FOD, erosion, fouling, and corrosion. These issues if not addressed will result in a shorter operational life and reduced performance of the gas turbine. Modern day filtration systems are comprised of multiple filtration stages. Each stage is selected based on the local operating environment and the performance goals for the gas turbine. Selection of these systems can be a challenging task. This paper provides a review of the considerations for selecting an inlet filtration system by covering (1 the characteristics of filters and filter systems, (2 a review of the many types of filters, (3 a detailed look at the different environments where the gas turbine can operate, (4 a process for evaluating the site where the gas turbine will be or is installed, and (5 a method to compare various filter system options with life cycle cost analysis.

  15. Deep water treatment of mine water by double stage filtration

    Energy Technology Data Exchange (ETDEWEB)

    Grigoryuk, E.V.; Semenenko, B.A.; Grishchenko, O.V.

    1983-06-01

    Presented was a double stage water filter used for treatment of mine water from underground coal mines in the Donbass. An experimental unit of the filter was developed by DonUGI. It consists of two chambers: the initial filtration chamber filled with claydite (grain size from 1.8 to 2.5 mm) and the chamber for repeated filtration filled with quartz sand (grain size from 0.8 to 1.6 mm). Productivity of the filter ranges from 25 to 30 m/SUP/3/h. The maximum content of solids suspended in mine water filtered by the DonUGI system had to be lower than 200 mg/l. Reagent consumption was about 20 mg/l. One filtration cycle was at least 6 h long. Filter cleaning by a fresh water stream flowing in the opposite direction took 8 min. Content of suspended matter in water after filtration was below 1.5 mg/l. Filter design is shown in a scheme. Advantages of filter use were compared to a system of settling tanks and single stage filtration systems. (In Russian)

  16. Impact of Acidification on Pollutants Fate and Soil Filtration Function

    Directory of Open Access Journals (Sweden)

    Jarmila Makovniková

    2014-12-01

    Full Text Available The objective of this paper was to investigate the effects of simulated acid load on the fate of inorganic pollutants (Cd, Pb, soil sorption potential, soil filtration func-tion. We made use of a short-term acidification pot experiment with grown plant of spring barley cultivated at 4 different soil types (Fluvisol, Cambisol, Stagnosol, Podzol. The potential of soil filtration was evaluated according to the Eq.: [Soil filtration function]=[Potential of soil sorbents]+[Potential of total content of inor-ganic pollutants]. Potential of soil sorbents (PSS is defined by qualitative (pH, or-ganic matter quality - A400/600 and quantitative factors (carbon content-Cox, humus layer thickness-H according to the Eq.:[PSS]=F(pH+F(A465/665+F(Cox*F(H. Acid load significantly influenced soil sorption potential and thus affected increase in Cd and Pb mobility what was reflected in their transfer into the plants. Results of soil filtration function showed significant change of filtration function in Cambisol.

  17. Albuminuria and Glomerular Filtration Rate in Individuals with Type 1 Diabetes Mellitus: Contribution of Metabolic Syndrome.

    Science.gov (United States)

    Uribe-Wiechers, Ana Cecilia; Janka-Zires, Marcela; Almeda-Valdés, Paloma; López-Gutiérrez, Joel; Gómez-Pérez, Francisco J

    2015-01-01

    The development of metabolic syndrome has been described in patients with type 1 diabetes mellitus as the disease progresses over time. The purpose of this study is to assess the relationship between metabolic syndrome, albuminuria, and glomerular filtration rate, as well as to determine the prevalence of metabolic syndrome, in a group of Mexican patients with type 1 diabetes mellitus. We conducted a cross-sectional study that included patients with type 1 diabetes mellitus who were diagnosed over 10 years ago and who are seen at the Diabetes Intensive Control Clinic of the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran in Mexico City. The presence of metabolic syndrome was determined by using the National Cholesterol Education Program-Adult Treatment Panel III (ATP III) criteria. A total of 81 individuals were studied. The prevalence of metabolic syndrome was 18.5% (n = 15). A higher albuminuria was found in subjects with metabolic syndrome (34.9 mg/24 hours; 8.3-169.3) than in those without metabolic syndrome (9.0 mg/24 hours; 5.0-27.0; p = 0.02). Glomerular filtration rate was lower in patients with metabolic syndrome (95.3 ml/minute; [64.9-107.2] vs. 110.2 ml/minute [88.1-120.3]; p = 0.04). After classifying the population according to the number of metabolic syndrome criteria, a progressive increase in albuminuria and a progressive decrease in glomerular filtration rate were found with each additional metabolic syndrome criterion (p = 0.008 and p = 0.032, respectively). After adjusting for age, time from diagnosis, systolic blood pressure, triglycerides, HDL-cholesterol, and treatment with angiotensin receptor blockers or angiotensin converting enzyme inhibitors, we found that age, time from diagnosis, triglycerides, and HDL-cholesterol were independent factors associated with glomerular filtration rate (R2 = 0.286; p < 0.001). Metabolic syndrome was associated with a higher albuminuria and a reduction in glomerular filtration rate in

  18. Filtration des fluides de forage à travers les parois du puits - Bibliographie Filtration of Drilling Fluids Through Borehole Walls

    Directory of Open Access Journals (Sweden)

    Martin M.

    2006-11-01

    Full Text Available Ce document résume un certain nombre de données déjà publiées, relatives à la filtration du fluide de forage, de l'annulaire vers les formations traversées, durant l'approfondissement du puits. On considère : - d'une part, les phénomènes de filtration : . le long des parois (filtration dynamique durant les périodes de circulation - filtration statique durant les arrêts, . sous l'outil ; - d'autre part, certaines de leurs conséquences, en particulier leur influence : . sur la vitesse d'avancement, . sur les risques de coincement de la garniture par pression différentielle, . sur l'envahissement des zones poreuses et perméables. Les phénomènes et leurs conséquences dépendent de très nombreux facteurs dont certains jouent des rôles d'importance très voisine. Leurs études nécessitent des moyens expérimentaux bien adaptés, permettant une simulation suffisamment rigoureuse des conditions de forage. Les résultats ne peuvent être généralisés et doivent être exprimés en fonction des paramètres opératoires choisis. This article reviews varions data which have already been published and which concern the filtration of drilling fluid from the annular space into the formations crossed through during the drilling of a borehole. The following aspects are considered: (i filtration phenomena along borehole walls (dynamic filtration during circulation, and static filtration during shutdowns and underneath the bit; (ii some of the consequences of this filtration, and especially its influence on the rate of penetration, on risks of drill string sticking as the result of differential pressure, and on the invasion of porous and permeable zones. Such phenomena and their consequences depend on a great many factor, some which play roles of quite similar importance. Resaerch on such phenomena requires well suited experimental facilities enabling the sufficiently cllose simulation of drilling conditions. the results of such research

  19. EVALUATION OF EFFECTIVENESS OF HOUSEHOLD DRINKING WATER FILTRATION

    Directory of Open Access Journals (Sweden)

    Karolina Jezierska

    2014-10-01

    Full Text Available The aim of this study was to analyze the effectiveness of household drinking water filtration. This article demonstrates the possibilities of using study on the reaction of ascorbic acid degradation in aqueous solutions to develop a new method for determining the effectiveness of household drinking water filtration. Based on the measurements of absorbance of ascorbic acid a new parameters WCW (Coeffi cient of Water Purity and SF (Filtration Degree were defined. Correlations between the SF and the amount of filtered water (filter usage were investigated. With the filter usage decreasing effectiveness of calcium ions removal and drop of differences in conductivity between the tap and filtered water were observed. SF decreases proportionally to the filter usage and therefore the proposed method can be an effective tool to determine the effectiveness of domestic water filters.

  20. Formation of bacterial streamers during filtration in microfluidic systems.

    Science.gov (United States)

    Marty, Aurélie; Roques, Christine; Causserand, Christel; Bacchin, Patrice

    2012-01-01

    Bacterial behavior during filtration is complex and is influenced by numerous factors. The aim of this paper is to report on experiments designed to make progress in the understanding of bacterial transfer in filters and membranes. Polydimethylsiloxane (PDMS) microsystems were built to allow direct dynamic observation of bacterial transfer across different microchannel geometries mimicking filtration processes. When filtering Escherichia coli suspensions in such devices, the bacteria accumulated in the downstream zone of the filter forming long streamers undulating in the flow. Confocal microscopy and 3D reconstruction of streamers showed how the streamers are connected to the filter and how they form in the stream. Streamer development was found to be influenced by the flow configuration and the presence of connections or tortuosity between channels. Experiments showed that streamer formation was greatest in a filtration system composed of staggered arrays of squares 10 μm apart.

  1. Perlite filtration of phenolic compounds from cigarette smoke.

    Science.gov (United States)

    Rostami-Charati, Faramarz; Robati, Gholamreza Moradi; Naghizadeh, Farhad; Hosseini, Shahnaz; Chaichi, Mohammad Javad

    2013-01-01

    Adsorption of phenolic compounds and chemical analysis of them from a local production cigarette (named by Farvardin cigarette) smoke have been investigated by using perlite filtration. In this research, the mainstream smoke was tested by three filtration methods: Perlite filter, Cambridge filter and general cigarette filter. Then the used filter was extracted by pure methanol as solvent. After that, the extracted solution was analysed by GC-MS. By this consideration, the phenolic derivatives such as phenol, hydroquinone, resorcinol, pyrocatechol, m-cresol, p-cresol and o-cresol were detected. The structure of the perlite filtration after absorption was studied by SEM. In addition, its chemical structure was investigated by XRD and XRF.

  2. Simulations of Microbial-Enhanced Oil Recovery: Adsorption and Filtration

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie; Nesterov, Igor; Shapiro, Alexander

    2014-01-01

    is introduced to study the process efficiency: the dimensionless time at which average recovery between pure water injection and maximum surfactant effect is reached. This characteristic recovery period (CRP) was studied as a function of the different MEOR parameters such as bacterial activity, filtration......In the context of microbial-enhanced oil recovery (MEOR) with injection of surfactant-producing bacteria into the reservoir, different types of bacteria attachment and growth scenarios are studied using a 1D simulator. The irreversible bacteria attachment due to filtration similar to the deep bed...... filtration (DBF) is examined along with the commonly used reversible equilibrium adsorption (REA). The characteristics of the two models are highlighted. The options for bacteria growth are the uniform growth in both phases and growth of attached bacteria only. It is found that uniform growth scenario...

  3. Fusion Kalman filtration with k-step delay sharing pattern

    Directory of Open Access Journals (Sweden)

    Duda Zdzisław

    2015-09-01

    Full Text Available A fusion hierarchical state filtration with k−step delay sharing pattern for a multisensor system is considered. A global state estimate depends on local state estimates determined by local nodes using local information. Local available information consists of local measurements and k−step delay global information - global estimate sent from a central node. Local estimates are transmitted to the central node to be fused. The synthesis of local and global filters is presented. It is shown that a fusion filtration with k−step delay sharing pattern is equivalent to the optimal centralized classical Kalman filtration when local measurements are transmitted to the center node and used to determine a global state estimate. It is proved that the k−step delay sharing pattern can reduce covariances of local state errors.

  4. A three plus three parameters mechanistic model for viral filtration.

    Science.gov (United States)

    Misra, Prakhar; Sinha, Abhishek; Rathore, Anurag S; Shukla, Anupam; Mir, Fasil Q

    2017-07-11

    Viral filtration is an expensive regulatory requirement in downstream processing of monoclonal antibodies (mAbs). This process step is typically operated with an overdesigned filter in order to account for any batch to batch variability in the filter, as well as the feed characteristics. Here, we propose a simple, six-parameter mechanistic model for viral filtration where three parameters are membrane-specific while the other three depend on feed characteristics and membrane-feed interactions. Viruses are considered as passive particles which are retained by the membrane on the basis of size exclusion. The model envisages that the viral filter contains two kind of pores: virus-retentive, small-sized pores and non-retentive, large-sized pores. The small-sized pores get blocked during filtration resulting in decrease in active membrane area, while the large-sized pores get constricted during filtration. The length of constricted part increases during filtration and contributes to increase in hydraulic resistance of the filter. Rate of these processes (blocking and constriction) are assumed to be proportional to the instantaneous rate of retention of the viral particles. The general nature of the model is validated with the experimental data on viral filtration for four different commercial membranes used in biotech industries as well as different model viruses. The proposed model has been demonstrated to describe the behavior of filters with very good accuracy. The best-fit model parameter values indicate about the various phenomena that are responsible for differences in the behavior of the membranes as well as change in retention and flux with feed concentration. The proposed model can be used for improving design of virus filters as well as in appropriate sizing of the filters during processing. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 2017. © 2017 American Institute of Chemical Engineers.

  5. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  6. Fine dust filtration using a metal fiber bed.

    Science.gov (United States)

    Lee, Kyung Mi; Lee, Young Sup; Jo, Young Min

    2006-08-01

    A bed-type filter composed of thin metal alloy fiber was closely examined with dust capturing in cold and hot runs. The investigation of an individual mechanism across the filter bed indicated that the aerated dust could be initially collected by depth filtration, and after a while, surface filtration dominated the overall dust collection. The present metal fiber bed was comparable to the conventional ceramic filters because of its good collection efficiency with low pressure drop. It also showed potential to be used as a prefilter in a diesel exhaust trapping system.

  7. Pathogen filtration to control plant disease outbreak in greenhouse production

    Science.gov (United States)

    Jeon, Sangho; Krasnow, Charles; Bhalsod, Gemini; Granke, Leah; Harlan, Blair; Hausbeck, Mary; Zhang, Wei

    2016-04-01

    Previous research has been extensively focused on understanding the fate and transport of human microbial pathogens in soil and water environments. However, little is known about the transport of plant pathogens, although these pathogens are often found in irrigation waters and could cause severe crop damage and economical loss. Water mold pathogens including Phytophthora spp. and Pythium spp. are infective to a wide range of vegetable and floriculture crops, and they are primarily harbored in soils and disseminated through water flow. It is challenging to control these pathogens because they often quickly develop resistance to many fungicides. Therefore, this multi-scale study aimed to investigate physical removal of plant pathogens from water by filtration, thus reducing the pathogen exposure risks to crops. In column-scale experiments, we studied controlling factors on the transport and retention of Phytophthora capsici zoospores in saturated columns packed with iron oxide coated-sand and uncoated-sand under varying solution chemistry. Biflagellate zoospores were less retained than encysted zoospores, and lower solution pH and greater iron oxide content increased the retention of encysted zoospores. These results provided insights on environmental dispersal of Phytophthora zoospores in natural soils as well as on developing cost-effective engineered filtration systems for pathogen removal. Using small-scale greenhouse filtration systems, we further investigated the performance of varying filter media (i.e., granular sand, iron oxide coated ceramic porous media, and activated carbon) in mitigating disease outbreaks of Phytophthora and Pythium for greenhouse-grown squash and poinsettia, respectively, in comparison with fungicide treatment. For squash, filtration by iron oxide coated media was more effective in reducing the Phytophthora infection, comparing to sand filtration and fungicide application. For poinsettia, sand filtration performed better in controlling

  8. Spin filtration of unpolarized electrons by impurity centers in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bobin, E. G.; Berdinskiy, V. L., E-mail: bvl@unpk.osu.ru [Orenburg State University (Russian Federation)

    2011-11-15

    It is shown that unpolarized paramagnetic centers can implement the spin filtration of unpolarized conduction electrons in semiconductors. This ability of paramagnetic centers is caused by the difference in the spin evolution of the states of electron-paramagnetic-center pairs and by the spin selectivity of electron capture exclusively from singlet pairs. The electron spin polarization should be opposite to the paramagneticcenter polarization. To implement spin filtration, an external magnetic field is necessary. The polarization can attain the largest values ({approx}10%) if the probability of spin-selective electron capture from singlet pairs exceeds the pair-decay rate by a factor of 5-7.

  9. Filtration ATF in automatic transmissions (AT of cars

    Directory of Open Access Journals (Sweden)

    Tadeusz Dziubak

    2014-03-01

    Full Text Available Functions and conditions of work of suction ATF filters are presented. Requirements ofATF filters are discussed. Sources of contaminations ATF are presented. ATF filtration system wascharacterized. Classification of ATF filters and their selection of design solutions are presented. Filtermaterials used for the production of ATF suction filters are presented and characterized. Conditions ofthe work of suction ATF filters were analyzed. Hydraulic and filtration characteristics are discussed.[b]Keywords: AT[/b] — automatic transmissions, ATF — automatic transmission fluid, ATF filter

  10. Visualisation studies and glomerular filtration in early diabetic rats.

    Science.gov (United States)

    Nakamoto, Hiroshi

    2017-01-04

    The purpose of this mini-review is to show that more modern multi-photon microscopy approaches allow quantitative glomerular filtration experiments. Modern science has now entered a transition period from light microscopy to multi-photon confocal microscopy. Since the late 20th century, multi-photon microscopy has been applied in the study of organ function. In keeping with observations made in renal physiology and other representative studies throughout this transition period, and in the context of advancing microscopy techniques, this review has been presented as a comment on the glomerular filtration barrier, with a focus on the early aetiopathogenesis of diabetes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    Directory of Open Access Journals (Sweden)

    L. D. Sánchez

    2012-12-01

    Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

  12. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

    Science.gov (United States)

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

  13. Modeling and analytical simulation of high-temperature gas filtration ...

    African Journals Online (AJOL)

    High temperature filtration in combustion and gasification processes is a highly interdisciplinary field. Thus, particle technology in general has to be supported by elements of physics, chemistry, thermodynamics and heat and mass transfer processes. Presented in this paper is the analytical method for describing ...

  14. Glomerular filtration rate profiles in paediatric patients on cancer ...

    African Journals Online (AJOL)

    Background: An accurate estimation of renal function in children is important in optimising the dose of many drugs used in paediatric oncology for allowing clinical monitoring of the nephrotoxic effects of cytotoxic agents such as cisplatin. The glomerular filtration rate (GFR) is widely accepted as the best index of renal ...

  15. Estimated Glomerular Filtration Rate and Risk of Survival in Acute ...

    African Journals Online (AJOL)

    Objective: To assess the risk of survival in acute stroke using the MDRD equation derived estimated glomerular filtration rate. Design: A prospective observational cross-sectional study. Setting: Medical wards of a tertiary care hospital. Subjects: Eighty three acute stroke patients had GFR calculated within 48 hours of ...

  16. Cumulative analysis of measurement processes and a correcting filtration

    OpenAIRE

    MEHDIYEVA A.M.

    2016-01-01

    The offered systematic approach to creation of information-measuring systems of considered parameters consists of cumulative analysis of measurement processes and a correcting filtration for the purpose of achievement of the balanced metrological, structurally-algorithmic and functional efficiency indicators of developed means.

  17. Hybrid filtration method for pre-treatment of stormwater.

    Science.gov (United States)

    Johir, M A H; Vigneswaran, S; Kandasamy, J

    2010-01-01

    In this study the hybrid filtration process (combining fibre filter with deep bed dual media filtration) was investigated as pre-treatment to stormwater. This process was investigated in-terms of reduction in turbidity, dissolved organic carbon (DOC), colour, headloss development across the filters, suspended solids removal, organic matter removal, nutrients and heavy matter (such as iron, copper, lead, zinc) removal efficiency. A comparison was made between the hybrid filter with single media (sand) deep bed filter and fibre filter. It was found that the hybrid filtration system successfully removed turbidity (98%), colour (99%), suspended solids (99%), and DOC (55%). The removal efficiency of heavy metal was relatively low as the concentration of heavy metals present in stormwater was low. The removal efficiency of nitrate, nitrite and phosphorous (as orthophosphate) was 27, 35 and 72% respectively. Hybrid filtration processes showed a better reduction of Modified Fouling Index (MFI) value (from 15.500 s/l(2) to 9 s/l(2)) compared with single media sand, anthracite and fibre filter which were 35 s/l(2), 13 s/l(2)and 14 s/l(2) respectively when operated at FeCl(3) dose of 15 mg/l.

  18. Successful Treatment Of Homozygous Familial Hypercholesterolemia Using Cascade Filtration Plasmapheresis

    Directory of Open Access Journals (Sweden)

    Fatih Kardas

    2012-12-01

    Full Text Available OBJECTIVE: The aim of our study is to discuss the efficacy of low-density lipoprotein-cholesterol (LDL-C apheresis procedure using the cascade filtration system for pediatric patients with homozygous familial hypercholesterolemia (FH, and to clarify the adverse effects and difficulties. METHODS: LDL apheresis using the cascade filtration system was performed in 3 pediatric patients with homozygous FH. In total, 120 apheresis sessions were performed for all patients. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dl to 145 ± 43 mg/dl (p<0.05. We determined an acute mean reduction in the plasma levels of total cholesterol (57.9%, LDL cholesterol (70.8%, and high-density lipoprotein (HDL cholesterol (40.7%. Treatments were well tolerated. The most frequent clinical adverse effects were hypotension in 3 sessions (2.5%, chills/feeling cold (1.7% in 2 sessions, and nausea and vomiting in 3 sessions (2.5%. CONCLUSION: Our experience with three patients using the cascade filtration system were, good clinical outcomes, laboratory findings, safety of usage, minor adverse effects and technical problems.

  19. Reduced glomerular filtration rate as a predictor of coronary artery ...

    African Journals Online (AJOL)

    Background: Chronic kidney disease is independently associated with cardiovascular disease (CVD) events in high-risk populations according to several studies. However, findings from community-based population studies are insufficient. We studied the relationship between estimated glomerular filtration rate (eGFR) and ...

  20. Glomerular filtration rate in steady state children with sickle cell ...

    African Journals Online (AJOL)

    Background: Sickle cell anaemia (SCA) affects mostly people of African origin. It causes kidney problems termed Sickle cell nephropathy (SCN). Increased glomerular filtration rate (GFR) has been documented as one of the functional abnormalities seen in young SCA patients. Objective: To estimate GFR in Nigerian ...

  1. Estimated glomerular filtration rate in the nephrotic syndrome

    NARCIS (Netherlands)

    Hofstra, J.M.; Willems, J.L.; Wetzels, J.F.M.

    2011-01-01

    BACKGROUND: Plasma creatinine concentration and creatinine-based equations are most commonly used as markers of glomerular filtration rate (GFR). The abbreviated MDRD formula is considered the best available formula. Altered renal handling of creatinine, which may occur in the nephrotic syndrome,

  2. Superamphiphobic nanofibrous membranes for effective filtration of fine particles.

    Science.gov (United States)

    Wang, Na; Zhu, Zhigao; Sheng, Junlu; Al-Deyab, Salem S; Yu, Jianyong; Ding, Bin

    2014-08-15

    The worldwide demands are rising for an energy-efficient and cost-effective approach that can provide advanced nanofibrous membranes with high filtration performance and superior antifouling properties. Here we report a novel synthesized fluorinated polyurethane (FPU) modified nanofibrous membrane optimized to achieve oil and non-oil aerosol particle filtration. By employing the FPU incorporation, the polyacrylonitrile/polyurethane (PAN/PU) composite membranes were endowed with superhydrophobicity with a water contact angle of 154° and superoleophobicity with an oil contact angle of 151°. Morphology, surface wettability, porous structure, and filtration performance could be manipulated by tuning the solution composition as well as the hierarchical structure. Furthermore, the as-prepared membranes can capture, for the first time, a range of different oil aerosol particles in a single-unit operation, with >99.9% filtration efficiency, by using the combined contribution of fiber diameter and surface roughness acting on the objective particles. Exemplified here by the construction of superamphiphobic nanofibrous membrane, numerous applications of this medium includes high efficiency particulate air filters, ultra-low penetration air filters, and respiratory protection equipment. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Particle segregation during pressure filtration for cast formation

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Biesheuvel, Pieter Maarten

    2000-01-01

    When pressure filtration is used to produce composite materials from a mixed suspension, segregation of the different particle types is apt to occur due to different sedimentation velocities. This results in an inhomogeneous, thus inferior product. To understand and reduce segregation, a model is

  4. The filtration properties of porous diatomite | Odusote | Nigerian ...

    African Journals Online (AJOL)

    ... through this material is fractal in the regime of low intensity transport. No fractal behaviour was observed under high intensity, indicating that the geometry of the material is subdued under high external driving forces. Keywords: Filtration, porous media, diatomite, intensity transport, fractal. > Nigerian Journal of Physics Vol.

  5. Membrane device and process for mass exchange, separation, and filtration

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L.

    2016-11-15

    A membrane device and processes for fabrication and for using are disclosed. The membrane device may include a number of porous metal membranes that provide a high membrane surface area per unit volume. The membrane device provides various operation modes that enhance throughput and selectivity for mass exchange, mass transfer, separation, and/or filtration applications between feed flow streams and permeate flow streams.

  6. Initial testing of electrospun nanofibre filters in water filtration ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate the use of nanofibre microfiltration membranes, spun by an innovative electrospinning technique, in water filtration applications. As such, this study bridges the gap between developments in electrospinning techniques for the production of flat-sheet membranes and the application of ...

  7. Sand-Filtration System For Improving Water Quality For Rural ...

    African Journals Online (AJOL)

    The performance of a pilot sand filtration plant for a small town water supply was monitored over a seven month period to evaluate the physico-chemical and bacteriological quality of the filtered water from a system installed at Assin Praso in the Central Region of Ghana. The sand filter was effective in reducing turbidity by ...

  8. A biocoagulant slow sand filtration for disinfection of Toxoplasma ...

    African Journals Online (AJOL)

    Considering that is widely used for various domestic chores; filtration disinfection of T. gondii was considered. A bench scale disinfection of oocysts of T. gondii with 0.2 g of powdered Moringa oleifera seeds per 10 ml of contaminated water from Mezam River showed a reduction of 50 oocysts per 10 ml to 10 oocysts in 15 ...

  9. RIVERBANK FILTRATION AS A PRETREATMENT FOR NANOFILTRATION MEMBRANES

    Science.gov (United States)

    The loss of membrane efficiency due to fouling is one of the main impediments to the development of membrane processes for use in drinking water treatment. Surface waters, in general, have a greater proclivity towards fouling as compared to groundwaters. Riverbank filtration ch...

  10. Optimal adaptive scheduling and control of beer membrane filtration

    NARCIS (Netherlands)

    Willigenburg, van L.G.; Vollebregt, H.M.; Sman, van der R.G.M.

    2015-01-01

    An adaptive optimal scheduling and controller design is presented that attempts to improve the performance of beer membrane filtration over the ones currently obtained by operators. The research was performed as part of a large European research project called EU Cafe with the aim to investigate the

  11. Modelling Real World Using Stochastic Processes and Filtration

    Directory of Open Access Journals (Sweden)

    Jaeger Peter

    2016-03-01

    Full Text Available First we give an implementation in Mizar [2] basic important definitions of stochastic finance, i.e. filtration ([9], pp. 183 and 185, adapted stochastic process ([9], p. 185 and predictable stochastic process ([6], p. 224. Second we give some concrete formalization and verification to real world examples.

  12. Effect of filtration on subsequently stored platelet concentrates

    NARCIS (Netherlands)

    Joustra-Dijkhuis, A. M.; Boomgaard, M. N.; Pietersz, R. N.; Steneker, I.; de Korte, D.; Loos, J. A.; Reesink, H. W.

    1994-01-01

    The effect of filtration on the quality of platelet concentrates (PC) during storage was investigated. Two leukocyte depletion filters (Pall PL50HF and Sepacell PL-10A) were applied to filter PC made from a pool of 4 buffy coats. For each experiment 3 PC were pooled and divided into 3 identical PC

  13. Effect of internal filtration on slurry reactor performance

    NARCIS (Netherlands)

    Huizenga, P.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    1999-01-01

    In slurry bubble column reactors, generally small particles (<200 m) are applied. These particles often introduce a strenuous liquid-solid separation in processes involving liquid-phase products. This operation can be facilitated by performing filtration inside the reactor and thereby utilizing the

  14. Initial testing of electrospun nanofibre filters in water filtration ...

    African Journals Online (AJOL)

    2009-11-17

    Nov 17, 2009 ... 1 Research Group EnBichem, Departement of Industrial Engineering and Technology, University College West Flanders,. Ghent University Association ... techniques for the production of flat-sheet membranes and the application of these membranes in water filtration. Three dif- ferent applications were ...

  15. Simulation of impaction filtration of aerosol droplets in porous media

    NARCIS (Netherlands)

    Ghazaryan, L.; Lopez Penha, D.J.; Geurts, Bernardus J.; Stolz, S.; Stolz, Steffen; Winkelmann, Christoph; Pereira, J.C.F; Sequeira, A.; Pereira, J.M.C.

    2010-01-01

    We report on the development of a method to simulate from first principles the particle filtration efficiency of filters that are composed of structured porous media. We assume that the ratio of particle density to the fluid density is high. We concentrate on the motion of the particles in a laminar

  16. Experiences on dual media filtration of WWTP effluent.

    Science.gov (United States)

    Scherrenberg, S M; Postma, P; Neef, R; Menkveld, H W H; Bechger, M; van der Graaf, J H J M

    2011-01-01

    This research is legislation driven by the European Water Framework Directive (WFD) and the Dutch Fourth Memorandum on Water Management. The objective of this research is to achieve the removal of total nitrogen and total phosphorus by Dual Media Filtration. The target value during this research for total nitrogen is 2.2 mg/L and for total phosphorus 0.15 mg/L. The results show that for NOx-N concentrations in the WWTP effluent up to 10 mg/L, a stable operation of the process can be reached with removal rates of 80% to 90%. The maximum nitrogen removal rate was 3.5 kg N/(m3.d). Above 10 mg/L a risk of filter bed clogging occurred. When the orthophosphorus concentration in the WWTP effluent exceeds the maximum of 0.3 mg/L, the total phosphorus concentration in the filtrate water will exceed the target value of 0.15 mg P-total/L. Temperature has a large impact in the phosphorus removal; the optimum temperature range is within 13 degrees C-18 degrees C. In conclusion, Dual Media Filtration is capable of producing reusable water with total phosphorus concentrations of filtrate water of <2.2 mg/L a NOx-N removal efficiency of nearly 100% is required.

  17. Assessment of endophytic fungi cultural filtrate on soybean seed ...

    African Journals Online (AJOL)

    Soybean seeds have high amount of isoflavones but its germination is often confronted with a variety of environmental problems resulting in low germination rate and growth. To overcome this in eco-friendly manner, we investigated the influence of cultural filtrate (CF) of gibberellins-producing endophytic fungi on soybean ...

  18. Effect of hypothermic pulmonary artery flushing on capillary filtration coefficient.

    Science.gov (United States)

    Andrade, R S; Wangensteen, O D; Jo, J K; Tsai, M Y; Bolman, R M

    2000-07-27

    We previously demonstrated that surfactant dilution and inhibition occur immediately after pulmonary artery flushing with hypothermic modified Euro-Collins solution. Consequently, we speculated that increased capillary permeability contributed to these surfactant changes. To test this hypothesis, we evaluated the effects of hypothermic pulmonary artery flushing on the pulmonary capillary filtration coefficient (Kfc), and additionally performed a biochemical analysis of surfactant. We used a murine isolated, perfused lung model to measure the pulmonary capillary filtration coefficient and hemodynamic parameters, to determine the wet to dry weight ratio, and to evaluate surfactant by biochemical analysis of lung lavage fluid. We defined three study groups. In group I (controls), we harvested lungs without hypothermic pulmonary artery flushing, and measured Kfc immediately. In group II (in situ flush), we harvested lungs after hypothermic pulmonary artery flushing with modified Euro-Collins solution, and then measured Kfc. Experiments in groups I and II were designed to evaluate persistent changes in Kfc after pulmonary artery flushing. In group III (ex vivo flush), we flushed lungs ex vivo to evaluate transient changes in Kfc during hypothermic pulmonary artery flushing. Groups I and II did not differ significantly in capillary filtration coefficient and hemodynamics. Group II showed significant alterations on biochemical surfactant analysis and a significant increase in wet-to-dry weight ratio, when compared with group I. In group III, we observed a significant transient increase in capillary filtration coefficient during pulmonary artery flushing. Hypothermic pulmonary artery flushing transiently increases the capillary filtration coefficient, leads to an increase in the wet to dry weight ratio, and induces biochemical surfactant changes. These findings could be explained by the effects of hypothermic modified Euro-Collins solution on pulmonary capillary

  19. Impacts of extreme flooding on riverbank filtration water quality.

    Science.gov (United States)

    Ascott, M J; Lapworth, D J; Gooddy, D C; Sage, R C; Karapanos, I

    2016-06-01

    Riverbank filtration schemes form a significant component of public water treatment processes on a global level. Understanding the resilience and water quality recovery of these systems following severe flooding is critical for effective water resources management under potential future climate change. This paper assesses the impact of floodplain inundation on the water quality of a shallow aquifer riverbank filtration system and how water quality recovers following an extreme (1 in 17 year, duration >70 days, 7 day inundation) flood event. During the inundation event, riverbank filtrate water quality is dominated by rapid direct recharge and floodwater infiltration (high fraction of surface water, dissolved organic carbon (DOC) >140% baseline values, >1 log increase in micro-organic contaminants, microbial detects and turbidity, low specific electrical conductivity (SEC) 400% baseline). A rapid recovery is observed in water quality with most floodwater impacts only observed for 2-3 weeks after the flooding event and a return to normal groundwater conditions within 6 weeks (lower fraction of surface water, higher SEC, lower DOC, organic and microbial detects, DO). Recovery rates are constrained by the hydrogeological site setting, the abstraction regime and the water quality trends at site boundary conditions. In this case, increased abstraction rates and a high transmissivity aquifer facilitate rapid water quality recoveries, with longer term trends controlled by background river and groundwater qualities. Temporary reductions in abstraction rates appear to slow water quality recoveries. Flexible operating regimes such as the one implemented at this study site are likely to be required if shallow aquifer riverbank filtration systems are to be resilient to future inundation events. Development of a conceptual understanding of hydrochemical boundaries and site hydrogeology through monitoring is required to assess the suitability of a prospective riverbank filtration

  20. Filtration effectiveness of HVAC systems at near-roadway schools.

    Science.gov (United States)

    McCarthy, M C; Ludwig, J F; Brown, S G; Vaughn, D L; Roberts, P T

    2013-06-01

    Concern for the exposure of children attending schools located near busy roadways to toxic, traffic-related air pollutants has raised questions regarding the environmental benefits of advanced heating, ventilation, and air-conditioning (HVAC) filtration systems for near-road pollution. Levels of black carbon and gaseous pollutants were measured at three indoor classroom sites and at seven outdoor monitoring sites at Las Vegas schools. Initial HVAC filtration systems effected a 31-66% reduction in black carbon particle concentrations inside three schools compared with ambient air concentrations. After improved filtration systems were installed, black carbon particle concentrations were reduced by 74-97% inside three classrooms relative to ambient air concentrations. Average black carbon particle concentrations inside the schools with improved filtration systems were lower than typical ambient Las Vegas concentrations by 49-96%. Gaseous pollutants were higher indoors than outdoors. The higher indoor concentrations most likely originated at least partially from indoor sources, which were not targeted as part of this intervention. Recent literature has demonstrated adverse health effects in subjects exposed to ambient air near major roadways. Current smart growth planning and infill development often require that buildings such as schools are built near major roadways. Improving the filtration systems of a school's HVAC system was shown to decrease children's exposure to near-roadway diesel particulate matter. However, reducing exposure to the gas-phase air toxics, which primarily originated from indoor sources, may require multiple filter passes on recirculated air. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  1. The scientific evidence of arterial line filtration in cardiopulmonary bypass.

    Science.gov (United States)

    Johagen, Daniel; Svenmarker, Staffan

    2016-09-01

    The indication for arterial line filtration (ALF) is to inhibit embolisation during cardiopulmonary bypass. Filtration methods have developed from depth filters to screen filters and from a stand-alone component to an integral part of the oxygenator. For many years, ALF has been a standard adopted by a majority of cardiac centres worldwide. The following review aims to summarize the available evidence in support for ALF and report on its current practice in Europe. The principles and application of ALF in Europe was investigated using a survey conducted in 2014. The scientific evidence for ALF was examined by performing a systematic literature search in six different databases, using the following search terms: "Cardiopulmonary bypass AND filters AND arterial". The primary endpoint was protection against cerebral injury verified by the degree of cerebral embolisation or cognitive tests. The secondary endpoint was improvement of the clinical outcome verified elsewise. Only randomised clinical trials were considered. The response rate was 31% (n=112). The great majority (88.5%) of respondents were using ALF, following more than 10 years of experience. Integrated arterial filtration was used by 55%. Of respondents not using ALF, fifty-four percent considered starting using integrated arterial filtration. The systematic literature database search returned 180 unique publications where 82 were specifically addressing ALF in cardiopulmonary bypass. Only four out of the 82 identified publications fulfilled our inclusion criteria. Of these, three were more than 20 years old and based on the use of bubble oxygenation. ALF is a standard implemented in a majority of cardiopulmonary bypass procedures in Europe. The level of scientific evidence available in support of current arterial line filtration methods in cardiopulmonary bypass is, however, poor. Large, well-designed, randomised trials are warranted. © The Author(s) 2015.

  2. The glomerular filtration rate during pregnancy : Saline infusion enhances the glomerular filtration rate in the pregnant rat

    NARCIS (Netherlands)

    Faas, MM; Schuiling, GA; Klok, PA; Valkhof, N; Bakker, WW

    1996-01-01

    The glomerular filtration rate (GFR) of pregnant rats is generally believed to exceed non-pregnant values. This notion is primarily based upon standard inulin clearances. However, the inulin clearance requires continuous infusion of inulin usually dissolved in saline. Since saline infusion per se in

  3. Fluorometric Method for Determining the Efficiency of Spun-Glass Air Filtration Media

    Science.gov (United States)

    Sullivan, James F.; Songer, Joseph R.; Mathis, Raymond G.

    1967-01-01

    The procedures and equipment needed to measure filtration efficiency by means of fluorescent aerosols are described. The filtration efficiency of individual lots of spun-glass air filtration medium or of entire air filtration systems employing such media was determined. Data relating to the comparative evaluation of spun-glass filter media by means of the fluorometric method described, as well as by conventional biological procedures, are presented. PMID:6031433

  4. Static and dynamic filtrations of different clay, electrolytes, polymer systems; Filtrations statiques et dynamiques de differents systemes argile, electrolytes, polymere

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.

    1996-04-16

    Filtration properties of model drilling fluids composed of water, clays, electrolytes and water soluble polymers have been studied in static and dynamic conditions on paper filters and rock slices. Filtration experiments combined with cake observations by cryo-S.E.M. and T.E.M., show the influence of the size shape of clay particles as well as their associating mode in suspension, on the texture of the cake, its permeability, and relaxation properties. These parameters depend on the nature of the electrolyte. The polymer reduces the cake permeability by enhancing the dispersion of the clay within the suspension, but mainly by plugging the porous network due its auto aggregation properties. The cake construction in dynamic conditions, is related to the state of aggregation of the initial suspension, its poly-dispersity, its sensitivity to shear rates, and also, to the permeability of the cake built at the beginning of the filtration. In all cases, the rate of thickening of the cake is slower and larger filtrate volumes are obtained compared to the static conditions. Shear rate has two effects: first, to dissociate the weak aggregates in suspension, second, to impose a size selection of the particles in the case of a poly-dispersed suspension. At high shear rates, a cake of constant thin thickness is quickly obtained. The thickness of this limiting cake depends on the fraction of small particles present in suspension, or that can be formed by dissociation of weak aggregates under shear rate. The permeability of this limiting cake formed in dynamic conditions is, as in static conditions, controlled by the size and the shape of the particles that form the cake or by the presence of a build loss reducer water soluble polymer. Filtrations carried out on Fontainebleau sandstones allow to visualize the internal cake and to precise the risks of formation damage by the drilling fluid. (author) 127 refs.

  5. Description of three-phase filtration with a novel dimensionless number.

    NARCIS (Netherlands)

    Huizenga, P.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    1998-01-01

    Internal filtration in slurry bubble columns offers a possible solution to the filtration problems related to this reactor type. The applicability of the concept has already been demonstrated at full-scale for wastewater treatment, even though a theoretical description of internal filtration is

  6. Leucocyte depletion during cardiac surgery : a comparison of different filtration strategies

    NARCIS (Netherlands)

    de Vries, AJ; Gu, YJ; Post, WJ; Vos, P; Stokroos, Ietse; Lip, Harm; van Oeveren, W

    The results of leucocyte filtration during cardiac surgery are conflicting. This may be due to timing and duration of the filtration procedure, and to flow and pressure conditions in the filter. Therefore, we prospectively compared three major leucocyte filtration strategies in cardiac surgical

  7. Facilitating community water supply treatment : from transferring filtration technology to multi-stakeholder learning

    NARCIS (Netherlands)

    Visscher, J.T.

    2006-01-01

    For more than a quarter of a century, IRC has been supporting the development of Slow Sand Filtration (SSF) and more recently, together with CINARA, the pioneering of Multi-Stage Filtration (MSF) - a combination of Gravel Filtration and SSF that has been shown to have great potential as an effective

  8. 40 CFR 141.717 - Pre-filtration treatment toolbox components.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Pre-filtration treatment toolbox... Cryptosporidium Requirements for Microbial Toolbox Components § 141.717 Pre-filtration treatment toolbox... softening stages prior to filtration. Both softening stages must treat the entire plant flow taken from a...

  9. Analysis of filtration properties of locally sourced base oil for the ...

    African Journals Online (AJOL)

    ... of locally sourced oil like, groundnut oil, melon oil, vegetable oil, soya oil and palm oil as substitute for diesel oil in formulating oil base drilling fluids relative to filtration properties. The filtrate volumes of each of the oils were obtained for filtration control analysis. With increasing potash and industrial starch quantities during ...

  10. 76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

    Science.gov (United States)

    2011-12-30

    ... COMMISSION Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units AGENCY: Nuclear...-1274, ``Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of....'' This guide applies to the design, inspection, and testing of air filtration and iodine adsorption units...

  11. Public health protection through bank filtration - Kearney Nebraska case study

    Science.gov (United States)

    Esseks, E.; Bellamy, W.; Heinemann, T.; Stocker, K.

    2003-04-01

    The investigation of Kearney's bank filtration system provides further evidence of this technology's capability to assist in providing public health protection, as it relates to drinking water. The results of hydrogeologic and treatment studies demonstrate the capabilities of the Platte River aquifer materials, in this locale, to remove pathogens and their surrogates. Continual monitoring and evaluations will establish the system’s longevity and continued treatment efficacy. The City of Kearney is located in south central Nebraska. The City owns and operates a public water system that serves approximately 24,889 people. The water system includes 12 wells located on Killgore Island in the Platte River. In 1994, the Nebraska Department of Health and Human Services System (Department) determined that 3 wells in the wellfield serving the City of Kearney were ground water under the direct influence of surface water. This determination was based on results of microscopic particulate analysis (MPA). The City of Kearney undertook the natural bank filtration study to determine whether natural bank filtration was occurring at the site and if the filtration was sufficient to meet pathogen treatment requirements designed to protect public health. A preliminary study was undertaken from June through October 1995. This coincided with the City’s peak pumping time, which may be the time when the influence of the River is greatest on the wellfield wells. Hydrogeologic studies assisted in selecting wells that were at highest risk based on shortest travel times and greatest differential head. Data collected included particle counts, MPAs, turbidity, coliform, centrifugate pellet evaluation (CPE) volumes, pH, conductivity, and temperature. Following analysis of data collected during the preliminary 18-week study the Department granted conditional approval of 2-log credit for removal of Giardia lamblia and 1-log credit for removal of viruses through bank filtration, pending the

  12. GPU-Based Cloud Service for Smith-Waterman Algorithm Using Frequency Distance Filtration Scheme

    Directory of Open Access Journals (Sweden)

    Sheng-Ta Lee

    2013-01-01

    Full Text Available As the conventional means of analyzing the similarity between a query sequence and database sequences, the Smith-Waterman algorithm is feasible for a database search owing to its high sensitivity. However, this algorithm is still quite time consuming. CUDA programming can improve computations efficiently by using the computational power of massive computing hardware as graphics processing units (GPUs. This work presents a novel Smith-Waterman algorithm with a frequency-based filtration method on GPUs rather than merely accelerating the comparisons yet expending computational resources to handle such unnecessary comparisons. A user friendly interface is also designed for potential cloud server applications with GPUs. Additionally, two data sets, H1N1 protein sequences (query sequence set and human protein database (database set, are selected, followed by a comparison of CUDA-SW and CUDA-SW with the filtration method, referred to herein as CUDA-SWf. Experimental results indicate that reducing unnecessary sequence alignments can improve the computational time by up to 41%. Importantly, by using CUDA-SWf as a cloud service, this application can be accessed from any computing environment of a device with an Internet connection without time constraints.

  13. Nutritional effects of culture media on mycoplasma cell size and removal by filtration.

    Science.gov (United States)

    Folmsbee, Martha; Howard, Glenn; McAlister, Morven

    2010-03-01

    Careful media filtration prior to use is an important part of a mycoplasma contamination prevention program. This study was conducted to increase our knowledge of factors that influence efficient filtration of mycoplasma. The cell size of Acholeplasma laidlawii was measured after culture in various nutritional conditions using scanning electron microscopy. The maximum cell size changed, but the minimum cell size remained virtually unchanged and all tested nutritional conditions resulted in a population of cells smaller than 0.2 microm. Culture in Tryptic Soy Broth (TSB) resulted in an apparent increase in the percentage of very small cells which was not reflected in increased penetration of non-retentive 0.2 microm rated filters. A. laidlawii cultured in selected media formulations was used to challenge 0.2 microm rated filters using mycoplasma broth base as the carrier fluid. We used 0.2 microm rated filters as an analytical tool because A. laidlawii is known to penetrate 0.2 microm filters and the degrees of penetration can be compared. Culture of A. laidlawii in TSB resulted in cells that did not penetrate 0.2 microm rated filters to the same degree as cells cultured in other media such as mycoplasma broth or in TSB supplemented with 10% horse serum. (c) 2009 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

  14. Inorganic geochemistry and redox dynamics in bank filtration settings.

    Science.gov (United States)

    Farnsworth, Claire E; Hering, Janet G

    2011-06-15

    Bank filtration induces flow of surface water through a hydraulically connected aquifer by excess pumping from a production well in the aquifer. This review presents the four main geochemical processes relevant for inorganic geochemistry, with a focus on iron (Fe) and manganese (Mn), during bank filtration: reduction near the bank, oxidation near the production well, carbonate dissolution, and sorption to aquifer materials. Physical and transport processes affect these geochemical processes and influence the redox state of the infiltrate. The presence of Fe and Mn in bank infiltrate is directly related to its redox status and can necessitate drinking water treatment after extraction. Long-term, in situ sequestration of Fe and Mn requires precipitation of oxide or carbonate solids, since a sorption front can breakthrough at the production well.

  15. NASA Lunar Dust Filtration and Separations Workshop Report

    Science.gov (United States)

    Agui, Juan H.; Stocker, Dennis P.

    2009-01-01

    NASA Glenn Research Center hosted a 2.5-day workshop, entitled "NASA Lunar Dust Filtration and Separations Workshop" at the Ohio Aerospace Institute in Cleveland, Ohio, on November 18 to 20, 2008. The purpose of the workshop was to address the issues and challenges of particulate matter removal from the cabin atmospheres in the Altair lunar lander, lunar habitats, and in pressurized rovers. The presence of lunar regolith dust inside the pressurized volumes was a theme of particular interest. The workshop provided an opportunity for NASA, industry experts, and academia to identify and discuss the capabilities of current and developing air and gas particulate matter filtration and separations technologies as they may apply to NASA s needs. A goal of the workshop was to provide recommendations for strategic research areas in cabin atmospheric particulate matter removal and disposal technologies that will advance and/or supplement the baseline approach for these future lunar surface exploration missions.

  16. Biological filtration for removal of arsenic from drinking water.

    Science.gov (United States)

    Pokhrel, Damodar; Viraraghavan, Thiruvenkatachari

    2009-04-01

    The main objective of the study was to find a suitable iron to arsenic ratio in water to reduce arsenic to 5 microg/L or lower through sand filtration. Experiments were conducted by varying the quantity of iron(II) while keeping the arsenic concentration at 100 microg/L. A mixture of iron (II) and arsenic at different ratios (10:1, 20:1, 30:1 and 40:1) was pumped to the sand filters in a down flow mode and effluent arsenic and iron were analyzed. It was found that a ratio of iron to arsenic of 40:1 was necessary to ensure an effluent arsenic concentration of 5 microg/L or lower. Iron in the filtrate was found to be below 0.1 mg/L at all times.

  17. Carbon Nanotube Membranes: Synthesis, Properties, and Future Filtration Applications

    Science.gov (United States)

    Rashid, Md. Harun-Or; Ralph, Stephen F.

    2017-01-01

    Over the course of the past decade, there has been growing interest in the development of different types of membranes composed of carbon nanotubes (CNTs), including buckypapers and composite materials, for an ever-widening range of filtration applications. This article provides an overview of how different types of CNT membranes are prepared and the results obtained from investigations into their suitability for different applications. The latter involve the removal of small particles from air samples, the filtration of aqueous solutions containing organic compounds and/or bacteria, and the separation of individual liquids present in mixtures. A growing number of reports have demonstrated that the incorporation of CNTs into composite membranes confers an improved resistance to fouling caused by biomacromolecules and bacteria. These results are discussed, along with evidence that demonstrates it is possible to further reduce fouling by taking advantage of the inherent conductivity of composite membranes containing CNTs, as well as by using different types of electrochemical stimuli. PMID:28468314

  18. Submicrometre particle filtration with a dc activated plasma textile

    Science.gov (United States)

    Rasipuram, S. C.; Wu, M.; Kuznetsov, I. A.; Kuznetsov, A. V.; Levine, J. F.; Jasper, W. J.; Saveliev, A. V.

    2014-01-01

    Plasma textiles are novel fabrics incorporating the advantages of cold plasma and low-cost non-woven or woven textile fabrics. In plasma textiles, electrodes are integrated into the fabric, and a corona discharge is activated within and on the surface of the fabric by applying high voltages above 10 kV between the electrodes. When the plasma textile is activated, submicrometre particles approaching the textile are charged by the deposition of ions and electrons produced by the corona, and then collected by the textile material. A stable plasma discharge was experimentally verified on the surface of the textile that was locally smooth but not rigid. A filtration efficiency close to 100% was observed in experiments conducted on salt particles with diameters ranging from 50 to 300 nm. Unlike conventional fibrous filters, the plasma textile provided uniform filtration in this range, without exhibiting a maximum particle penetration size.

  19. The use of an air filtration system in podiatry clinics.

    Science.gov (United States)

    McLarnon, Nichola; Burrow, Gordon; Maclaren, William; Aidoo, Kofi; Hepher, Mike

    2003-06-01

    A small-scale study was conducted to ascertain the efficiency and effectiveness of an air filtration system for use in podiatry/chiropody clinics (Electromedia Model 35F (A), Clean Air Ltd, Scotland, UK). Three clinics were identified, enabling comparison of data between podiatry clinics in the West of Scotland. The sampling was conducted using a portable Surface Air Sampler (Cherwell Laboratories, Bicester, UK). Samples were taken on two days at three different times before and after installation of the filtration units. The global results of the study indicate the filter has a statistically significant effect on microbial counts, with an average percentage decrease of 65%. This study is the first time, to the authors' knowledge, such a system has been tested within podiatric practice.

  20. Photodynamic modulation of wound healing in glaucoma filtration surgery.

    Science.gov (United States)

    Jordan, J F; Diestelhorst, M; Grisanti, S; Krieglstein, G K

    2003-07-01

    To report a clinical pilot study investigating photodynamic therapy (PDT) in combination with glaucoma filtration surgery. BCECF-AM was used as the photosensitising substance. The clinical safety and tolerability of BCECF-AM, and its efficacy in controlling postoperative intraocular pressure (IOP) were assessed. Before trabeculectomy (TE), 42 consecutive eyes of 36 glaucoma patients received one subconjunctival injection of 80 micro g BCECF-AM (2,7,-bis- (2-carboxyethyl) -5- (and-6) -carboxy-fluorescein, acetoxymethyl-ester) followed by an intraoperative illumination with blue light (lambda = 450-490 nm) for 8 minutes. Antifibrotic efficacy was established as postoperative IOP reduction of >20% and/or an IOP constantly toxicity, no uveitis, and no endophthalmitis. This method is a new approach in modulating postoperative wound healing in human eyes undergoing glaucoma filtration surgery. The data of the first human eyes combining TE with PDT underline the clinical safety of this method and its possible potential to prolong bleb survival.

  1. Riverbank filtration: an efficient and economical water treatment technology

    OpenAIRE

    Jaramillo uribe, Marcela

    2012-01-01

    Riverbank Filtration (RBF) is a water treatment technology that consists of extracting water from rivers by pumping wells located in the adjacent alluvial aquifer. During the underground passage, a series of physical, chemical, and biological processes take place, improving the quality of the surface water, substituting or reducing conventional drinking water treatment. Despite its extensive use in Europe and its emerging use in the United States, there are no scientific publications related ...

  2. Removal of metal ions using dead-end filtration

    African Journals Online (AJOL)

    2005-07-03

    Jul 3, 2005 ... It consists of a compressor, pressure gauge, filtration kit with a nylon membrane having a pore size of 0.1 μm and a meas- uring cylinder. Compressed air at a pressure of 2.068x105 N·m-2. (30 psi), measured using a pressure gauge, acted as the driving. * To whom all correspondence should be addressed.

  3. Optimal insider control and semimartingale decompositions under enlargement of filtration

    OpenAIRE

    Øksendal, Bernt; Draouil, Olfa

    2015-01-01

    We combine stochastic control methods, white noise analysis, and Hida–Malliavin calculus applied to the Donsker delta functional to obtain explicit representations of semimartingale decompositions under enlargement of filtrations. Some of the expressions are more explicit than previously known. The results are illustrated by examples. This is the Author’s Original Manuscript of an article published by Taylor & Francis in Stochastic Analysis and Applications on 01 Sep 2016, available onlin...

  4. Symmetries and exact solutions of fractional filtration equations

    Science.gov (United States)

    Gazizov, Rafail K.; Kasatkin, Alexey A.; Lukashchuk, Stanislav Yu.

    2017-11-01

    Few fractional differential models of fluid flow through porous medium are considered. We use several modifications of Darcy's law that contain time-and space-fractional derivatives corresponding to memory or non-local effects in filtration. Symmetry properties of the resulting nonlinear anomalous diffusion-type equations are analyzed and new group-invariant solutions are constructed. In particular, we obtain fractional analogues of so-called blow-up solutions.

  5. Sand intermittent filtration technology for safer domestic sewage ...

    African Journals Online (AJOL)

    Maximum pollution reduction potential of intermittent filtration bed was recorded at 2 feet depth of sand and soil mixture at ratio of 3:1. Percentage of pollution reducing potential was found in CO2 83.4%, BOD 72.5%, COD 69.9%, Total alkalinity 37.9%, Total solids 88.5%, Total dissolved solids 86.1%, Total suspended solids ...

  6. Modeling Manganese Sorption and Surface Oxidation During Filtration

    OpenAIRE

    Bierlein, Kevin Andrew

    2012-01-01

    Soluble manganese (Mn) is a common contaminant in drinking water sources. High levels of Mn can lead to aesthetic water quality problems, necessitating removal of Mn during treatment to minimize consumer complaints. Mn may be removed during granular media filtration by the â natural greensand effect,â in which soluble Mn adsorbs to manganese oxide-coated (MnOx(s)) media and is then oxidized by chlorine, forming more manganese oxide. This research builds on a previous model developed by Mer...

  7. Effects of applying trichostatin A on filtration bleb after filtering surgery in rabbits

    Directory of Open Access Journals (Sweden)

    Xiao-Yan Li

    2014-10-01

    Full Text Available AIM: To observe the morphologic changes of of filtration blebs after trichostatin A treatment in an experimental glaucoma filtration surgery(GFS.METHODS: Subconjunctival injection TSA, mitomycin C(MMCand PBS during the filtering surgery in rabbits. The morphologic changes of filtration blebs were evaluated by Krofeld score method postoperatively days 3, 7, 14, 21, and 28. RESULTS: TSA induced filteation bleds were elevated diffusely within 14d and cystic blebs formed 28d, filtration bleb score was significantly higher in TSA group than that in PBS group.CONCLUSION: TSA can keep the aqueous humor outflow by inhibiting scar formation and prolong the existence of the filtration bleb.

  8. Derivation of total filtration thickness for diagnostic x-ray source assembly

    OpenAIRE

    Sekimoto, Michiharu; Katoh, Yoh

    2016-01-01

    The method defined by the IEC 60522 for determining the inherent filtration of an x-ray source device is applicable only for a limited range of tube voltage. Because the users cannot legally remove the x-ray movable diaphragm of the x-ray source device, total filtration, which is the sum of the additional filtration diaphragm movable for specific filtration and x-ray, cannot be measured. We develop a method for simply obtaining the total filtration for different tube voltage values.Total filt...

  9. Computational fluid dynamics of fish gill rakers during crossflow filtration.

    Science.gov (United States)

    Cheer, Angela; Cheung, Samson; Hung, Tien-Chieh; Piedrahita, Raul H; Sanderson, S Laurie

    2012-04-01

    We study crossflow filtration mechanisms in suspension-feeding fishes using computational fluid dynamics to model fluid flow and food particle movement in the vicinity of the gill rakers. During industrial and biological crossflow filtration, particles are retained when they remain suspended in the mainstream flow traveling across the filter surface rather than traveling perpendicularly to the filter. Here we identify physical parameters and hydrodynamic processes that determine food particle movement and retention inside the fish oral cavity. We demonstrate how five variables affect flow patterns and particle trajectories: (1) flow speed inside the fish oral cavity, (2) incident angle of the flow approaching the filter, (3) dimensions of filter structures, (4) particle size, and (5) particle density. Our study indicates that empirical experiments are needed to quantify flow parameters inside the oral cavity, and morphological research is needed to quantify dimensions of the filter apparatus such as gill rakers, the gaps between rakers, and downstream barriers. Ecological studies on suspension-feeding fishes are also needed to quantify food particle size and density, as these variables can affect particle retention due to hydrodynamic processes during crossflow filtration.

  10. Filtration of sunflower oil in the field of vibroacoustic effects

    Directory of Open Access Journals (Sweden)

    S. A. Bredikhin

    2017-01-01

    Full Text Available Purification of crude unrefined sunflower oil along with the removal of primary oxidation products is an urgent task to remove the solid constituents formed during the processing of sunflower seeds. All of them irrespective of the chemical composition negatively affect the quality of the food product and, over time, saturate the oil with coagulants that affect its organoleptic and physico-mechanical characteristics. The problem of cleaning unrefined sunflower oil by filtration with the use of vibroacoustic action is considered. The calculation scheme of the process is given, and an experimental setup has been developed that makes it possible to vary the angle of inclination of the filter element. The research of sunflower oil filtration in the field of vibroacoustic impact is carried out. In the study, a decision was made to expand the energy effects to create a cumulative system in the liquid medium that improves the hydrodynamic situation at the scale of the oil purification plant. It is established that the process speed can be intensified by creating additional microflows that provide an active influence on the motion of liquid, gas and solid particles. The results are obtained, which testify to the effectiveness of the use of vibroacoustic effects during the filtration of sunflower oil.

  11. Severe loss and recovery of vision after glaucoma filtration surgery.

    Science.gov (United States)

    Chen, Brian H; Gordon, Hillary B; Shah, Chirag P; Spaeth, George L

    2012-03-01

    To report a case of sudden, severe, unexplained, bilateral loss of vision after glaucoma filtration surgery in both eyes; the vision returned 2 months later. The clinical records of the patient were reviewed retrospectively. Observations were made and collated as the case progressed. A 25-year-old man previously diagnosed with poorly controlled, far-advanced, juvenile-onset primary open-angle glaucoma underwent bilateral guarded filtration procedures. Preoperative visual acuity was 20/40 in the right eye and 20/100 in the left eye. After the procedure visual acuity was severely diminished to no light perception in the right eye and light perception in the left eye. There was no apparent cause for the visual reduction other than the decrease in intraocular pressure caused by the surgery. Two months postoperatively, the patient had visual acuity of 20/80 in the right eye and 20/200 in the left eye. Ten months postoperatively, visual acuity was 20/70 in the right eye and 20/200 in the left eye. Twenty-three months postoperatively, visual acuity was 20/100 in the right eye and 20/200 in the left eye. This case provides evidence for the potential reversibility of severe visual loss after glaucoma filtration surgery.

  12. Vulnerability of bank filtration systems to climate change.

    Science.gov (United States)

    Sprenger, C; Lorenzen, G; Hülshoff, I; Grützmacher, G; Ronghang, M; Pekdeger, A

    2011-01-15

    Bank filtration (BF) is a well established and proven natural water treatment technology, where surface water is infiltrated to an aquifer through river or lake banks. Improvement of water quality is achieved by a series of chemical, biological and physical processes during subsurface passage. This paper aims at identifying climate sensitive factors affecting bank filtration performance and assesses their relevance based on hypothetical 'drought' and 'flood' climate scenarios. The climate sensitive factors influencing water quantity and quality also have influence on substance removal parameters such as redox conditions and travel time. Droughts are found to promote anaerobic conditions during bank filtration passage, while flood events can drastically shorten travel time and cause breakthrough of pathogens, metals, suspended solids, DOC and organic micropollutants. The study revealed that only BF systems comprising an oxic to anoxic redox sequence ensure maximum removal efficiency. The storage capacity of the banks and availability of two source waters renders BF for drinking water supply less vulnerable than surface water or groundwater abstraction alone. Overall, BF is vulnerable to climate change although anthropogenic impacts are at least as important. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. Filtration Parameters Influencing Circulating Tumor Cell Enrichment from Whole Blood

    Science.gov (United States)

    Beck, Markus; Terstappen, Leon W. M. M.

    2013-01-01

    Filtration can achieve circulating tumor cell (CTC) enrichment from blood. Key parameters such as flow-rate, applied pressure, and fixation, vary largely between assays and their influence is not well understood. Here, we used a filtration system, to monitor these parameters and determine their relationships. Whole blood, or its components, with and without spiked tumor cells were filtered through track-etched filters. We characterize cells passing through filter pores by their apparent viscosity; the viscosity of a fluid that would pass with the same flow. We measured a ratio of 5·104∶102∶1 for the apparent viscosities of 15 µm diameter MDA-231 cells, 10 µm white cells and 90 fl red cells passing through a 5 µm pore. Fixation increases the pressure needed to pass cells through 8 µm pores 25-fold and halves the recovery of spiked tumor cells. Filtration should be performed on unfixed samples at a pressure of ∼10 mbar for a 1 cm2 track-etched filter with 5 µm pores. At this pressure MDA-231 cells move through the filter in 1 hour. If fixation is needed for sample preservation, a gentle fixative should be selected. The difference in apparent viscosity between CTC and blood cells is key in optimizing recovery of CTC. PMID:23658615

  14. Ultra-filtration measurement using CT imaging technology

    Energy Technology Data Exchange (ETDEWEB)

    Lu Junfeng [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No.2 Beiyitiao Street, Zhongguancun, Haidian District, Beijing, 100190 (China); Lu Wenqiang, E-mail: junfenglu@mail.ipc.ac.c [Graduate University of Chinese Academy of Sciences, No.19A Yuquan Road, Shijingshan District, Beijing, 100049 (China)

    2009-02-01

    As a functional unit in the hemodialysis process, dialyzer captured quite a few medical research interests since 1980s. In the design of dialyzer or in the ongoing hemodialysis process, to estimate the ultra-filtration amount of a dialyzer, the sideway loss of the running blood flow through hollow fibers or filtration channels should be measured. This further leads to the measurement of the blood flow inside the dialyzer. For this measurement, a non-invasive method is highly desired because of the high-dense bundled hollow fibers or packed channels inside the dialyzer. As non-invasive measurement tools, CT (Computed Tomography) technologies were widely used for tissue, bone, and cancerous clinical analyses etc .... Thus, in this paper, a CT system is adopted to predict the blood flow inside a hollow fiber dialyzer. In view of symmetric property of the hollow fiber dialyzer, the largest cutting plane that parallels to the cylindrical dialyzer was analyzed by the CT system dynamically. And then, a noninvasive image analysis method used to predict the ultra-filtration amount is proposed.

  15. GPS Data Filtration Method for Drive Cycle Analysis Applications

    Energy Technology Data Exchange (ETDEWEB)

    Duran, A.; Earleywine, M.

    2013-02-01

    When employing GPS data acquisition systems to capture vehicle drive-cycle information, a number of errors often appear in the raw data samples, such as sudden signal loss, extraneous or outlying data points, speed drifting, and signal white noise, all of which limit the quality of field data for use in downstream applications. Unaddressed, these errors significantly impact the reliability of source data and limit the effectiveness of traditional drive-cycle analysis approaches and vehicle simulation software. Without reliable speed and time information, the validity of derived metrics for drive cycles, such as acceleration, power, and distance, become questionable. This study explores some of the common sources of error present in raw onboard GPS data and presents a detailed filtering process designed to correct for these issues. Test data from both light and medium/heavy duty applications are examined to illustrate the effectiveness of the proposed filtration process across the range of vehicle vocations. Graphical comparisons of raw and filtered cycles are presented, and statistical analyses are performed to determine the effects of the proposed filtration process on raw data. Finally, an evaluation of the overall benefits of data filtration on raw GPS data and present potential areas for continued research is presented.

  16. Removal of benzocaine from water by filtration with activated carbon

    Science.gov (United States)

    Howe, G.E.; Bills, T.D.; Marking, L.L.

    1990-01-01

    Benzocaine is a promising candidate for registration with the U.S. Food and Drug Administration for use as an anesthetic in fish culture, management, and research. A method for the removal of benzocaine from hatchery effluents could speed registration of this drug by eliminating requirements for data on its residues, tolerances, detoxification, and environmental hazards. Carbon filtration effectively removes many organic compounds from water. This study tested the effectiveness of three types of activated carbon for removing benzocaine from water by column filtration under controlled laboratory conditions. An adsorptive capacity was calculated for each type of activated carbon. Filtrasorb 400 (12 x 40 mesh; U.S. standard sieve series) showed the greatest capacity for benzocaine adsorption (76.12 mg benzocaine/g carbon); Filtrasorb 300 (8 x 30 mesh) ranked next (31.93 mg/g); and Filtrasorb 816 (8 x 16 mesh) absorbed the least (1.0 mg/g). Increased adsorptive capacity was associated with smaller carbon particle size; however, smaller particle size also impeded column flow. Carbon filtration is a practical means for removing benzocaine from treated water.

  17. Are vacuum-filtrated reduced graphene oxide membranes symmetric?

    KAUST Repository

    Tang, Bo

    2015-12-02

    Graphene or reduced graphene oxide (rGO) membrane-based materials are promising for many advanced applications due to their exceptional properties. One of the most widely used synthesis methods for rGO membranes is vacuum filtration of graphene oxide (GO) on a filter membrane, followed by reduction, which shows great advantages such as operational convenience and good controllability. Despite vacuum-filtrated rGO membranes being widely used in many applications, a fundamental question is overlooked: are the top and bottom surfaces of the membranes formed at the interfaces with air and with the filter membrane respectively symmetric or asymmetric? This work, for the first time, reports the asymmetry of the vacuum-filtrated rGO membranes and discloses the filter membranes’ physical imprint on the bottom surface of the rGO membrane, which takes place when the filter membrane surface pores have similar dimension to GO sheets. This result points out that the asymmetric surface properties should be cautiously taken into consideration while designing the surface-related applications for GO and rGO membranes.

  18. Centrifugal Filtration System for Severe Accident Source Term Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shu Chang; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The objective of this paper is to present the conceptual design of a filtration system that can be used to process airborne severe accident source term. Reactor containment may lose its structural integrity due to over-pressurization during a severe accident. This can lead to uncontrolled radioactive releases to the environment. For preventing the dispersion of these uncontrolled radioactive releases to the environment, several ways to capture or mitigate these radioactive source term releases are under investigation at KAIST. Such technologies are based on concepts like a vortex-like air curtain, a chemical spray, and a suction arm. Treatment of the radioactive material captured by these systems would be required, before releasing to environment. For current filtration systems in the nuclear industry, IAEA lists sand, multi-venturi scrubber, high efficiency particulate arresting (HEPA), charcoal and combinations of the above in NS-G-1-10, 4.143. Most if not all of the requirements of the scenario for applying this technology near the containment of an NPP site and the environmental constraints were analyzed for use in the design of the centrifuge filtration system.

  19. Electrospun Carbon Nanofiber Membranes for Filtration of Nanoparticles from Water

    Directory of Open Access Journals (Sweden)

    Mirko Faccini

    2015-01-01

    Full Text Available Nowadays, hundreds of consumer products contain metal and metal oxide nanoparticles (NP; this increases the probability of such particles to be released to natural waters generating a potential risk to human health and the environment. This paper presents the development of efficient carboneous nanofibrous membranes for NP filtration from aqueous solutions. Free-standing carbon nanofiber (CNF mats with different fiber size distribution ranging from 126 to 554 nm in diameter were produced by electrospinning of polyacrylonitrile (PAN precursor solution followed by thermal treatment. Moreover, tetraethoxyorthosilicate was added to provide flexibility and increase the specific surface area of the CNF. The resulting membranes are bendable and mechanically strong enough to withstand filtration under pressure or vacuum. The experimental results of filtration revealed that the fabricated membranes could efficiently reject nanoparticles of different types (Au, Ag, and TiO2 and size (from 10 to 100 nm in diameter from aqueous solutions. It is worth mentioning that the removal of Ag NP with diameters as small as 10 nm was close to 100% with an extremely high flux of 47620 L m−2 h−1 bar−1.

  20. Preliminary evaluation of fungicidal and termiticidal activities of filtrates from biomass slurry fuel production.

    Science.gov (United States)

    Kartal, S N; Imamura, Y; Tsuchiya, F; Ohsato, K

    2004-10-01

    Biomass slurry fuel (BSF) production has recently been developed as a natural energy for the conversion of solid biomass into fuel. In addition to using fuel, filtrates from BSF production may also serve a chemical source with several organic compounds. There is an increasing interest in the research and application of biomass-based filtrates. In this study, fungicidal and termiticidal properties of filtrates from BSF production using sugi (Cryptomeria japonica) and acacia (Acacia mangium) wood were evaluated in laboratory decay and termite resistance tests. Wood blocks treated with the filtrates showed increased resistance against brown-rot fungus, Fomitopsis palustris. However the filtrates from sugi wood processed at 270 degrees C which contained less phenolic compounds than the other filtrates were effective against white-rot fungus, Trametes versicolor. Phenolic compounds of filtrates seemed to play a role in the decay resistance tests however the filtrates did not increase the durability of the wood blocks against subterranean termites Coptotermes formosanus. Despite high acetic and lactic acid content of the filtrates, vanillin content of the filtrates may have served as an additional food source and promoted termite attack. It can be concluded that filtrates with phenolic compounds from lignin degradation during BSF production can be considered for targeted inhibition of brown-rot.

  1. Preliminary evaluation of fungicidal and termiticidal activities of filtrates from biomass slurry fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Kartal, S.N. [Istanbul University (Turkey). Forestry Faculty; Imamura, Y. [Kyoto University (Japan). Wood Research Institute; Tsuchiya, F.; Ohsato, K. [JGC Corporation, Yokohama (Japan)

    2004-10-01

    Biomass slurry fuel (BSF) production has recently been developed as a natural energy for the conversion of solid biomass into fuel. In addition to using fuel, filtrates from BSF production may also serve a chemical source with several organic compounds. There is an increasing interest in the research and application of biomass-based filtrates. In this study, fungicidal and termiticidal properties of filtrates from BSF production using sugi (Cryptomeria japonica) and acacia (Acacia mangium) wood were evaluated in laboratory decay and termite resistance tests. Wood blocks treated with the filtrates showed increased resistance against brown-rot fungus, Formitopsis palustris. However the filtrates from sugi wood processed at 270{sup o}C which contained less phenolic compounds than the other filtrates were effective against white-rot fungus, Trametes versicolor. Phenolic compounds of filtrates seemed to play a role in the decay resistance tests however the filtrates did not increase the durability of the wood blocks against subterranean termites Coptotermes formosanus. Despite high acetic and lactic acid content of the filtrates, vanillin content of the filtrates may have served as an additional food source and promoted termite attack. It can be concluded that filtrates with phenolic compounds from lignin degradation during BSF production can be considered for targeted inhibition of brown-rot. (author)

  2. Uptake of wheel-filtration among clients of a supervised injecting facility: Can structured education work?

    Science.gov (United States)

    Steele, Maureen; Silins, Edmund; Flaherty, Ian; Hiley, Sarah; van Breda, Nick; Jauncey, Marianne

    2018-01-01

    Wheel-filtration of pharmaceutical opioid tablets is a recognised harm reduction strategy, but uptake of the practice among people who inject drugs is low. The study aimed to: (i) examine perceptions of filtration practices; (ii) provide structured education on wheel-filtration; and (iii) assess uptake of the practice. Frequent opioid tablet injectors (n = 30) attending a supervised injecting facility in Sydney, Australia, received hands-on instruction on wheel-filtration based on recommended practice. Pre-education, post-education and follow-up questionnaires were administered. Wheel-filtration was generally regarded as better than cotton-filtration (the typical method) in terms of perceived effects on health, ease of use and overall drug effect. Sixty-eight percent of those who said they would try wheel-filtration after the education had actually done so. Of those who usually used cotton-filtration, over half (60%) had used wheel-filtration two weeks later. Uptake of safer preparation methods for pharmaceutical opioid tablets increases after structured education in wheel-filtration. Findings suggest that SIFs are an effective site for this kind of education. Supervised injecting facility workers are uniquely positioned to provide harm reduction education at the time of injection. [Steele M, Silins E, Flaherty I, Hiley S, van Breda N, Jauncey M. Uptake of wheel-filtration among clients of a supervised injecting facility: Can structured education work? Drug Alcohol Rev 2018;37:116-120]. © 2017 Australasian Professional Society on Alcohol and other Drugs.

  3. Measuring of filtration efficiency of nonwoven textiles in volume from scattered light by seeding particles

    Directory of Open Access Journals (Sweden)

    Sidlof P.

    2013-04-01

    Full Text Available This paper deals with the method which calculates a filtration efficiency of nonwoven textiles from scattered light intensity by seeding particles. Thefiltration efficiency is commonly measured by particle counters. Samples of liquid or gas are taken during a test in front of and behind a filtration material. The concentration of particles is measured and the filtration efficiency is calculated. The filtration efficiency does not have to be uniform in itswhole surface. The uniformity of filtration is another indicator of a quality of filtration materials. Measurements described in this article were performed on a water filtration setup which enables optical access to the place where the filtration material is mounted. Pictures of illuminated seeding particles are made by a laser sheet and a camera. Visualisation of the filtration process enables measuring of the efficiency of separation versus time and also versus two-dimensional position in case of use of a traverse mechanism. The filtration textiles were tested by 1 μm seeding particles. Mean value of light intensity and number of bright pixels in evaluative areas during image analysis were obtained. On the basis of these data, the filtration efficiency iscalculated. The best image analysis method was chosen.

  4. Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast.

    Science.gov (United States)

    Gonçalves, Andréa; Rollo, João Manuel Domingos de Almeida; Gonçalves, Marcelo; Haiter Neto, Francisco; Bóscolo, Frab Norberto

    2004-01-01

    This study evaluated the performance of aluminum-copper alloy filtration, without the original aluminum filter, for dental radiography in terms of x-ray energy spectrum, air kerma rate and image quality. Comparisons of various thicknesses of aluminum-copper alloy in three different percentages were made with aluminum filtration. Tests were conducted on an intra-oral dental x-ray machine and were made on mandible phantom and on step-wedge. Depending on the thickness of aluminum-copper alloy filtration, the beam could be hardened and filtrated. The use of the aluminum-copper alloy filter resulted in reductions in air kerma rate from 8.40% to 47.33%, and indicated the same image contrast when compared to aluminum filtration. Aluminum-copper alloy filtration may be considered a good alternative to aluminum filtration.

  5. [Evaluation of preoperative anxiety in patients requiring glaucoma filtration surgery].

    Science.gov (United States)

    Lemaitre, S; Blumen-Ohana, E; Akesbi, J; Laplace, O; Nordmann, J-P

    2014-01-01

    Preoperative anxiety is often expressed by patients requiring filtration surgery for their glaucoma. So far, there has been no scale for screening this group of patients for preoperative anxiety. The Amsterdam Preoperative Anxiety and Information Scale (APAIS) is a self-evaluation questionnaire which has been used in specialties other than ophthalmology and which makes it possible to identify the adult patients with a high level of preoperative anxiety over an upcoming surgical procedure. The purpose of this study is to estimate the preoperative anxiety in glaucoma patients requiring filtration surgery. We performed a prospective study of 36 adult patients with chronic glaucoma not responding to medical treatment and who were about to undergo filtration surgery (trabeculectomy or deep sclerectomy). The APAIS questionnaire was given to the patients after discussing the indication for surgery. A global anxiety score (ranging from 4 to 20) above 10 defined patients with a high level of preoperative anxiety. We attempted to identify among these patients the factors related to filtration surgery which caused them anxiety (lack of control of intraocular pressure, risk of blindness, presence of the filtering bleb). In our sample of patients, we found that glaucoma was a source of anxiety. That was also true for the surgical procedure, though most patients believe that once the decision had been made, their psychological status was not modified by the upcoming procedure. The patient-clinician relationship is important in any chronic disease, all the more so in glaucoma, since this disease remains asymptomatic for a long time. When filtration surgery is necessary, the patients are going to express less preoperative anxiety if they trust their physician and if individualized information has been given to them The French version of the APAIS is a quick scale, easily completed, that can be recommended for evaluating anxiety and patients' need for information prior to filtering

  6. CROSSFLOW FILTRATION: EM-31, WP-2.3.6

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M.; Nash, C.; Poirier, M.

    2011-02-01

    In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing crossflow equipment. The Savannah River National Laboratory (SRNL) performed some of those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Crossflow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate solutions. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Integrated Salt Disposition Process and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the crossflow filter feed flow rate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and crossflow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed several

  7. Bench-Scale Filtration Testing in Support of the Pretreatment Engineering Platform (PEP)

    Energy Technology Data Exchange (ETDEWEB)

    Billing, Justin M.; Daniel, Richard C.; Kurath, Dean E.; Peterson, Reid A.

    2009-09-28

    Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.” The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP testing program specifies that bench-scale testing is to be performed in support of specific operations, including filtration, caustic leaching, and oxidative leaching.

  8. Subscale Validation of the Subsurface Active Filtration of Exhaust (SAFE) Approach to the NTP Ground Testing

    Science.gov (United States)

    Marshall, William M.; Borowski, Stanley K.; Bulman, Mel; Joyner, Russell; Martin, Charles R.

    2015-01-01

    Nuclear thermal propulsion (NTP) has been recognized as an enabling technology for missions to Mars and beyond. However, one of the key challenges of developing a nuclear thermal rocket is conducting verification and development tests on the ground. A number of ground test options are presented, with the Sub-surface Active Filtration of Exhaust (SAFE) method identified as a preferred path forward for the NTP program. The SAFE concept utilizes the natural soil characteristics present at the Nevada National Security Site to provide a natural filter for nuclear rocket exhaust during ground testing. A validation method of the SAFE concept is presented, utilizing a non-nuclear sub-scale hydrogen/oxygen rocket seeded with detectible radioisotopes. Additionally, some alternative ground test concepts, based upon the SAFE concept, are presented. Finally, an overview of the ongoing discussions of developing a ground test campaign are presented.

  9. A Risk-based Approach to Setting Sterile Filtration Bioburden Limits.

    Science.gov (United States)

    Yang, Harry; Li, Na; Chang, Stephen

    2013-01-01

    Microbial control during the drug substance and drug product manufacturing process is critical for ensuring product quality and safety. For sterile biological drug products (finished dosage forms) typically manufactured by sterile filtration followed by aseptic processing, control of the microbial load at the sterile filtration step is an important component of the overall microbial control strategy. Both FDA and EMA regulatory guidelines stipulate that a maximum acceptable bioburden level, which is referred to as a pre-filtration bioburden level in this paper, should be stated at the point immediately prior to the sterile filtration step. The EMA guideline further states that a bioburden limit of no more than 10 colony-forming units (CFU) per 100 mL will be considered acceptable in most situations. The EMA guideline also states that a pre-filtration sample volume of less than 100 mL may be tested if justified. This paper introduces a risk-based method to establish pre-filtration bioburden acceptance levels and alternative test volumes. The relationship between bioburden risk, pre-filtration bioburden test limits, and sterile filtration process parameters, such as filtration volume, filter surface area, and microbial retention capacity of the sterilizing filter, was statistically determined. Taking into account the batch filtration volume, it is shown that pre-filtration bioburden test volumes and acceptance limits other than 10 CFU/100 mL may be justified, without compromise to sterility assurance. In the manufacturing of sterile medicinal products, good manufacturing practice requires that bioburden be monitored before the final sterilization filtration step. High bioburden increases the challenge to the sterilizing filter and may also lead to other quality issues. Therefore a pre-filtration bioburden limit should be established. This paper introduces a risk-based method to establish such limit which may be different from what is recommended in regulatory

  10. Optical measurements of lung microvascular filtration coefficient using polysulfone fibers.

    Science.gov (United States)

    Klaesner, J W; Roselli, R J; Evans, S; Pou, N A; Parker, R E; Tack, G; Parham, M

    1994-01-01

    Lung fluid balance, which is governed by the product of net transvascular pressure difference and lung filtration coefficient, can be altered in pulmonary diseases. A simple measurement of the lung filtration coefficient (Kfc) would be clinically useful and has been examined by several researchers. Current methods of determining Kfc include gravimetric measurement in isolated lungs and lymph node cannulation, neither of which can be extended to human use. Optical measurements of protein concentration changes in venous blood can be combined with pressure measurements to calculate Kfc. Blood, though, contains red corpuscles, which tend to absorb and scatter light, obscuring these optical measurements. In this study, an optical system was developed in which a polysulfone filter cartridge was used to remove red blood cells before the filtrate was passed through a spectrophotometer. Absorbance changes caused by changes in concentration of albumin labeled with Evans Blue were monitored at 620 nm after venous pressure was elevated by about 13 cm H2O. Optical measurements of Kfc averaged 0.401 +/- 0.074 (ml/min cm H2O 100 g DLW) for an isolated canine lung. Optical measurements of Kfc (0.363 +/- 0.120 ml/min cm H2O 100 g DLW) were made for the first time in an intact, closed chest sheep in which pulmonary pressure was altered by inflating a Foley balloon in the left atrium. We conclude that absorbance and scattering artifacts introduced by red blood cells can be eliminated by first filtering the blood through polysulfone fibers. Kfc measurements using the optical method are similar to values obtained by others using gravimetric methods. Finally, we have demonstrated that the technique can be used to estimate Kfc in an intact animal.

  11. Filtration and clogging of permeable pavement loaded by urban drainage.

    Science.gov (United States)

    Sansalone, J; Kuang, X; Ying, G; Ranieri, V

    2012-12-15

    Permeable pavement, as a sustainable infrastructure material can promote hydrologic restoration, particulate matter (PM) and solute control. However, filtration and commensurate clogging are two aspects of continued interest and discussion. This study quantifies filtration and clogging of cementitious permeable pavement (CPP) for loadings from 50 to 200 mg/L of hetero-disperse sandy-silt PM. The CPP mix design provides a hetero-disperse pore size distribution (PSD)(pore), effective porosity (φ(e)) of 24% and median pore size of 658 μm with a standard deviation of 457 μm. The PM mass separation across the entire particle size distribution (PSD)(PM) exceeds 80%; with complete separation for PM greater than 300 μm and 50% separation for suspended PM. Turbidity is reduced (42-95%), and effluent is below 10 NTU in the first quartile of a loading period. Permeable pavement illustrates reductions in initial (clean-bed) hydraulic conductivity (k(0)) with loading time. For all PM loadings, k(0) (3.1 × 10(-1) mm/s) was reduced to 10(-4) mm/s for runoff loading durations from 100 to 250 h, respectively. Temporal hydraulic conductivity (k) follows exponential profiles. Maintenance by vacuuming and sonication illustrate that 96-99% of k(0) is recovered. Permeable pavement constitutive properties integrated with measured PM loads and a year of continuous rainfall-runoff simulation illustrate k reduction with historical loadings. Study results measure and model filtration and hydraulic conductivity phenomena as well as maintenance requirements of permeable pavement directly loaded by urban drainage. Copyright © 2011. Published by Elsevier Ltd.

  12. Filtration stability of living brush mattresses at navigable waterways

    Science.gov (United States)

    Sokopp, Manuel

    2017-04-01

    According to the guidelines of the Federal Waterways Engineering and Research Institute in Germany, waterway construction buildings, which include soil bioengineering structures, must be stable against soil displacements. Therefore, willow brush mattresses were tested for their filtration stability in a specially developed process which is based on the testing of geotextiles and armourstones used for navigable waterway constructions. In March 2016 willow brush mattresses made of white (Salix alba L.) or basket willows (Salix viminalis L.) were planted in 16 sample boxes, each with a cross-section area of 30x30 cm. For the tests on filtration stability, the upper 20 cm of the box were separated and placed upside down into a device in which the sample box could be flowed through from below. When a water column of 50 cm above the sample was reached, the water outlet was opened so the water flowed through the sample in the opposite direction, thus simulating drawdown. By the measurements of the pressure sensors above and below the sample, the coefficient of permeability k of the rooted soil during drawdown could be calculated. After this hydropeaking cycle, the soil material that was rinsed out through the willow branches was collected, weighed after drying until weight constancy, and compared with the dry mass of the retained soil material to calculate the share of the total mass. These filtration stability tests were carried out directly after planting the sample boxes, as well as one, three and six months afterwards, each test series with four reruns per willow species. Over time, the increasing root penetration resulted in a significant reduction in the permeability and in more retained soil material.

  13. Adsorption and filtration of trace contaminants in aqueous effluents

    Energy Technology Data Exchange (ETDEWEB)

    Irizarry, M.M.; Anthony, D.B.

    1971-04-28

    The removal of trace copper contaminants from aqueous effluents by means of adsorption on ion exchange resins was studied. A semicontinuous, axial filtration device was used to obtain mass transfer data as a function of the operating parameters: flow rate, resin volume and size, temperature, rotational speed, and system geometry. Correlation of data based on power dissipation per unit volume is presented. Operation of the unit involved high product fluxes (1000 to 15,000 gpd/ft/sup 2/) and adsorption efficiencies (90 to 99+%) coupled with low pressure drops (0 to 10 psi).

  14. Analyse du debit de filtration glomerulaire de repos chez des ...

    African Journals Online (AJOL)

    Analyse du debit de filtration glomerulaire de repos chez des joueuses de sports collectifs au Benin. ... Dans le groupe étudié, la valeur moyenne de la créatininémie est de 9,5 ± 1,2 mg/L. Le DFG moyen estimé avec l'équation MDRD (74,2 ± 11,6 mL/min/1,73 m2) était plus bas que celui estimé avec la formule CGc (89,4 ...

  15. Indexing Glomerular Filtration Rate to Body Surface Area

    DEFF Research Database (Denmark)

    Redal-Baigorri, Belén; Rasmussen, Knud; Heaf, James Goya

    2014-01-01

    BACKGROUND: Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals....... We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS: Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA...

  16. Optional splitting formula in a progressively enlarged filtration

    OpenAIRE

    Song, Shiqi

    2012-01-01

    Let $\\mathbb{F}$ be a filtration and $\\tau$ be a random time. Let $\\mathbb{G}$ be the progressive enlargement of $\\mathbb{F}$ with $\\tau$. We study the validity of the following formula, called optional splitting formula : For any $\\mathbb{G}$-optional process $Y$, there exist a $\\mathbb{F}$-optional process $Y'$ and a function $Y"$ defined on $[0,\\infty]\\times(\\mathbb{R}_+\\times\\Omega)$ being $\\mathcal{B}[0,\\infty]\\otimes\\mathcal{O}(\\mathbb{F})$ measurable, such that $$ Y=Y'\\ind_{[0,\\tau)}+Y...

  17. Diabetic nephropathy: glomerular filtration rate and estimated creatinine clearance

    OpenAIRE

    Guimarães, J; Bastos, M.; Melo, M.; Carvalheiro, M.

    2007-01-01

    OBJECTIVE: To assess in diabetic nephropathy, the accuracy of estimated creatinine clearance (calculated with the Cockroft Gault formula) and the clearance of the Tc99m-DTPA, to measure the glomerular filtration rate (GFR). PATIENTS AND METHODS: We analysed the GFR measure by Tc99m-DTPA method and the estimated by the Cockroft Gault formula, in 21 subjects with type 1 or type 2 diabetes. RESULTS: There was a strong positive correlation between the two methods but the Cockroft Gault formula un...

  18. Mud-filtrate correction of sonic logs by fluid substitution

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne

    seismograms generated from velocity versus depth trends recorded as a sonic log in a borehole. Such a comparison is referred to as a well-tie. A high-quality well-tie requires a highquality sonic log, but shallow depth of penetration makes sonic logs sensitive to invasion of mud-filtrate from the borehole...... of wetting phase saturation, and the clay content. When the water saturation is at the irreducible water saturation or higher only the effect of clay on the elastic velocities have a differential effect on the elastic velocities. Mixed saturations are fluid substituted using effective fluid moduli formulated...

  19. Filtration in ultrasonic field; Filtracao em campo ultrassonico

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Inaura Carolina C. da; Cortes, Marcela de Araujo H.; Marques, Jose Jailton [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Dept. de Engenharia Quimica

    2008-07-01

    The production of water associated to the petroleum is an issue of big relevance in exploration areas classified as 'exhausted fields'. The current alternative in practice is the re-injection of the wastewater into the geological formation with the dual purpose of increasing oil recovery and pollution minimization. However, produced water presents several components that make impossible its direct re-injection, requiring a previous treatment. In this context, this work presents the state-of-art of filtration in ultrasonic field, in order to contribute to the development of a new treatment technology applicable to the produced water problem. (author)

  20. Dynamics of intrarenal pressures and glomerular filtration rate after acetazolamide

    DEFF Research Database (Denmark)

    Leyssac, P P; Karlsen, F M; Skøtt, O

    1991-01-01

    The dynamics of intrarenal pressures, early distal tubular fluid conductivity (EDC), and renal flood flow (RBF) were studied in rats given acetazolamide (ACZ), an inhibitor of proximal reabsorption. Glomerular filtration rate (GFR) and end-proximal flow were estimated by clearances of 51Cr......-EDTA and lithium. Proximal tubular pressure (Pprox) increased initially by 1.7 +/- 0.1 mmHg after ACZ, causing a decrease in the hydrostatic pressure difference across the glomerular membrane (delta P). EDC increased, and then RBF, glomerular capillary pressure (Pgc), Pprox, and star vessel pressures (Psv) dropped...

  1. Particulate filtration for sorbent-based H2 storage

    Science.gov (United States)

    van Hassel, Bart A.; Karra, Jagadeswara R.

    2016-01-01

    A method was developed for sizing the particulate filter that can be used inside a sorption-based onboard hydrogen storage system for light-duty vehicles. The method is based on a trade-off between the pressure drop across the particulate filter (during the fill of the H2 storage tank or during its discharge while driving) and the effect of this pressure drop on the usable amount of H2 gas from the H2 storage system. The permeability and filtration efficiency of the particulate filters (in the absence and presence of MOF-5 particulates) was quantified in this study, with an emphasis on meeting DOE's H2 purity requirements.

  2. Improved Filtration Technology for Pathogen Reduction in Rural Water Supplies

    Directory of Open Access Journals (Sweden)

    Valentine Tellen

    2010-06-01

    Full Text Available Intermittent bio-sand filtration (BSF is a low-cost process for improving water quality in rural households. This study addresses its two drawbacks: flow limitations requiring excessive waiting, and inadequate purification when high flows are imposed. Two modifications were examined: increasing the sand’s effective size, and adding zero-valent iron (ZVI into the media as a disinfectant. After 65 days, percent reductions in total coliform, fecal coliform, and fecal streptococci averaged 98.9% for traditional BSF and 99% for the improved BSF. Both modifications showed statistically significant improvements. Increased sand size and ZVI addition can counter the drawbacks of traditional BSF.

  3. Microalgae fractionation using steam explosion, dynamic and tangential cross-flow membrane filtration.

    Science.gov (United States)

    Lorente, E; Hapońska, M; Clavero, E; Torras, C; Salvadó, J

    2017-08-01

    In this study, the microalga Nannochloropsis gaditana was subjected to acid catalysed steam explosion treatment and the resulting exploded material was subsequently fractionated to separate the different fractions (lipids, sugars and solids). Conventional and vibrational membrane setups were used with several polymeric commercial membranes. Two different routes were followed: 1) filtration+lipid solvent extraction and 2) lipid solvent extraction+filtration. Route 1 revealed to be much better since the used membrane for filtration was able to permeate the sugar aqueous phase and retained the fraction containing lipids; after this, an extraction required a much lower amount of solvent and a better recovering yield. Filtration allowed complete lipid rejection. Dynamic filtration improved permeability compared to the tangential cross-flow filtration. Best membrane performance was achieved using a 5000Da membrane with the dynamic system, obtaining a permeability of 6L/h/m 2 /bar. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Synthesis of soft shell poly(styrene) colloids for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens

    these structures influence the filtration dewatering characteristic of organic materials. One of the structures that have been identified to affect the filtration dewatering behavior of activated sludge is the amount of extracellular polymer substance (EPS). EPS is a water swollen material and it has been shown...... that the more EPS the larger resistance to filtration. It is difficult to access the influence of water swollen material (as EPS) on the filtration dewatering of activated sludge by performing filtration dewatering experiments on activated sludge. A reason for this is that activated sludge is a physical...... and chemical complex material that is biological active. It is therefore difficult to extract the effect from one single material parameter as the effect from the amount or type of water swollen material from filtration dewatering experiments performed on activated sludge. Substituting the complex organic...

  5. Towards a Modern Theory of Multiphase Filtration Flow

    Science.gov (United States)

    Buyevich, Yu A.; Webbon, Bruce W. (Technical Monitor)

    1994-01-01

    An alternative theoretical model of joint filtration flow of immiscible incompressible fluids is presented. The model takes into account relaxation processes due to the interchange of the fluids between pores of difference sizes which is driven by capillary forces. The fluids occupy connected regions in a four-dimensional space formed by three coordinates and the pore length scale. When the fluid exchange between pores of given sizes is effected by way of successive flow through pores of all the intermediate sizes, the pressure within each region is governed by a hyperbolic equation, the role of time being played by the pore linear scale. Pressure jumps across hypersurfaces separating the regions equal corresponding values of the capillary pressure. A supplementary condition at any such hypersurface requires the speed of its displacement in the four-dimensional space to coincide with the normal velocity components of both the adjoining fluids. As a result, a principally new statement of multiphase filtration flow problems is gained with allowance for capillary relaxation in the porous space.

  6. Dedicated breast CT: effect of adaptive filtration on dose distribution

    CERN Document Server

    Shikhaliev, Polad M

    2016-01-01

    Purpose: The purpose of the work was experimental investigations of the breast dose distributions with adaptive filtration. Adaptive filtration reduces detector dynamic range and improves image quality. The adaptive filter with predetermined shape is placed at the x-ray beam such that the x-ray intensity at the detector surface is flat. However, adaptive filter alters the mean dose to the breast, as well as volume distribution of the dose. Methods: The dose was measured using a 14 cm diameter cylindrical acrylic breast phantom. An acrylic adaptive filter was fabricated to match the 14 cm diameter of the phantom. The dose was measured using ion chamber inserted into holes distributed along the radius of the phantom from the center to the edge. The radial distribution of dose was measured and fitted by an analytical function and the volume distribution and mean value of dose was calculated. The measurements were performed at 40, 60, 90, and 120 kVp tube voltages and 6.6 mGy air kerma. Results: The adaptive filt...

  7. Filtrations on Springer fiber cohomology and Kostka polynomials

    Science.gov (United States)

    Bellamy, Gwyn; Schedler, Travis

    2017-09-01

    We prove a conjecture which expresses the bigraded Poisson-de Rham homology of the nilpotent cone of a semisimple Lie algebra in terms of the generalized (one-variable) Kostka polynomials, via a formula suggested by Lusztig. This allows us to construct a canonical family of filtrations on the flag variety cohomology, and hence on irreducible representations of the Weyl group, whose Hilbert series are given by the generalized Kostka polynomials. We deduce consequences for the cohomology of all Springer fibers. In particular, this computes the grading on the zeroth Poisson homology of all classical finite W-algebras, as well as the filtration on the zeroth Hochschild homology of all quantum finite W-algebras, and we generalize to all homology degrees. As a consequence, we deduce a conjecture of Proudfoot on symplectic duality, relating in type A the Poisson homology of Slodowy slices to the intersection cohomology of nilpotent orbit closures. In the last section, we give an analogue of our main theorem in the setting of mirabolic D-modules.

  8. The PBW Filtration, Demazure Modules and Toroidal Current Algebras

    Directory of Open Access Journals (Sweden)

    Evgeny Feigin

    2008-10-01

    Full Text Available Let L be the basic (level one vacuum representation of the affine Kac-Moody Lie algebra ^g. The m-th space F_m of the PBW filtration on L is a linear span of vectors of the form x_1dots x_lv_0, where l ≤ m, x_i in ^g and v_0 is a highest weight vector of L. In this paper we give two descriptions of the associated graded space L^{gr} with respect to the PBW filtration. The ''top-down'' description deals with a structure of L^{gr} as a representation of the abelianized algebra of generating operators. We prove that the ideal of relations is generated by the coefficients of the squared field e_θ(z2, which corresponds to the longest root θ. The ''bottom-up'' description deals with the structure of L^{gr} as a representation of the current algebra g otimes C[t]. We prove that each quotient F_m/F_{m-1} can be filtered by graded deformations of the tensor products of m copies of g.

  9. Membrane filtration and sonication for industrial wastewater reuse.

    Science.gov (United States)

    Caretti, C; Coppini, E; Fatarella, E; Lubello, C

    2011-01-01

    This paper presents an experimental study aimed at estimating the efficiency of the innovative process of ultrafiltration (UF) combined with sonication (Son.) for the refinement of treated effluent to be reused in wet textile processes. Such a novel approach, which has not yet been employed on a full industrial scale, has been experienced at pilot scale on the secondary effluent of the Baciacavallo wastewater treatment plant (WWTP), which treats part of the effluent from one of the largest textile industry districts in Italy. The combined treatment efficiency was assessed both on ozonated and non-ozonated Baciacavallo secondary effluent. The membrane filtration process was optimized in terms of running time, backwash, chemical addition and cleaning procedures. The sonication treatment was optimized on laboratory-scale with synthetic solutions (demineralized water added with dyestuffs) in terms of hydroxyl radicals formation rate, frequency, acoustic power, hydrogen peroxide addition, contact time and pH. The optimal conditions have been applied on the pilot-scale sonicator which was used in combination with the UF treatment. According to the experimental results, the best configuration within the Baciacavallo WWTP was the sonication of non-ozonated wastewater followed by the UF. The combined treatment guaranteed the compliance with the target values for wastewater reuse in wet textile industries. This study is part of the Research Project PURIFAST (Purification of industrial and mixed wastewater by combined membrane filtration and sonochemical technologies) LIFE + ENV/IT/000439.

  10. Efficacy of arsenic filtration by Kanchan arsenic filter in Nepal.

    Science.gov (United States)

    Singh, Anjana; Smith, Linda S; Shrestha, Shreekrishna; Maden, Narendra

    2014-09-01

    Groundwater arsenic contamination has caused a significant public health burden in lowland regions of Nepal. For arsenic mitigation purposes, the Kanchan Arsenic Filter (KAF) was developed and validated for use in 2003 after pilot studies showed its effectiveness in removing arsenic. However, its efficacy in field conditions operating for a long period has been scarcely observed. In this study, we observe the efficacy of KAFs running over 6 months in highly arsenic-affected households in Nawalparasi district. We assessed pair-wise arsenic concentrations of 62 randomly selected household tubewells before filtration and after filtration via KAFs. Of 62 tubewells, 41 had influent arsenic concentration exceeding the Nepal drinking water quality standard value (50 μg/L). Of the 41 tubewells having unsafe arsenic levels, KAFs reduced arsenic concentration to the safe level for only 22 tubewells, an efficacy of 54%. In conclusion, we did not find significantly high efficacy of KAFs in reducing unsafe influent arsenic level to the safe level under the in situ field conditions.

  11. Asymptotics of the filtration problem for suspension in porous media

    Directory of Open Access Journals (Sweden)

    Kuzmina Ludmila Ivanovna

    2015-01-01

    Full Text Available The mechanical-geometric model of the suspension filtering in the porous media is considered. Suspended solid particles of the same size move with suspension flow through the porous media - a solid body with pores - channels of constant cross section. It is assumed that the particles pass freely through the pores of large diameter and are stuck at the inlet of pores that are smaller than the particle size. It is considered that one particle can clog only one small pore and vice versa. The particles stuck in the pores remain motionless and form a deposit. The concentrations of suspended and retained particles satisfy a quasilinear hyperbolic system of partial differential equations of the first order, obtained as a result of macro-averaging of micro-stochastic diffusion equations. Initially the porous media contains no particles and both concentrations are equal to zero; the suspension supplied to the porous media inlet has a constant concentration of suspended particles. The flow of particles moves in the porous media with a constant speed, before the wave front the concentrations of suspended and retained particles are zero. Assuming that the filtration coefficient is small we construct an asymptotic solution of the filtration problem over the concentration front. The terms of the asymptotic expansions satisfy linear partial differential equations of the first order and are determined successively in an explicit form. It is shown that in the simplest case the asymptotics found matches the known asymptotic expansion of the solution near the concentration front.

  12. Turbidity removal: Gravel and charcoal as roughing filtration media

    Directory of Open Access Journals (Sweden)

    Josiah A. Adeyemo

    2010-10-01

    Full Text Available Roughing filtration is an important pre-treatment process for wastewater, because it efficiently separates fine solid particles over prolonged periods, without the addition of chemicals. For this study, a pilot plant was designed at Delmas Coal Mine in the Mpumalanga province of South Africa. The design and sizing of the pilot plant was guided by Wegelin’s design criteria. Gravel was used as a control medium because it is one of the most commonly used roughing filter media and because it was used in developing the criteria. We compared the performance of gravel as a filter medium to that of another locally available material, charcoal, for the removal of turbidity in wastewater. The pilot plant was monitored continuously for 90 days from commissioning until the end of the project. The overall performance of the roughing filter in turbidity removal, using gravel or charcoal, was considered efficient for the pre-treatment of waste water. Charcoal performed slightly better than gravel as a filter medium for the removal of turbidity, possibly because charcoal has a slightly higher specific surface area and porosity than gravel, which could enhance sedimentation and other filtration processes, such as adsorption, respectively.

  13. Optimum filtration for time-activity curves in nuclear medicine.

    Science.gov (United States)

    Rajabi, H; Pant, G S

    2000-09-01

    Insufficient filtration and over-smoothing are misleading processes in the quantification of time-activity curves. The optimum filtration requires a good knowledge of the frequency spectrum and relative amplitudes of the data and superimposed noise. Due to variations in biomedical data, it is very difficult to adjust the filter for individual cases. To overcome this problem a new method of noise reduction is proposed. In this method the time-activity curves are transformed into a low frequency (linear) curve that can be filtered heavily without significant distortion of the real data. The theory of the proposed filter and the results of its comparison with three-point filter, five-point filter and data bounding methods are presented. The comparison was performed using deconvolution analyses of simulated renograms. The results show that the proposed filter causes minimum distortion of the renogram and impulse retention function in terms of the root mean square error and the peak of the renogram. Moreover, the filter is much less sensitive to over-smoothing (number of filter iterations), the signal-to-noise ratio and the mean transit time of the renogram compared with other filters.

  14. Performance of an anaerobic membrane bioreactor in which granular sludge and dynamic filtration are integrated.

    Science.gov (United States)

    Yang, Jixiang; Ji, Xin; Lu, Lunhui; Ma, Hua; Chen, Youpeng; Guo, Jinsong; Fang, Fang

    2017-01-01

    To alleviate the fouling of a filter, simple substrates, dynamic filtration, and granular sludge were applied in an anaerobic membrane bioreactor (AnMBR). The results showed that under a transmembrane pressure filtration layer formed on the filter, which contributed to low effluent chemical oxygen demand concentrations and turbidity. In addition, substrate scarcity in the filtration zone resulted in the evolution of diverse bacteria on the filter.

  15. The direct filtration in a conventional water treatment plant; La filtracion directa en una ETAP convencional

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Quiros, F. [Canal de Isabel II, Madrid (Spain)

    1995-06-01

    The article describes the difficulty of the decantation of low turbidity water. Direct filtration and in-line filtration can be available alternative treatment process to coagulation, flocculation, with the minimum required chemical dosage especially coagulants, less sludge production and lower operation cost. The adaptation of conventional treatment plant to direct filtration system with recuperation of filters backwash water by eliminating the decantation, is relatively simple. The result to apply this process shows an efficient filters performance for the same effluent quality. (Author)

  16. The influence of organic acid concentration in methanogenic waste on membrane filtration characteristics.

    OpenAIRE

    清水, 康利; 六代, 稔; 遠矢, 幸男; 栢分, 英助; 矢沢, 哲夫; 田中, 博史; 江口, 清久; YASUTOSHI, SHIMIZU; MINORU, ROKUDAI; SACHIO, TOHYA; EISUKE, KAYAWAKE; TETSUO, YAZAWA; Hiroshi, Tanaka; KIYOHISA, EGUCHI; 東陶機器(株)研究所水処理研究室

    1989-01-01

    For the purpose of developing a methane fermentation membrane bioreactor for wastewater treatment, the influence of operations concerning the fermentor on the filtration characteristics was examined. The fermentation broth, which was produced by an ill-poerated reactor ot concentrate the organic acid in the broth and which was neutralized by NaOH, was used for filtration tests. And also, the fermentation broth from the stably methane fermented reactor was used for filtration tests to compare ...

  17. Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

    Science.gov (United States)

    Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

    2015-10-01

    Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  18. Reverse osmosis followed by activated carbon filtration for efficient removal of organic micropollutants from river bank filtrate.

    Science.gov (United States)

    Kegel, F Schoonenberg; Rietman, B M; Verliefde, A R D

    2010-01-01

    Drinking water utilities in Europe are faced with a growing presence of organic micropollutants in their water sources. The aim of this research was to assess the robustness of a drinking water treatment plant equipped with reverse osmosis and subsequent activated carbon filtration for the removal of these pollutants. The total removal efficiency of 47 organic micropollutants was investigated. Results indicated that removal of most organic micropollutants was high for all membranes tested. Some selected micropollutants were less efficiently removed (e.g. the small and polar NDMA and glyphosate, and the more hydrophobic ethylbenzene and napthalene). Very high removal efficiencies for almost all organic micropollutants by the subsequent activated carbon, fed with the permeate stream of the RO element were observed except for the very small and polar NDMA and 1,4-dioxane. RO and subsequent activated carbon filtration are complementary and their combined application results in the removal of a large part of these emerging organic micropollutants. Based on these experiments it can be concluded that the robustness of a proposed treatment scheme for the drinking water treatment plant Engelse Werk is sufficiently guaranteed.

  19. Antimicrobial filtration with electrospun poly(vinyl alcohol) nanofibers containing benzyl triethylammonium chloride: Immersion, leaching, toxicity, and filtration tests.

    Science.gov (United States)

    Park, Jeong-Ann; Kim, Song-Bae

    2017-01-01

    Antimicrobial electrospun poly(vinyl alcohol) (PVA) nanofibers were synthesized by impregnating benzyl triethylammonium chloride (BTEAC) as an antimicrobial agent into PVA nanofibers. The BTEAC-PVA nanofibers were heat-methanol treated during the preparation for various tests. The BTEAC-PVA nanofibers became more hydrophilic than the PVA nanofibers due to incorporation of BTEAC. Through heat-methanol treatment, thermal property, crystallinity, and water stability of BTEAC-PVA nanofibers were improved considerably. The immersion test shows that heat-methanol treatment has an advantage over heat treatment to maintain BTEAC content in BTEAC-PVA nanofibers. The acute toxicity test demonstrates that the 24-h EC50 and 48-h EC50 values (EC50 = median effective concentration) of BTEAC to Daphnia magna were 113 and 90 mg/L, respectively. The leaching test indicates that the BTEAC concentration leached from BTEAC-PVA nanofibers was far below the concentration affecting the immobilization of D. magna. For antimicrobial filtration tests, the BTEAC-PVA nanofibers were deposited onto glass fiber filter. The antimicrobial filtration test was conducted against bacteria (Escherichia coli, Staphylococcus aureus) and bacteriophages (MS2, PhiX174), demonstrating that the BTEAC-PVA nanofibers could enhance the removal of E. coli and S. aureus considerably but not the removal of MS2 and PhiX174 under dynamic flow conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Is the use of particle air filtration justified? Costs and benefits of filtration with regard to health effects, building cleaning and occupant productivity

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    is impacted by maintenance of the building and its HVAC system; society is impacted by the employees’ health and welfare. Regardless of perspective, particle filtration is anticipated to lead to annual savings significantly exceeding the running costs for filtration. However, economic losses resulting from......Estimates of costs and the corresponding benefits of particle filtration have been derived for a standard office building. Reduction in occupants’ exposure to particles during their workday is anticipated to reduce their morbidity and mortality. Filtration may also reduce the costs associated...... with building and HVAC cleaning. Conversely, losses of occupant productivity due to sensory offending pollutants emitted from used ventilation filters can lead to significant economic losses. The results of the present analysis are strongly dependent on several key input parameters; consequently...

  1. Advanced Emissions Control Development Program: Phase III

    Energy Technology Data Exchange (ETDEWEB)

    G.T. Amrhein; R.T. Bailey; W. Downs; M.J. Holmes; G.A. Kudlac; D.A. Madden

    1999-07-01

    The primary objective of the Advanced Emissions Control Development Program (AECDP) is to develop practical, cost-effective strategies for reducing the emissions of air toxics from coal-fired boilers. The project goal is to effectively control air toxic emissions through the use of conventional flue gas clean-up equipment such as electrostatic precipitators (ESPs), fabric filters (baghouses - BH), and wet flue gas desulfurization systems (WFGD). Development work concentrated on the capture of trace metals, fine particulate, hydrogen chloride and hydrogen fluoride, with an emphasis on the control of mercury. The AECDP project is jointly funded by the US Department of Energy's Federal Energy Technology Center (DOE), the Ohio Coal Development Office within the Ohio Department of Development (OCDO), and Babcock and Wilcox, a McDermott company (B and W). This report discusses results of all three phases of the AECDP project with an emphasis on Phase III activities. Following the construction and evaluation of a representative air toxics test facility in Phase I, Phase II focused on characterization of the emissions of mercury and other air toxics and the control of these emissions for typical operating conditions of conventional flue gas clean-up equipment. Some general comments that can be made about the control of air toxics while burning a high-sulfur bituminous coal are as follows: (1) particulate control devices such as ESP's and baghouses do a good job of removing non-volatile trace metals, (2) particulate control devices (ESPs and baghouses) effectively remove the particulate-phase mercury, but the particulate-phase mercury was only a small fraction of the total for the coals tested, (3) wet scrubbing can effectively remove hydrogen chloride and hydrogen fluoride, and (4) wet scrubbers show good potential for the removal of mercury when operated under certain conditions, however, for certain applications, system enhancements can be required to achieve

  2. Electrokinetic focusing and filtration of cells in a serpentine microchannel

    Science.gov (United States)

    Church, Christopher; Zhu, Junjie; Wang, Gaoyan; Tzeng, Tzuen-Rong J.; Xuan, Xiangchun

    2009-01-01

    Focusing cells into a single stream is usually a necessary step prior to counting and separating them in microfluidic devices such as flow cytometers and cell sorters. This work presents a sheathless electrokinetic focusing of yeast cells in a planar serpentine microchannel using dc-biased ac electric fields. The concurrent pumping and focusing of yeast cells arise from the dc electrokinetic transport and the turn-induced ac∕dc dielectrophoretic motion, respectively. The effects of electric field (including ac to dc field ratio and ac field frequency) and concentration (including buffer concentration and cell concentration) on the cell focusing performance were studied experimentally and numerically. A continuous electrokinetic filtration of E. coli cells from yeast cells was also demonstrated via their differential electrokinetic focusing in a serpentine microchannel. PMID:20216971

  3. Hot-gas filtration for pressurized fluidized-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Chang, R.; Kuby, W.

    1984-03-01

    This topical report discusses the status of the work, conducted under EPRI contract 1336-4, on the evaluation and development of ceramic filter hot gas cleanup technology for pressurized fluidized bed combustion. This topical report represents the status of the work through September 1983. The goal of the effort is to achieve 6000 h of operation on a 13-filter durability test rig. The work includes two parallel tasks. The first is construction of a durability test facility, operation of the facility with an initial candidate filter media installed, and assessment of results. The second task includes a literature survey to identify state-of-the-art ceramic fibers suitable for high-temperature gas filtration applications and filter testing in a single-filter test facility to assess the performance of promising new filter media. The best candidate will be chosen for further evaluation in the durability facility.

  4. Filtration of Glass Delamination Particles with West Pharmaceutical Vial Adapters.

    Science.gov (United States)

    Zarour-Shalev, Elinor H; Ovadia, Yaron; Tuchmay, Oren; Reynolds, Graham; Lev, Nimrod

    2015-01-01

    One major current challenge facing companies producing injectable drugs contained in glass vials is the phenomenon of delamination that results in drug contamination. Particulate contamination of parenteral fluids is a fact of life. Particulate infusion is unlikely to cause immediate or severe signs and symptoms, but adverse effects, tissue damage, and loss of function are likely in the long term. Since 2010, recalls due to glass delamination have increased, and recently the U.S. Food and Drug Administration exercised temporary regulatory flexibility by allowing filtration as means of removing glass particles. The vial adapter is a needle-free product from West Pharmaceuticals Services that provides a simple and cost-effective solution for the safe and rapid transfer reconstitution of drugs between vials and syringes. One variant of the vial adapter is integrated with a filter to address various types of particles. In the present study, the performance of the filter-integrated vial adapter is evaluated with respect to glass delamination particles. Silica particles of 0.5-10 μm are used to emulate glass delamination particles. High-filtration efficiency is demonstrated according to the severest criteria stated by the British Pharmacopoeia that allows up to 100 particles smaller than 5 μm for every 1 mL liquid of a large-volume parenteral. The study was conducted using environmental scanning electron microscopy and statistical analysis. One major current challenge facing companies producing injectable drugs contained in glass vials is the phenomenon of delamination that results in drug contamination. Glass delamination is defined as degradation of surface glass, as from a vial, that produces glass flakes. Contamination of injectable drugs due to glass delamination is a fact of life. Normally, this type of contamination does not involve immediate severe signs, but rather accumulative damage to tissues in the long run. Recently, the U.S. Food and Drug Administration

  5. Glomerular filtration rate in cows estimated by a prediction formula.

    Science.gov (United States)

    Murayama, Isao; Miyano, Anna; Sato, Tsubasa; Iwama, Ryosuke; Satoh, Hiroshi; Ichijyo, Toshihiro; Sato, Shigeru; Furuhama, Kazuhisa

    2014-12-01

    To testify the relevance of Jacobsson's equation for estimating bovine glomerular filtration rate (GFR), we prepared an integrated formula based on its equation using clinically healthy dairy (n=99) and beef (n=63) cows, and cows with reduced renal function (n=15). The isotonic, nonionic, contrast medium iodixanol was utilized as a test tracer. The GFR values estimated from the integrated formula were well consistent with those from the standard multisample method in each cow strain, and the Holstein equation prepared by a single blood sample in Holstein dairy cows. The basal reference GFR value in healthy dairy cows was significantly higher than that in healthy beef cows, presumably due to a breed difference or physiological state difference. It is concluded that the validity for the application of Jacobsson's equation to estimate bovine GFR is proven and it can be used in bovine practices. © 2014 Japanese Society of Animal Science.

  6. Organic-inorganic membranes for filtration of corn distillery

    Directory of Open Access Journals (Sweden)

    Myronchuk Valeriy G.

    2016-01-01

    Full Text Available Organic-inorganic membranes were obtained by modification of polymer microfiltration membrane with inorganic ion-exchangers, which form secondary porosity inside macroporous substrate (zirconium hydrophosphate or simultaneously in the macroporous substrate and active layer, depending of the particle size (from ≈50 nm up to several microns. Precipitation of the inorganic constituent is considered from the point of view of Ostwald-Freundlich equation. Such processes as pressing test in deionized water and filtration of corn distillery at 1-6 bar were investigated. Theoretical model allowing to establish fouling mechanism, was applied. It was found that the particles both in the substrate and active layer prevent fouling of the membrane with organics and provide rejection of colloidal particles.

  7. Allelopathic Effects of Cyanobacterial Filtrates on Baltic Diatom

    Science.gov (United States)

    Śliwińska, Sylwia; Latała, Adam

    2012-01-01

    Allelopathy may be one of the factors affecting the formation of massive and harmful algal blooms in aquatic environments. Recent studies indicate that blooms of cyanobacteria in the Baltic Sea has grown significantly in last decades, so it is important to determine the allelopathic interactions between the dominant species of cyanobacteria and microalgae. In this work we investigated the influence of allelopathic compounds on the growth of Skeletonema marinoi by addition of cell-free filtrate of the Baltic cyanobacterium Nodularia spumigena cultures grown under different temperature (15-25°C). Additionally the effects of filtrates of both an exponential and a stationary growing culture of N. spumigena were tested on diatom. These studies indicate that high temperature affected the donor species by increasing its production of allelochemicals. The highest drop of growth of analyzed diatom were observed after the addition of cell-free filtrate obtained from N. spumigena grown at 25°C and constituted 70% of their control. N. spumigena was only allelopathic in exponential growth phase, whereas the cyanobacteria filtrate from stationary phase have any effect on S. marinoi. These findings suggest that N. spumigena may reveal allelopathic activity and that the production of allelopathic substances is influenced by the temperature and growth phase of cyanobacteria. Allelopatia może być kluczowym czynnikiem wpływającym na tworzenie się masowych zakwitów sinic w wielu wodnych ekosystemach. Badania pokazują, że zakwity sinic w Morzu Bałtyckim w ostatnich dekadach znacznie się nasiliły, dlatego tak ważne jest określenie stopnia oddziaływania allelopatycznego dominujących w tym akwenie gatunków fitoplanktonu. W przeprowadzonych badaniach określono wpływ związków allelopatycznych produkowanych przez bałtycką sinicę Nodularia spumigena hodowaną w różnych temperaturach (15-25°C) na wzrost okrzemki Skeletonema marinoi. Dodatkowo w niniejszej pracy por

  8. The Use of Coupled Plasma Filtration Adsorption in Traumatic Rhabdomyolysis.

    Science.gov (United States)

    Pezzi, Mario; Renda, Silvia; Giglio, Anna Maria; Scozzafava, Anna Maria; Tiburzi, Simona Paola; Casella, Patrizia; Iannelli, Fabrizio; Verre, Mario

    2017-01-01

    Severe musculoskeletal injuries induce the release of sarcoplasmic elements such as muscle enzymes, potassium, and myoglobin in the systemic circulation. The circulating myoglobin damages the glomerulus and renal tubules. Conventional haemodialysis is not able to remove myoglobin, due to its high molecular weight (17,8 kilodaltons [kDa]). We treated four traumatic rhabdomyolysis patients with Coupled Plasma Filtration Adsorption (CPFA) in order to remove myoglobin followed by 14 hours of Continuous Veno-Venous Hemofiltration (CVVH). During the treatment, all patients showed clinical improvement with a decrease in muscular (creatine kinase [CK] and myoglobin) and renal (creatinine and potassium) damage indices. One patient, in spite of full renal recovery, died of cerebral haemorrhage on the 26th day of hospital stay.

  9. The Use of Coupled Plasma Filtration Adsorption in Traumatic Rhabdomyolysis

    Directory of Open Access Journals (Sweden)

    Mario Pezzi

    2017-01-01

    Full Text Available Severe musculoskeletal injuries induce the release of sarcoplasmic elements such as muscle enzymes, potassium, and myoglobin in the systemic circulation. The circulating myoglobin damages the glomerulus and renal tubules. Conventional haemodialysis is not able to remove myoglobin, due to its high molecular weight (17,8 kilodaltons [kDa]. We treated four traumatic rhabdomyolysis patients with Coupled Plasma Filtration Adsorption (CPFA in order to remove myoglobin followed by 14 hours of Continuous Veno-Venous Hemofiltration (CVVH. During the treatment, all patients showed clinical improvement with a decrease in muscular (creatine kinase [CK] and myoglobin and renal (creatinine and potassium damage indices. One patient, in spite of full renal recovery, died of cerebral haemorrhage on the 26th day of hospital stay.

  10. Mechanistic evaluation of virus clearance by depth filtration.

    Science.gov (United States)

    Venkiteshwaran, Adith; Fogle, Jace; Patnaik, Purbasa; Kowle, Ron; Chen, Dayue

    2015-01-01

    Virus clearance by depth filtration has not been well-understood mechanistically due to lack of quantitative data on filter charge characteristics and absence of systematic studies. It is generally believed that both electrostatic interactions and sized based mechanical entrapment contribute to virus clearance by depth filtration. In order to establish whether the effectiveness of virus clearance correlates with the charge characteristics of a given depth filter, a counter-ion displacement technique was employed to determine the ionic capacity for several depth filters. Two depth filters (Millipore B1HC and X0HC) with significant differences in ionic capacities were selected and evaluated for their ability to eliminate viruses. The high ionic capacity X0HC filter showed complete porcine parvovirus (PPV) clearance (eliminating the spiked viruses to below the limit of detection) under low conductivity conditions (≤2.5 mS/cm), achieving a log10 reduction factor (LRF) of > 4.8. On the other hand, the low ionic capacity B1HC filter achieved only ∼2.1-3.0 LRF of PPV clearance under the same conditions. These results indicate that parvovirus clearance by these two depth filters are mainly achieved via electrostatic interactions between the filters and PPV. When much larger xenotropic murine leukemia virus (XMuLV) was used as the model virus, complete retrovirus clearance was obtained under all conditions evaluated for both depth filters, suggesting the involvement of mechanisms other than just electrostatic interactions in XMuLV clearance. © 2014 American Institute of Chemical Engineers.

  11. Behavior of Gd-DTPA in simulated bank filtration

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Peter, E-mail: pemoe@gfz-potsdam.de [Freie Universitaet Berlin, Malteserstr. 74-100, AB Hydrogeologie, 12249 Berlin (Germany)] [Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg, 14473 Potsdam (Germany); Knappe, Andrea [Freie Universitaet Berlin, Malteserstr. 74-100, AB Hydrogeologie, 12249 Berlin (Germany); Dulski, Peter [Helmholtz Zentrum Potsdam, Deutsches GeoForschungsZentrum, Telegrafenberg, 14473 Potsdam (Germany); Pekdeger, Asaf [Freie Universitaet Berlin, Malteserstr. 74-100, AB Hydrogeologie, 12249 Berlin (Germany)

    2011-01-15

    Research highlights: {yields} Gd-DTPA and similar products are common pollutants in surface and groundwater and prove to be a reliable monitor for mixing of groundwater with surface water loaded with effluents from sewage treatment plants. {yields} Within a 30 m column filled with Pleistocene sand Gd-DTPA is reduced by 16% only within one month time by transmetallation. {yields} Artificial bank filtration is not very effective in reducing Gd-DTPA in infiltrating water. - Abstract: The behavior of Gd-DTPA during bank filtration was simulated in a 30 m column filled with Pleistocene sand and flushed by surface water from a lakeside in Berlin, Germany. The surface water is about a 1:1 mixture of river water and effluents from a sewage treatment plant. Throughout 34 days this water was continuously spiked with Gd-DTPA at a level of 60 {mu}g/L. The broad plateau of the Gd-DTPA pulse declined by 15.4% within 34 days by transmetallation. Nine percentage of the total decline is caused by Y and rare earth elements; the remaining part is attributed to Cu{sup 2+} which is the most influential metal in surface water. All other metals also contributing to transmetallation are combined with Cu to Cu equivalents because only the rate constant of transmetallation of Cu{sup 2+} is known. The analytical results of the column effluents prove the pseudo-first-order kinetics of transmetallation based on reversible sorption of metals by pools in the column sediment and disprove biodegradation at noticeable levels. The mass ratio of water to tracer is <10{sup 10}.

  12. Filtration-guided assembly for patterning one-dimensional nanostructures

    Science.gov (United States)

    Zhang, Yaozhong; Wang, Chuan; Yeom, Junghoon

    2017-04-01

    Tremendous progress has been made in synthesizing various types of one-dimensional (1D) nanostructures (NSs), such as nanotubes and nanowires, but some technical challenges still remain in the deterministic assembly of the solution-processed 1D NSs for device integration. In this work we investigate a scalable yet inexpensive nanomaterial assembly method, namely filtration-guided assembly (FGA), to place nanomaterials into desired locations as either an individual entity or ensembles, and form functional devices. FGA not only addresses the assembly challenges but also encompasses the notion of green nanomanufacturing, maximally utilizing nanomaterials and eliminating a waste stream of nanomaterials into the environment. FGA utilizes selective filtration of 1D NSs through the open windows on the nanoporous filter membrane whose surface is patterned by a polymer mask for guiding the 1D NS deposition. The modified soft-lithographic technique called blanket transfer (BT) is employed to create the various photoresist patterns of sub-10-micron resolution on the nanoporous filter membrane like mixed cellulose acetate. We use single-walled carbon nanotubes (SWCNTs) as a model 1D NS and demonstrate the fabrication of an array pattern of homogeneous 1D NS network films over an area of 20 cm2 within 10 min. The FGA-patterned SWCNT network films are transferred onto the substrate using the adhesive-based transfer technique, and show the highly uniform film thickness and resistance measurements across the entire substrate. Finally, the electrical performance of the back-gated transistors made from the FGA and transfer method of 95% pure SWCNTs is demonstrated.

  13. MULTILAYER POROUS COMPOSITE FROM WASTE GLASS FOR WATER FILTRATION

    Directory of Open Access Journals (Sweden)

    M. P. Aji

    2015-07-01

    Full Text Available Multilayer porous composite have been produced through the heating process at temperature T=700oC for 2.5 h. Single layered porous composite was made with a varied mass percentage of from PEG polymer  1% to 10%. Double-layered porous composite were made by the arrangement of porosity (4:3%, (4:2% and (3:2%, while the three-layers porous composite have an arrangement (4:3:2%. Performance of multilayer porous composite for water filtration with pollutants of methylene blue 100 ppm was estimated from the absorbance spectrum. Rejection of methylene blue pollutants from single layered porous composite increases when the fraction of PEG polymer tend to be smaller in the matrix. Meanwhile, the double layered porous composite has a degradation of methylene blue pollutants are better than one layer. Triple layered porous composite have good performance for the water filtration where all the pollutants of methylene blue be able to be filtered.   Komposit pori berlapis telah dihasilkan dengan proses pemanasan pada temperatur T=700oC selama 2.5 jam. Komposit pori satu lapis dibuat dengan variasi persen massa polimer PEG 1% hingga 10%. Komposit pori dua lapis dibuat dengan susunan porositas (4:3%, (4:2% dan (3:2%, sedangkan komposit pori tiga lapis memiliki susunan porositas (4:3:2%. Kinerja komposit pori berlapis untuk filter air dengan polutan methylene blue 100 ppm diestimasi dari spektrum absorbansi. Rejeksi polutan methylene blue dari komposit pori satu lapis meningkat saat fraksi polimer PEG cenderung lebih kecil dalam matrik komposit. Sedangkan, komposit pori dua lapis memiliki kemampuan untuk degradasi polutan methylene blue yang lebih baik dari satu lapis. Komposit pori tiga lapis memiliki kinerja yang baik untuk filter air dimana seluruh polutan methylene blue mampu disaring. 

  14. Biotrickling filtration of isopropanol under intermittent loading conditions.

    Science.gov (United States)

    San-Valero, Pau; Penya-Roja, Josep M; Sempere, Feliu; Gabaldón, Carmen

    2013-07-01

    This paper investigates the removal of isopropanol by gas-phase biotrickling filtration. Two plastic packing materials, one structured and one random, have been evaluated in terms of oxygen mass transfer and isopropanol removal efficiency. Oxygen mass transfer experiments were performed at gas velocities of 104 and 312 m h⁻¹ and liquid velocities between 3 and 33 m h⁻¹. Both materials showed similar mass transfer coefficients up to liquid velocities of 15 m h⁻¹. At greater liquid velocities, the structured packing exhibited greater oxygen mass transfer coefficients. Biotrickling filtration experiments were carried out at inlet loads (IL) from 20 to 65 g C m⁻³ h⁻¹ and empty bed residence times (EBRT) from 14 to 160 s. To simulate typical industrial emissions, intermittent isopropanol loading (16 h/day, 5 day/week) and intermittent spraying frequency (15 min/1.5 h) were applied. Maximum elimination capacity of 51 g C m⁻³ h⁻¹ has been obtained for the random packing (IL of 65 g C m⁻³ h⁻¹, EBRT of 50 s). The decrease in irrigation frequency to 15 min every 3 h caused a decrease in the outlet emissions from 86 to 59 mg C Nm⁻³ (inlet of 500 mg C Nm⁻³). The expansion of spraying to night and weekend periods promoted the degradation of the isopropanol accumulated in the water tank during the day, reaching effluent concentrations as low as 44 mg C Nm⁻³. After a 7-week starvation period, the performance was recovered in less than 10 days, proving the robustness of the process.

  15. Leukocyte filtration lesion impairs functional coagulation in banked whole blood.

    Science.gov (United States)

    Siletz, Anaar; Burruss, Sigrid; Gruber, Terry; Ziman, Alyssa; Marder, Victor; Cryer, Henry Magill

    2017-09-01

    Whole blood (WB) transfusion is a promising alternative to component therapy in hemostatic resuscitation. Use of banked WB requires filtration of white blood cells (leukoreduction) and an established shelf life during which WB retains coagulant capacities. The goal of this study was to define the time course of coagulation stability in leukoreduced compared to unfiltered WB under standard refrigeration conditions. Twelve WB units were donated by healthy volunteers after routine screening. Five units underwent standard leukocyte filtration and five did not. Two units were aliquoted into filtered and unfiltered samples, with platelets added to each sample on day 14. Units were stored at 4°C and sampled on days 0, 1, 2, 3, 4, 5, 6, 7, 10, 14, 21, 28, and 35 for immediate thromboelastography (TEG) analysis, and centrifuged and stored at -80°C for later calibrated automated thrombogram and coagulation factor assays. K-dependent factors and fibrinogen were low normal, decreased slightly over 35 days and were similar between unfiltered and filtered units. Labile factors were better preserved in filtered units, although unfiltered units did not show impaired coagulation over 35 days. Filtered blood had delayed clot initiation on days 0, 1, and 2 as measured by TEG R (p < 0.021); slower clot progression (TEG α-angle) on days 0, 1, 2, 3, 4, 5, and 6 (p < 0.023); weaker final clot (TEG MA) on all days (p < 0.0001). Thrombin generation was delayed on day 28 (p = 0.046) and decreased on days 10, 21, 28, and 35 (p < 0.034). Addition of platelets to filtered WB rescued TEG MA. Filtered WB had decreased functional clotting capacity and thrombin generation and may not be suitable for hemostatic resuscitation as the sole blood product. Therapeutic, level IV.

  16. Effectiveness of quality control methods for glomerular filtration rate calculation.

    Science.gov (United States)

    McMeekin, Helena; Wickham, Fred; Barnfield, Mark; Burniston, Maria

    2016-07-01

    In this work, we aimed to identify the types of errors encountered in glomerular filtration rate (GFR) measurement and test the effectiveness of all published quality control (QC) methods for detection of clinically significant errors. A total of 412 GFR tests were carried out on adults and children. The three-point slope-intercept glomerular filtration rate (SI-GFR) was compared with the nine-point 'area under curve' calculation as a gold standard to determine the error in SI-GFR. The Durbin-Watson test was used to characterize the nature of the errors. The sensitivity, specificity and positive predictive value (PPV) of QC methods for detecting clinically significant errors were calculated and receiver operating characteristic curves were constructed. The QC methods were also applied to a dataset of 100 four-point GFR tests from different institutions. Model failure is the dominant cause of clinically significant error in this dataset, with individual point measurement errors only giving rise to clinically significant errors in a small number of cases. No QC test had an acceptable combination of sensitivity, PPV and specificity. The correlation coefficient QC test had the largest area under the receiver operating characteristic curve (0.73). No other QC test had an area greater than 0.57. All the QC methods have poor sensitivity and PPV for detecting clinically significant errors and so cannot be relied on to ensure a robust measurement of GFR, underlining the need for careful working practices and a thorough system of measurement checks. We found no evidence for the value of multiple sampling with respect to QC; until such evidence is published, their clinical utility is unproven.

  17. Use of membranes for heavy metal cationic wastewater treatment: flotation and membrane filtration

    Energy Technology Data Exchange (ETDEWEB)

    Sudilovskiy, P.S.; Kagramanov, G.G.; Trushin, A.M.; Kolesnikov, V.A. [D.I. Mendeleyev University of Chemical Technology of Russia, Moscow (Russian Federation)

    2007-08-15

    A new water treatment process - membrane flotation - is presented. The hydrodynamics of air sparging with the use of microporous membranes was studied as well as the membrane flotation efficacy for cationic wastewater treatment. The performance of membrane filtration processes was evaluated. Ways of integration of flotation and membrane filtration in cationic wastewater treatment practice are discussed. (orig.)

  18. Filtration track membranes and their biomedical applications; Trekowe membrany filtracyjne oraz ich zastosowania biomedyczne

    Energy Technology Data Exchange (ETDEWEB)

    Buczkowski, M.; Wawszczak, D.; Starosta, W. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    The characteristics of track filtration membranes has been performed. The investigation of radiation resistance has been carried out for different types of polymer foil used as a membrane material. Biomedical applications of track filtration membranes have been presented and discussed. 10 refs, 10 figs.

  19. estimated glomerular filtration rate and risk of survival in acute stroke

    African Journals Online (AJOL)

    2014-03-03

    Mar 3, 2014 ... rate or glomerular filtration barrier and occurrence of stroke. Arch Neurol 2008; 65: 934-938. 2. Matsushita K,Mahmoodi BK, Woodward M,. Emberson JR, Jafar TH, Jee SH et al. Comparison of risk prediction using the CKD-EPI equation and the. MDRD study equation for estimated glomerular filtration rate.

  20. Polymer-treated woody biomass: a filtration medium for removing phosphate from water

    Science.gov (United States)

    Thomas L Eberhardt

    2006-01-01

    A two-stage treatment of refined aspen wood fiber with solutions of carboxymethyl cellulose (CMC) and ferrous chloride afforded a filtration medium that was effective in removing phosphate from test solutions. To assess the stability of the filtration medium, samples exposed to the test solutions were analyzed by FTIR spectroscopy. The resultant spectra indicated that...

  1. The Application of Homogenate and Filtrate from Baltic Seaweeds in Seedling Growth Tests

    Directory of Open Access Journals (Sweden)

    Izabela Michalak

    2017-02-01

    Full Text Available Algal filtrate and homogenate, obtained from Baltic seaweeds, were applied in seedling growth tests. Radish seeds were used in order to assess algal products phytotoxicity and their biostimulant effect on growth and nutrient uptake. Algal filtrate, at concentrations ranging from 5.0% to 100% was used for seed soaking and as a liquid biostimulant (soil and foliar application. Algal homogenate was developed for seed coating. Algal filtrate and homogenate were also enriched with Zn(II ions in order to examine the influence on metal ion complexation. The optimal doses of algal filtrate and homogenate, as well as soaking time were established. Multi-elemental analyses of the raw biomass, filtrate, homogenate, and radish were also performed using ICP-OES (Inductively Coupled Plasma—Optical Emission Spectrometry. The best results in terms of seedlings’ length and weight were obtained using clear filtrate at a concentration of 50% applied to the soil and for homogenate applied at a dose of 50 mg/g of seeds. Clear filtrate at a concentration of 50% used for seed soaking for one hour showed the best results. The applied algal products increased the content of elements in seedlings. Among the tested products, a concentration of 50% algal filtrate is recommended for future pot and field experiments.

  2. Filtration of Nanoparticles: Evolution of Cake Structure and Pressure-Drop

    DEFF Research Database (Denmark)

    Elmøe, Tobias Dokkedal; Tricoli, Antonio; Grunwaldt, Jan-Dierk

    2009-01-01

    with constant solid volume fraction began to form, accompanied with build-up of pressuredrop which was in excellent agreement with classic cake filtration theory. An expression for the solid volume fraction of the cake (fsd,c) was obtained as a sole function of Pe. In addition, the filtration efficiency became...

  3. Clinical use of estimated glomerular filtration rate for evaluation of kidney function

    DEFF Research Database (Denmark)

    Broberg, Bo; Lindhardt, Morten; Rossing, Peter

    2013-01-01

    Estimating glomerular filtration rate by the Modification of Diet in Renal Disease or Chronic Kidney Disease Epidemiology Collaboration formulas gives a reasonable estimate of kidney function for e.g. classification of chronic kidney disease. Additionally the estimated glomerular filtration rate...

  4. Tools for Schools: Filtration for Improved Air Quality. Technical Services Bulletin.

    Science.gov (United States)

    2001

    This product bulletin addresses air pollution control in educational facilities to enhance educational performance, provides air quality recommendations for schools, and examines the filtration needs of various school areas. The types of air particles typically present are highlighted, and the use of proper filtration to control gases and vapors…

  5. BIOCOMPATIBILITY OF LEUKOCYTE REMOVAL FILTERS DURING BEDSIDE LEUKOCYTE FILTRATION OF RED-CELL CONCENTRATES

    NARCIS (Netherlands)

    GU, YJ; OBSTER, R; DEHAAN, J; HUET, RCGG; VANOEVEREN, W

    1992-01-01

    The biocompatibility of leukocyte removal filters was evaluated in four different types of leukocyte filters made from different materials during bedside leukocyte filtration of red cell concentrates (RCC). Two units of banked RCC were filtrated through each leukocyte filter inserted into the

  6. Routine filtration of hematopoietic stem cell products: the time has arrived.

    Science.gov (United States)

    Paulson, Kristjan; Gilpin, Scott G; Shpiruk, Tanner A; Anjos, Karla; Tulloch, Marie; Giftakis, Angleine; Blankstein, Anna R; Szwajcer, David; Wall, Donna A

    2015-08-01

    Most blood products are infused at the time of transfusion through a standard blood filter, designed to capture macroaggregates and cellular debris that might be harmful to the patient if infused. Hematopoietic stem cell products are not universally filtered, likely due to concern about loss of viable stem cells in the filtration process. We conducted a two-phase study to better understand the safety of routine filtration. First, surplus cryopreserved stem cell products were thawed and filtered, with markers of viability and potency measured. Second, routine filtration was implemented as part of routine practice at our center, and date of neutrophil and platelet (PLT) recovery was compared to historical controls. In the first phase, there was no difference seen in any markers of viability or potency for products after routine filtration. Based on those results, routine filtration was implemented. There was no difference in neutrophil or PLT engraftment. Thus, in this study, routine filtration did not impact the number of viable stem cells and did not delay engraftment. Given the very real harm posed by infusion of macroaggregates and cellular debris, and no clear disadvantage to filtration, routine filtration of stem cell products should be considered the standard of care. © 2015 AABB.

  7. Penetration of sub-micron aerosol droplets in composite cylindrical filtration elements

    NARCIS (Netherlands)

    Geurts, Bernardus J.; Pratte, Pascal; Stolz, S.; Stabbert, Regina; Poux, Valerie; Nordlund, Markus; Winkelmann, Christoph

    Advection–diffusion transport of aerosol droplets in composite cylindrical filtration elements is analyzed and compared to experimental data. The penetration, characterizing the fraction of droplets that passes through the pores of a filtration element, is quantified for a range of flow rates. The

  8. Self-assembled nanowire arrays as three-dimensional nanopores for filtration of DNA molecules.

    Science.gov (United States)

    Rahong, Sakon; Yasui, Takao; Yanagida, Takeshi; Nagashima, Kazuki; Kanai, Masaki; Meng, Gang; He, Yong; Zhuge, Fuwei; Kaji, Noritada; Kawai, Tomoji; Baba, Yoshinobu

    2015-01-01

    Molecular filtration and purification play important roles for biomolecule analysis. However, it is still necessary to improve efficiency and reduce the filtration time. Here, we show self-assembled nanowire arrays as three-dimensional (3D) nanopores embedded in a microfluidic channel for ultrafast DNA filtration. The 3D nanopore structure was formed by a vapor-liquid-solid (VLS) nanowire growth technique, which allowed us to control pore size of the filtration material by varying the number of growth cycles. λ DNA molecules (48.5 kbp) were filtrated from a mixture of T4 DNA (166 kbp) at the entrance of the 3D nanopore structure within 1 s under an applied electric field. Moreover, we observed single DNA molecule migration of T4 and λ DNA molecules to clarify the filtration mechanism. The 3D nanopore structure has simplicity of fabrication, flexibility of pore size control and reusability for biomolecule filtration. Consequently it is an excellent material for biomolecular filtration.

  9. Effect of filtration mode and backwash water on hydraulically irreversible fouling of ultrafiltration membrane.

    Science.gov (United States)

    Chang, Haiqing; Liu, Baicang; Liang, Heng; Yu, Huarong; Shao, Senlin; Li, Guibai

    2017-07-01

    To investigate the effect of filtration mode and backwash water on ultrafiltration (UF) membrane performance, total fouling index (TFI) and hydraulic irreversible fouling index (HIFI) for constant pressure (CP) filtration and constant flux (CF) filtration were compared. Kaolin, humic acid (HA) and sodium alginate (SA) solutions were used as feed solutions, and then the fouled membranes were backwashed with UF permeate or ultrapure water. Results showed that when the kaolin solution was filtrated, the filtration mode had a limited effect on the membrane fouling, and low TFI and HIFI were observed. When HA and SA solutions were filtrated, the TFI of UF under CP mode was comparable to or slightly higher than that under CF mode. Higher TFI was observed at a hydrophobic membrane, a high filtration strength, a high feed concentration, a low pH, a high ionic strength, and a low Ca2+ concentration. When the UF permeate was used as the backwash water, the HIFI for the UF operated under CF mode was significantly less than that under CP mode. Low irreversible fouling was obtained when the ultrapure water was used for backwashing, and the HIFI for the UF under different filtration modes was almost identical. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Theoretical comparison of filtration by the renal glomerulus and artificial membranes.

    Science.gov (United States)

    Tsuji, M; Sakai, K

    1999-01-01

    Improvement in filtration performance of artificial membranes will be possible if their structure mimics the renal glomerulus. Blood filtration with glomerular capillary and artificial membranes was, therefore, modeled to clarify the effects of their structure on filtration rates. Filtration rates were obtained by dividing membrane modules axially into a number of sections and using a calculus of finite differences. The modules were assumed to be composed of straight hollow fibers arranged in parallel, with a membrane surface area of 1.5 m2. The mean transmembrane pressure (TMP) was assumed to be too low for a protein gel layer to form on the membrane surface. A decrease in the inner diameter of membrane hollow fibers led to an increase in filtration rate because of an increased film mass transfer coefficient. A decrease in hollow fiber length also produced an increase in filtration rate because of decreased axial TMP drop. The glomerular capillary has a higher filtration rate than artificial membranes because of the low TMP drop and the low osmotic pressure at the membrane surface. Decreasing both the inner diameter and the length of the hollow fibers is effective in increasing the filtration rate at constant TMP.

  11. Process analysis and optimization of direct horizontal-row roughing filtration

    NARCIS (Netherlands)

    Ahsan, T.

    1995-01-01

    There is a growing demand for appropriate water treatment technology for towns and small cities in developing countries. This study developed a pretreatment technology for highly turbid river water, called direct horizontal-flow roughing filtration, by combining the principles of direct filtration

  12. Introduction of filtration systems in container nurseries for nonchemical elimination of Phytophthora spp. from irrigation water

    Science.gov (United States)

    Thorsten Ufer; Heinrich Beltz; Thomas Brand; Katrin Kaminski; Ralf Lüttmann; Martin Posner; Stefan Wagner; Sabine Werres; Hans-Peter Wessels

    2006-01-01

    In a 3-year project the elimination of Phytophthora spp. from the recirculation water with different kinds of filtration systems will be tested under commercial conditions in container nurseries. First results indicate that the filtration systems eliminate Phytophthora spp. from the water.

  13. Resolution of the three dimensional structure of components of the glomerular filtration barrier

    DEFF Research Database (Denmark)

    Arkill, Kenton P; Qvortrup, Klaus; Starborg, Tobias

    2014-01-01

    The human glomerulus is the primary filtration unit of the kidney, and contains the Glomerular Filtration Barrier (GFB). The GFB had been thought to comprise 3 layers - the endothelium, the basement membrane and the podocyte foot processes. However, recent studies have suggested that at least two...

  14. Spunlaced and chemically bonded nonwovens for filtration applications: Performance evaluation and comparison

    CSIR Research Space (South Africa)

    Boguslavsky, L

    2008-11-01

    Full Text Available The main function of textile filter media in air filtration is to control air pollution. Air filtration plays an important role in improving air quality and hygiene. The demands for air quality and hygiene at work places have increased greatly due...

  15. 75 FR 28295 - Cummins Filtration, Including On-Site Leased Workers From Manpower and Spherion Staffing...

    Science.gov (United States)

    2010-05-20

    ... Employment and Training Administration Cummins Filtration, Including On-Site Leased Workers From Manpower and... workers of Cummins Filtration, including on-site leased workers from Manpower, Lake Mills, Iowa. The... engaged in the production of oil and fuel filters, Stratpore media and other metal components for engines...

  16. Measurement of water filtration in skeletal muscle in man by an osmotic transient method

    DEFF Research Database (Denmark)

    Palm, T; Nielsen, S L; Lassen, N A

    1983-01-01

    Water filtration in the human forearm was determined with a new method using a hyperoncotic transient of albumin solution infused into the brachial artery. Baseline dilution of labelled albumin in deep forearm vein plasma in excess of the contribution from arterial blood and from infusate...... was assumed to originate from extravascular water filtered into the blood by the transient. The filtration coefficient (Fc) was determined as the ratio between filtered water and increase in colloid osmotic pressure in the blood samples, and gives the filtrative water permeability in the exchange areas...... of the microcirculation. In 10 normal volunteers, Fc was 0.00082 ml (ml mmHg)-1 (SD=0.00007). Multiplication of Fc by plasma flow in the forearm gave a filtration capacity (Kf) of 0.0036 ml (100 ml tissue min mmHg)-1 (SD=0.00137). This filtration capacity (Kf) represents that of fast flowing regions in the forearm...

  17. Continuous Processing of Active Pharmaceutical Ingredients Suspensions via Dynamic Cross-Flow Filtration.

    Science.gov (United States)

    Gursch, Johannes; Hohl, Roland; Toschkoff, Gregor; Dujmovic, Diana; Brozio, Jörg; Krumme, Markus; Rasenack, Norbert; Khinast, Johannes

    2015-10-01

    Over the last years, continuous manufacturing has created significant interest in the pharmaceutical industry. Continuous filtration at low flow rates and high solid loadings poses, however, a significant challenge. A commercially available, continuously operating, dynamic cross-flow filtration device (CFF) is tested and characterized. It is shown that the CFF is a highly suitable technology for continuous filtration. For all tested model active pharmaceutical ingredients, a material-specific strictly linear relationship between feed and permeate rate is identified. Moreover, for each tested substance, a constant concentration factor is reached. A one-parameter model based on a linear equation is suitable to fully describe the CFF filtration performance. This rather unexpected finding and the concentration polarization layer buildup is analyzed and a basic model to describe the observed filtration behavior is developed. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  18. Derivation of total filtration thickness for diagnostic x-ray source assembly.

    Science.gov (United States)

    Sekimoto, Michiharu; Katoh, Yoh

    2016-08-21

    The method defined by the IEC 60522 for determining the inherent filtration of an x-ray source device is applicable only for a limited range of tube voltage. Because the users cannot legally remove the x-ray movable diaphragm of the x-ray source device, total filtration, which is the sum of the additional filtration diaphragm movable for specific filtration and x-ray, cannot be measured. We develop a method for simply obtaining the total filtration for different tube voltage values. Total filtration can be estimated from a ratio R' of the air kerma [Formula: see text], which is measured with an Al plate with thickness T, and [Formula: see text] measured without an Al plate. The conditions of the target material of the x-ray source device are then entered into the Report 78 Spectrum Processor to calculate the air kerma K x and K x+T for Al thicknesses x and (x  +  T), respectively, to obtain R. The minimum value of x, which is the difference between the R and R', is the total filtration of the x-ray source device. The total filtration calculated using the industrial x-ray source device was within  ±1% in the 40-120 kV range. This method can calculate the total filtration using air kerma measurements with and without the Al plate. Therefore, the load on the x-ray tube can be reduced, and preparation of multiple Al plates is not necessary. Furthermore, for the 40-120 kV tube voltage range, the user can easily measure the total filtration.

  19. Understanding Deep Bed Filtration by Direct Micro-scale Particulate Flow Modelling

    Science.gov (United States)

    Mirabolghasemi, M.; Prodanovic, M.

    2013-12-01

    Filtration of suspensions through porous beds occurs in a variety of applications such as drilling mud infiltration into rock formations and waste water treatment. Accurate modelling of filtration through porous media on macroscopic scale often requires a precise estimate of the filtration coefficient, which reflects the fraction of particles that get retained in the filter medium. A large number of deep bed filtration models assume a constant entrapment rate without taking into account the rate of particle release back into the flow. In addition, the available models often assume instantaneous entrapment, which ignores particle rolling. These assumptions lead to an almost static description of filtration phenomenon, which is in fact highly dynamic in nature. In this study we used a micro-scale simulation approach to understand the filtration of suspensions through a sphere pack. We applied a semi-coupled CFD-DEM method to directly model the fluid and particulate flow through the extracted pore space. The accuracy of the geometrical description of the flow domain was tested by calculating its porosity and permeability and comparing those to measured values. The results of the simulation provide the distribution of particle and fluid velocities throughout the filtration process. These velocity distributions show that under our simulation conditions, a significant portion of particles travel with a velocity 4 to 5 orders of magnitude slower than the average fluid velocity, which indicates that particle rolling is not negligible. Based on these results we propose a modified definition of filtration coefficient and estimate its values. Overall, this study provides an improved insight into deep bed filtration and reveals the absence of a granular phase flow equation in the existing deep bed filtration formulation. Finally, while we worked with sphere packing for this initial study, the simulation can take any pore space described by a binary (segmented) image and is

  20. Evaluation of Filtration and UV Disinfection for Inactivation of Viruses in Non-Community Water Systems in Minnesota

    Science.gov (United States)

    This study evaluated filtration and disinfection processes for removal and inactivation of pathogens in non-community water systems (NCWS) in two surface water supplies. Pretreatment systems included 1) pressure sand filtration, and 2) granular activated carbon adsorption, and 3...

  1. The Role of Filtration in Maintaining Clean Heat Exchanger Coils

    Energy Technology Data Exchange (ETDEWEB)

    Li Yang; James E. Braun; Eckhard A. Groll

    2004-06-30

    The main purpose of the study was to investigate the role of filtration in maintaining clean heat exchanger coils and overall performance. Combinations of 6 different levels of filtration (MERV 14, 11, 8, 6, 4, and no filter) and 4 different coils (an eight-row lanced-fin coil, HX8L), (an eight-row wavy-fin coil, HX8W), (a four-row lanced-fin coil, HX4L) and (a two-row lanced-fin coil, HX2L) were tested at 4 different air velocities (1.52, 2.03, 2.54,3.05 m/s (300, 400, 500, 600 ft/min)). The fouled conditions were obtained after injection of 600 grams of ASHRAE standard dust upstream of the filter/coil combination. This magnitude of dust is representative of a year of normal operation for an air conditioning system. The air-side pressure drops of the coils and filters and air-side heat transfer coefficients of the coils were determined from the measurements under the clean and fouled conditions. Depending upon the filter and coil test, the coil pressure drops increased in the range of 6%-30% for an air velocity at 2.54 m/s (500 ft/min). The impact was significantly greater for tests performed without a filter. The largest relative effect of fouling on pressure drop occurs for coils with fewer rows and having lanced fins. Coils with a greater number of rows can hold more dust so that a fixed amount of dust has a relatively smaller impact. The impact of fouling on air-side heat transfer coefficients was found to be relatively small. In some cases, heat transfer was actually enhanced due to additional turbulence caused by the presence of dust. The experimental results for pressure drops and heat transfer coefficients were correlated and the correlations were implemented within computer models of prototypical rooftop air conditioners and used to evaluate the impact of fouling on cooling capacity and EER. The equipment cooling capacity is reduced with fouling primarily because of a decrease in air flow due to the increase pressure drop rather than due to changes in h

  2. DESTRUCTION OF XENOBIOTICS BY CULTURE FILTRATE FROM XYLOTROPHIC BASIDIOMYCETES

    Directory of Open Access Journals (Sweden)

    O. V. Fedotov

    2015-11-01

    Full Text Available The article deals with the efficiency of pollutants biodegradation by xylotrophic basidiomycetes submerged cultures grown on standard glucose-peptone medium (GPM. The efficiency of pollutants biodegradation was determined by the model compound – dye Methyl Orange. The purpose of the work is screening of 19 species 81 strains xylotrophic basidiomycetes cultures on the indicator of the dye oxidative degradation efficiency and exploring the possibility of induction of this indicator by modifying the culture medium. The biodegradation efficiency was determined by following method. Assigned amount of culture filtrate (experiment or medium (control was added to the 0.001% solution of Methyl Orange in sodium acetate buffer. pH of the reaction mixture was 4.4 units. Samples were incubated at +40°C for 48 hours. Then pH of the reaction mixture was set up at 3.1 units using sodium acetate buffer and the optical density of solutions at a wavelength of 506 nm was measured. The efficiency of biodegradation was calculated by the difference of the optical density of control and experiment as a percentage. The most promising strains – F. velutipes F-1105, P. eryngii P-er, T. hirsuta Th-11 and D. quercina Dq-08 were selected. The composition of the glucose-peptone medium was modified for these strains by the introduction in the medium lignosulfonate, Tween 80, Kirk’s minerals solution and selecting the concentration of these components. According to the study for the purpose of pollutants degradation it is advisable to cultivate  F. velutipes F-1105 strain on modified GPM, which further comprises at 1 l: lignosulfonate – 3.5 g; Tween 80 – 1.0 g, Kirk’s minerals solution – 70 ml; P. eryngii P-er strain – 5.0 g, 1.0 g, 70 ml; T. hirsuta Th-11 strain – 5.0 g, 1.0 g, 105 ml; and D. quercina Dq-08 strain – 6.5 g, 1.0 g, 105 ml, respectively. This allowed to increase the model compound degradation efficiency by the culture filtrate of strain F

  3. DESTRUCTION OF XENOBIOTICS BY CULTURE FILTRATE FROM XYLOTROPHIC BASIDIOMYCETES

    Directory of Open Access Journals (Sweden)

    Fedotov O. V.

    2015-12-01

    Full Text Available The article deals with the efficiency of pollutants biodegradation by xylotrophic basidiomycetes submerged cultures grown on standard glucose-peptone medium (GPM. The efficiency of pollutants biodegradation was determined by the model compound – dye Methyl Orange. The purpose of the work is screening of 19 species 81 strains xylotrophic basidiomycetes cultures on the indicator of the dye oxidative degradation efficiency and exploring the possibility of induction of this indicator by modifying the culture medium. The biodegradation efficiency was determined by following method. Assigned amount of culture filtrate (experiment or medium (control was added to the 0.001% solution of Methyl Orange in sodium acetate buffer. pH of the reaction mixture was 4.4 units. Samples were incubated at +40°C for 48 hours. Then pH of the reaction mixture was set up at 3.1 units using sodium acetate buffer and the optical density of solutions at a wavelength of 506 nm was measured. The efficiency of biodegradation was calculated by the difference of the optical density of control and experiment as a percentage. The most promising strains – F. velutipes F-1105, P. eryngii P-er, T. hirsuta Th-11 and D. quercina Dq-08 were selected. The composition of the glucose-peptone medium was modified for these strains by the introduction in the medium lignosulfonate, Tween 80, Kirk’s minerals solution and selecting the concentration of these components. According to the study for the purpose of pollutants degradation it is advisable to cultivate F. velutipes F-1105 strain on modified GPM, which further comprises at 1 l: lignosulfonate – 3.5 g; Tween 80 – 1.0 g, Kirk’s minerals solution – 70 ml; P. eryngii P-er strain – 5.0 g, 1.0 g, 70 ml; T. hirsuta Th-11 strain – 5.0 g, 1.0 g, 105 ml; and D. quercina Dq-08 strain – 6.5 g, 1.0 g, 105 ml, respectively. This allowed to increase the model compound degradation efficiency by the culture filtrate of strain F

  4. Efficacy of Syringe Filtration for the Selective Isolation of Campylobacter from Chicken Carcass Rinse.

    Science.gov (United States)

    Chon, Jung-Whan; Kim, Hong-Seok; Kim, Dong-Hyeon; Kim, Young-Ji; Sung, Kidon; Kim, Hyunsook; Seo, Kun-Ho

    2017-06-01

    We investigated the efficacy of syringe filtration for selective isolation of Campylobacter from chicken carcass rinse by combining syringe filtration with the conventional culture method. Whole chicken carcass rinses were incubated in Bolton enrichment broth, set aside or subjected to syringe filtration, and streaked on Campy-Cefex agar with or without cefoperazone antibiotic supplement. Compared with the conventional method without filtration, 0.65-μm-pore-size syringe filtration resulted in a significantly higher number of Campylobacter-positive samples (23.8 to 37.5% versus 70.0 to 72.5%; P Campylobacter (93.8% versus 6.3 to 26.3%), and a lower growth index (1 = growth of a few colonies; 2 = growth of colonies on about half of the plate; and 3 = growth on most of the plate) for competing microbiota (2.9 to 3.0 versus 1.2 to 1.4). When syringe filtration was applied, agar plates containing the antibiotic had significantly less contamination (6.3% versus 26.3%; P Campylobacter isolation rate was similar (P > 0.05). Syringe filtration combined with conventional enrichment improved the rate and selectivity of Campylobacter isolation from chicken carcasses.

  5. [Niobium filtration in dental radiology. Effects on image quality and on dosage].

    Science.gov (United States)

    Bianchi, S D; Giovannetti, P; Albrito, F

    1997-06-01

    The necessity of reducing the radiation dose to the patient in diagnostic radiology according to the ALARA guideline established by the ICRP has stimulated the research on additional filtration systems capable of removing the low-energy photons increasing the dose and worsening image quality. Very few literature studies deal with the effects of niobium filtration on image quality in dental radiography with the use of modulation transfer function (MTF) and square wave response function (SWRF). Only one study has considered those effects measuring dose absorption in an anthropomorphic phantom. 1) to study the effects of a 30 microns additional niobium filter on image quality using the SWRF; 2) to compare the doses absorbed in vivo during a complete radiographic survey of the mouth, both with and without niobium filtration. Qualitative studies led us to conclude that niobium filtration does not significantly worsen radiographic image quality. The following doses were measured in the exposures with niobium filtration: 1678 microGy to 6000 microGy (intraoral doses) and 75 microGy to 3643 microGy (skin doses). The comparison with the doses measured during the exposures made with conventional filtration indicates that dose reduction is not significantly advantageous relative to risk reduction. In conclusion, additional niobium filtration is not advisable in dental radiology, also because of the filter cost and of the increased wear of the unit.

  6. Influence of filtration velocity on DON variation in BAF for micropolluted surface water treatment.

    Science.gov (United States)

    Ma, Teng-Fei; Chen, You-Peng; Kang, Jia; Gao, Xu; Guo, Jin-Song; Fang, Fang; Zhang, Xiao-Tian

    2016-12-01

    Biological aerated filters (BAFs) are widely used for the treatment of micropolluted surface water. However, the biological process produces dissolved organic nitrogen (DON), which, as precursors of nitrogenous disinfection by-products, pose potential threats to drinking water safety. Therefore, to control DON in BAF effluent, it is necessary to study the influence of BAF operation parameters on DON production. In this study, the influence of filtration velocity in a BAF on DON production was investigated. Under different filtration velocity (0.5, 2, and 4 m/h) conditions, profiles of DON concentrations along the media layer were measured. The profile at a filtration velocity of 0.5 m/h showed a decreasing trend, and the ones under filtration velocities of 2 and 4 m/h fluctuated in a small range (from 0.1 to 0.4 mg/L). Moreover, the relatively high filtration velocities of 2 and 4 m/h resulted in a lower level of DON concentration. Additionally, 3D excitation-emission matrix fluorescence spectroscopy was used to characterize DON. It is found that the patterns of DON at a relatively high filtration velocity condition (4 m/h) were obviously different from the ones under low filtration velocity conditions (0.5 and 2 m/h).

  7. Need for Estimating the Glomerular Filtration Rate to Assess Renal Function

    Directory of Open Access Journals (Sweden)

    José Antonio Chipi Cabrera

    2013-11-01

    Full Text Available Background: plasma creatinine alone is not useful for assessing renal function; patients with normal creatinine values can experience a significant decline in the glomerular filtration rate, hindering early detection of renal function impairment. Objective: to assess renal function by determining the plasma creatinine compared to the glomerular filtration rate estimated through the Cockcroft -Gault, MDRD -4 and CKD- Epi formulas. Methods: the database of a population-based epidemiological study conducted in the Isle of Youth since November 2004 was used. It involved 897 patients, 342 women and 555 men. Plasma creatinine and glomerular filtration rate were estimated by means of 3 formulas. Renal function was considered normal when serum creatinine values were <123 µmol/l for women and <132 µmol/l for men and glomerular filtration rate > 60 ml/min. Results: plasma creatinine was stable in the four age groups, with a mean of 100.68 ± 38.01, glomerular filtration rate decreased with increasing age in the three formulas. Correlation coefficient between plasma creatinine values and glomerular filtration rate for each formula expressed a linear relationship with r [CG formula 0.639 (p = 0.000], [0.672 MDRD -4 (p = 0.000] and [0.939 CKD – Epi formula (p = 0.000]. Conclusions: the utility of the methods for estimating the glomerular filtration rate was demonstrated, leading to the detection of the renal function impairment before the serum creatinine level increases.

  8. Detection of damage of a filter by visualization of filtration process

    Directory of Open Access Journals (Sweden)

    Bílek P.

    2014-03-01

    Full Text Available This paper deals with testing of filters on the basis of visualization of filtration process. A filtration material can be damaged by flow of the filtered medium, high pressure drop and long-term adverse conditions. These negative effects can cause extensive damage of the filtration textile and filtration efficiency decreases. The filter can be also fractured during manufacturing, processing or by improper manipulation. A testing of a purposely damaged filtration textile is described in the article. Experiments were performed on the filtration setup which permits an optical entrance to the position where a sample of filter is placed. A laser sheet is directed into this place. Scattered light from seeding particles in front of and behind the filter is captured by a digital camera. Images from the camera are analyzed and the filtration efficiency versus time and also versus position can be obtained. Measuring chain including light scattering theory and measuring of light intensity by a digital camera are also discussed in the article.

  9. Detection of damage of a filter by visualization of filtration process

    Science.gov (United States)

    Bílek, P.; Šidlof, P.

    2014-03-01

    This paper deals with testing of filters on the basis of visualization of filtration process. A filtration material can be damaged by flow of the filtered medium, high pressure drop and long-term adverse conditions. These negative effects can cause extensive damage of the filtration textile and filtration efficiency decreases. The filter can be also fractured during manufacturing, processing or by improper manipulation. A testing of a purposely damaged filtration textile is described in the article. Experiments were performed on the filtration setup which permits an optical entrance to the position where a sample of filter is placed. A laser sheet is directed into this place. Scattered light from seeding particles in front of and behind the filter is captured by a digital camera. Images from the camera are analyzed and the filtration efficiency versus time and also versus position can be obtained. Measuring chain including light scattering theory and measuring of light intensity by a digital camera are also discussed in the article.

  10. Long-Term Leukocyte Filtration Should Be Avoided during Extracorporeal Circulation

    Science.gov (United States)

    Tang, Jiali; Tao, Kaiyu; Zhou, Jing; Zhang, Chongwei; Gong, Lina; Luo, Nanfu

    2013-01-01

    Filtration during extracorporeal circulation (ECC) not only removes but also activates leukocytes; therefore, long-term leukocyte filtration may cause adverse effects. In the present study, we tested this hypothesis by priming ECC with 300 mL of canine blood and examining filtration effects in 3 groups (n = 6 each) during 60 min ECC. In the control group (Group C) blood was filtrated with an arterial filter for 60 min; in long-term (Group L) and short-term (Group S) groups, blood was filtrated with a leukocyte filter for 60 and 5 min. We found that about 90% of leukocytes were removed after 5 min of filtration in both Groups L and S. Although leukocyte count continued to reduce, mean fluorescent intensities of CD11/CD18, free hemoglobin, and neutrophil elastase increased in Group L and were higher than those in Groups C and S at 60 min. Leukocyte rupture, cytoplasmic leakage, and circulating naked nuclei were also found in Group L. The data support our hypothesis that long-term filtration can induce inflammation and lead to leukocyte destruction. PMID:24453424

  11. Modeling of particle removal in the first coarse media of direct horizontal-flow roughing filtration.

    Science.gov (United States)

    Ahn, H W; Park, N S; Kim, S; Park, S Y; Wang, C K

    2007-03-01

    Horizontal-Flow Roughing Filtration (HRF) is an alternative pretreatment method e.g. prior to Slow Sand Filtration (SSF). However, some of its limitations are that the effluent quality drops drastically at higher turbidity (>200NTU) and at higher filtration rate (>1 m h(-1)). To overcome these drawbacks, we suggested Direct Horizontal-Flow Roughing Filtration (DHRF), which is a modified system of Horizontal-Flow Roughing Filtration (HRF) by addition of a low dose of coagulant prior to filtration. To optimize the DHRF configuration, a conceptual and mathematical model for the coarse compartment has been developed in analogy with multi-plate settler. Data from simple column settling test can be used in the model to predict the filter performance. Furthermore, the model developed herein has been validated by successive experiments. The conventional column settling test has been found to be handy and useful to predict the performance of DHRF for different raw water characteristics (e.g. coagulated or uncoagulated water, different amounts of organic matter, etc.) and different initial process conditions (e.g. coagulant dose, mixing time and intensity, etc.). An optimum filter design for the coarse compartment (grain size 20 mm) has been found to be of 3m h(-1) filtration rate with filter length of 4-4.5 m.

  12. The effects of filtration on protein nucleation in different growth media.

    Science.gov (United States)

    Hirschler, J.; Charon, M. H.; Fontecilla-Camps, J. C.

    1995-01-01

    Filtration effects of turkey egg white lysozyme solution (TEWL) prior to subjecting it to crystallization conditions are investigated. Filtering TEWL solution and crystallizing it in ungelled media significantly decreased the number of conditions yielding crystals. This decrease dependent on the membrane cut-off used for filtration. From this, the postulated factors aiding in nucleation are estimated to be 0.17 microns in diameter. The existence of these factors was verified by the procedure of reversed filtration: filtered solutions passed through their inverted filter membrane a second time lead to improved crystallization results. The effect of aging of the TEWL solution prior to subjecting it to ungelled crystallization conditions was also verified. We did not find any time-dependent change in the size or the number of crystals per drop. Repeating the filtration experiments in agarose-gelled crystallization media showed that the influence of filtration on the crystallization outcome was significantly diminished. Far better crystallization results were obtained compared to ungelled media. However, there is a certain aging effect linked to filtration in gelled media. Different crystallization results were obtained depending on whether filtration was performed before or after aging and subsequent crystallization. This suggests a secondary time-dependent effect. PMID:8580848

  13. Pretreatment chemistry for dual media filtration: model simulations and experimental studies.

    Science.gov (United States)

    Shin, J Y; O'Melia, C R

    2006-01-01

    Laboratory dual media filtration experiments were conducted (a) in direct filtration mode using model raw water moderate in turbidity and low in DOC, and (b) in conventional filtration mode treating water moderate in turbidity and high in DOC. Model simulations of filter performance for the removal of particles provided hypotheses for the experimental studies of dual media filtration. An increase in alum dose in direct filtration mode, while improving filter performance, also showed some disadvantages, including rapid development of head loss. Suboptimal dose in direct filtration significantly impaired the filter performance. In conventional mode, the effect of alum dose on the filter performance, while obvious, was not as dramatic as in direct filtration. Ripening indicated by particle counts occurred earlier than by turbidity and breakthrough of particle counts started earlier than breakthrough of turbidity, suggesting that turbidity can be used as a more conservative monitor of filter performance during the ripening period to minimise the risk of passage of small particles, while particle counts can be considered a more sensitive indicator of deteriorating filter performance during the breakthrough period. The lower sand layer served as a multiple barrier for particle when the performance of the anthracite layer was not effective.

  14. Establishment and application of milk fingerprint by gel filtration chromatography.

    Science.gov (United States)

    Gao, P; Li, J; Li, Z; Hao, J; Zan, L

    2016-12-01

    Raw milk adulteration frequently occurs in undeveloped countries. It not only reduces the nutritional value of milk, but it is also harmful to consumers. In this paper, we focused on investigating an efficient method for the quality control of raw milk protein. A gel filtration chromatography (GFC) fingerprint method combined with chemometrics was developed for fingerprint analysis of raw milk. To optimize the GFC conditions, milk fat was removed by centrifugation, and GFC analysis was performed on a Superdex 75 10/300GL column (Just Scientific, Shanghai, China) with 0.2 M NaH2PO4-Na2HPO4 buffer (pH 7.0) as the mobile phase. The flow rate was 0.5mL/min, and the detection wavelength was set at 280 nm. Ten batches of 120 raw milk samples were analyzed to establish the GFC fingerprint under optimal conditions. Six major peaks common to the chromatogram of each raw milk sample were selected for fingerprint analysis, and the characteristic peaks were used to establish a standard chromatographic fingerprint. Principal component analysis was then applied to classify GFC information of adulterated milk and raw milk, allowing adulterated samples to be effectively screened out from the raw milk in principal component analysis scores plot. The fingerprint method demonstrates promising features in detecting milk protein adulteration. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. [Estimation of glomerular filtration rate using weight/creatinine formula].

    Science.gov (United States)

    Fernández-Fresnedo, Gema; Martín de Francisco, Angel Luis; Rodrigo Calabia, Emilio; Ruiz San Millán, Juan Carlos; Sanz de Castro, Saturnino; Arias Rodríguez, Manuel

    2003-04-12

    The correct management of patients with chronic renal disease depends on an early diagnosis. The aim of this study was to evaluate the usefulness, in the daily clinical practice, of the weight/creatinine formula as an indirect measurement of glomerular filtration. 1,025 ambulatory patients were referred to the Nephrology Laboratory for basic blood and urine analysis. Creatinine clearance was calculated with the standard formula. A good correlation between the creatinine clearance adjusted for the corporal surface and that estimated by the weight/creatinine formula was observed, especially when creatinine levels were between 1.5-3 mg/dl and patients were older than 60 years. The mean difference between both methods was 6.3 (14.5) ml/min for males and 2.4 (10.5) ml/min for females. The weight/creatinine formula had a sensitivity of 91% and a specificity of 80% to detect a clearance below 50 ml/min. The weight/creatinine formula underestimates the clearance for normal creatinine values but fits quite well for creatinine levels between 1.5-3 mg/dl, mainly in patients older than 60 years. Although the estimation of clearance through this formula could be inaccurate, in most cases this is clinically irrelevant. Moreover, such a simple formula could avoid potential mistakes appearing at the time of evaluating renal function only by the serum creatinine.

  16. Filtration of Carbon Particulate Emissions from a Plasma Pyrolysis Assembly

    Science.gov (United States)

    Agui, Juan H.; Green, Robert; Vijayakumar, R.; Berger, Gordon; Greenwood, Zach; Abney, Morgan; Peterson, Elspeth

    2016-01-01

    NASA is investigating plasma pyrolysis as a candidate technology that will enable the recovery of hydrogen from the methane produced by the ISS Sabatier Reactor. The Plasma Pyrolysis Assembly (PPA) is the current prototype of this technology which converts the methane product from the Carbon Dioxide Reduction Assembly (CRA) to acetylene and hydrogen with 90% or greater conversion efficiency. A small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on several options for filtering out the carbon particulate emissions from the PPA exit gas stream. The filtration technologies and concepts investigated range from fibrous media to monolithic ceramic and sintered metal media. This paper describes the different developed filter prototypes and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC. In addition, characterization data on the generated carbon particulates, that help to define filter requirements, are also presented.

  17. ALTERNATE HIGH EFFICIENCY PARTICULATE AIR (HEPA) FILTRATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Bishop; Robert Goldsmith; Karsten Nielsen; Phillip Paquette

    2002-08-16

    In Phase IIA of this project, CeraMem has further developed and scaled up ceramic HEPA filters that are appropriate for use on filtration of vent gas from HLW tanks at DOE sites around the country. This work included procuring recrystallized SiC monoliths, developing membrane and cement materials, and defining a manufacturing process for the production of prototype full sizes HEPA filters. CeraMem has demonstrated that prototype full size filters can be manufactured by producing 9 full size filters that passed DOP aerosol testing at the Oak Ridge Filter Test Facility. One of these filters was supplied to the Savannah River Technical Center (SRTC) for process tests using simulated HLW tank waste. SRTC has reported that the filter was regenerable (with some increase in pressure drop) and that the filter retained its HEPA retention capability. CeraMem has also developed a Regenerable HEPA Filter System (RHFS) design and acceptance test plan that was reviewed by DOE personnel. The design and acceptance test plan form the basis of the system proposal for follow-on work in Phase IIB of this project.

  18. Evaluation of gravimetric techniques to estimate the microvascular filtration coefficient.

    Science.gov (United States)

    Dongaonkar, R M; Laine, G A; Stewart, R H; Quick, C M

    2011-06-01

    Microvascular permeability to water is characterized by the microvascular filtration coefficient (K(f)). Conventional gravimetric techniques to estimate K(f) rely on data obtained from either transient or steady-state increases in organ weight in response to increases in microvascular pressure. Both techniques result in considerably different estimates and neither account for interstitial fluid storage and lymphatic return. We therefore developed a theoretical framework to evaluate K(f) estimation techniques by 1) comparing conventional techniques to a novel technique that includes effects of interstitial fluid storage and lymphatic return, 2) evaluating the ability of conventional techniques to reproduce K(f) from simulated gravimetric data generated by a realistic interstitial fluid balance model, 3) analyzing new data collected from rat intestine, and 4) analyzing previously reported data. These approaches revealed that the steady-state gravimetric technique yields estimates that are not directly related to K(f) and are in some cases directly proportional to interstitial compliance. However, the transient gravimetric technique yields accurate estimates in some organs, because the typical experimental duration minimizes the effects of interstitial fluid storage and lymphatic return. Furthermore, our analytical framework reveals that the supposed requirement of tying off all draining lymphatic vessels for the transient technique is unnecessary. Finally, our numerical simulations indicate that our comprehensive technique accurately reproduces the value of K(f) in all organs, is not confounded by interstitial storage and lymphatic return, and provides corroboration of the estimate from the transient technique.

  19. Integrated oxidation membrane filtration process - NOM rejection and membrane fouling.

    Science.gov (United States)

    Winter, J; Uhl, W; Bérubé, P R

    2016-11-01

    The extent and mechanisms by which organic matter in a solution can be retained and foul a membrane largely depends on the molecular weight of the material being filtered and the molecular weight cut-off (MWCO) of the membrane. The present study investigated the effect of the MWCO of a membrane and the molecular weight distribution of natural organic matter (NOM) in a source water on the increase in resistance to the permeate flux over time. Of particular interest was the effect of oxidation, applied prior to membrane filtration, on the predominant fouling mechanism. Oxidation can change the molecular weight distribution of organic matter in raw water, and therefore the ability of a membrane to retain this organic matter. Oxidation, using both ozonation and UV/H 2 O 2 , could effectively reduce the extent of fouling for higher MWCO membranes. However, neither oxidation approaches could effectively reduce the extent of fouling for lower MWCO membranes, likely because oxidation could not effectively oxidize lower molecular weight organic matter. Althoug the data indicated that the extent of fouling is increasing with the amount of DOC retained by the membrane, no statistically significant correlation was observed between these parameters. The results suggest that oxidation did not affect the predominant fouling mechanism. However, it did affect the molecular weight distribution of the organic matter retained by the membranes, and as a result, the resistance offered by the foulant cake layer. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Riverbank filtration: comparison of pilot scale transport with theory.

    Science.gov (United States)

    Gupta, Vishal; Johnson, W P; Shafieian, P; Ryu, H; Alum, A; Abbaszadegan, M; Hubbs, S A; Rauch-Williams, T

    2009-02-01

    Pilot-scale column experiments were conducted in this study using natural soil and river water from Ohio river to assess the removal of microbes of size ranging over 2 orders of magnitude, i.e., viruses (0.025-0.065 microm), bacteria (1-2 microm), and Cryptosporidium parvum oocysts (4-7 microm) under conditions representing normal operation and flood scour events. Among these different organisms, the bacterial indicators were transported over the longest distances and highest concentrations; whereas much greater retention was observed for smaller (i.e., viral indicators) and larger (i.e., Cryptosporidium parvum oocysts) microbes. These results are in qualitative agreement with colloid filtration theory (CFT) which predicts the least removal for micrometer size colloids, suggesting that the respective sizes of the organisms was a dominant control on their transport despite expected differences in their surface characteristics. Increased fluid velocity coupled with decreased ionic strength (representative of major flood events) decreased colloid retention, also in qualitative agreement with CFT. The retention of organisms occurred disproportionately near the source relative to the log-linear expectations of CFT, and this was true both in the presence and absence of a colmation zone, suggesting that microbial removal by the RBF system is not necessarily vulnerable to flood scour of the colmation zone.

  1. Standard filtration practices may significantly distort planktonic microbial diversity estimates.

    Science.gov (United States)

    Padilla, Cory C; Ganesh, Sangita; Gantt, Shelby; Huhman, Alex; Parris, Darren J; Sarode, Neha; Stewart, Frank J

    2015-01-01

    Fractionation of biomass by filtration is a standard method for sampling planktonic microbes. It is unclear how the taxonomic composition of filtered biomass changes depending on sample volume. Using seawater from a marine oxygen minimum zone, we quantified the 16S rRNA gene composition of biomass on a prefilter (1.6 μm pore-size) and a downstream 0.2 μm filter over sample volumes from 0.05 to 5 L. Significant community shifts occurred in both filter fractions, and were most dramatic in the prefilter community. Sequences matching Vibrionales decreased from ~40 to 60% of prefilter datasets at low volumes (0.05-0.5 L) to less than 5% at higher volumes, while groups such at the Chromatiales and Thiohalorhabdales followed opposite trends, increasing from minor representation to become the dominant taxa at higher volumes. Groups often associated with marine particles, including members of the Deltaproteobacteria, Planctomycetes, and Bacteroidetes, were among those showing the greatest increase with volume (4 to 27-fold). Taxon richness (97% similarity clusters) also varied significantly with volume, and in opposing directions depending on filter fraction, highlighting potential biases in community complexity estimates. These data raise concerns for studies using filter fractionation for quantitative comparisons of aquatic microbial diversity, for example between free-living and particle-associated communities.

  2. Evaluation of endotoxin retention by adsorptive-based filtration media.

    Science.gov (United States)

    O'Brien, Thomas P; Conway, Robert; Chen, Hsiao-Lin; Buckland, Kim

    2007-01-01

    Control of endotoxin contamination is an important issue in pharmaceutical and bioprocess manufacturing. Endotoxins can contaminate process intermediates used in pharmaceutical formulations, aqueous- and non-aqueous-based CIP fluids used in equipment and vial cleaning, and process fluids such as buffers used for chromatographic elution, diafiltration, and suspension of therapeutic protein-based drugs. A study was undertaken to evaluate the effectiveness of adsorptive-based depth and membrane filtration media in removing suspended endotoxin. The following variables were examined in order to determine their effects on endotoxin reduction: absorptive media type, residence time (flux), challenge solution pH, and interferences in endotoxin reduction as the result of challenge solution composition-water for injection, process buffer, and the presence of protein. The endotoxin removal capacities of the various media studied were also determined. The results of the study demonstrated differences in the effect on endotoxin removal of the variables evaluated. In addition, the results provide a strategy for conducting studies to select and validate an appropriate adsorptive filter media for control of endotoxin contamination.

  3. Standard filtration practices may significantly distort planktonic microbial diversity estimates

    Directory of Open Access Journals (Sweden)

    Cory Cruz Padilla

    2015-06-01

    Full Text Available Fractionation of biomass by filtration is a standard method for sampling planktonic microbes. It is unclear how the taxonomic composition of filtered biomass changes depending on sample volume. Using seawater from a marine oxygen minimum zone, we quantified the 16S rRNA gene composition of biomass on a prefilter (1.6 μm pore-size and a downstream 0.2 μm filter over sample volumes from 0.05 to 5 L. Significant community shifts occurred in both filter fractions, and were most dramatic in the prefilter community. Sequences matching Vibrionales decreased from ~40-60% of prefilter datasets at low volumes (0.05-0.5 L to less than 5% at higher volumes, while groups such at the Chromatiales and Thiohalorhabdales followed opposite trends, increasing from minor representation to become the dominant taxa at higher volumes. Groups often associated with marine particles, including members of the Deltaproteobacteria, Planctomycetes and Bacteroidetes, were among those showing the greatest increase with volume (4 to 27-fold. Taxon richness (97% similarity clusters also varied significantly with volume, and in opposing directions depending on filter fraction, highlighting potential biases in community complexity estimates. These data raise concerns for studies using filter fractionation for quantitative comparisons of aquatic microbial diversity, for example between free-living and particle-associated communities.

  4. Coupled plasma filtration-adsorption in Weil's syndrome: case report.

    Science.gov (United States)

    Moretti, R; Scarrone, S; Pizzi, B; Bonato, V; Vivaldi, N

    2011-08-01

    Weil's syndrome is a form of leptospirosis characterized by jaundice, renal failure and hemorrhagic diathesis. Its pathogenesis is related with the invasiveness of leptospires and with the subsequent systemic inflammatory response. Coupled plasma filtration-adsorption (CPFA) is a modality of extracorporeal blood purification in which plasma is separated from the whole blood and directed into a sorbent cartridge. Due to the ability of the sorbent agent to remove cytokines, CPFA has been proposed as an adjuvant treatment in septic shock. We report the case of a 27-year-old man with Weil's syndrome who was admitted to ICU with hypotension and anuria refractory to fluid therapy, ARDS, and hepatic involvement. The man needed intubation, mechanical ventilation and vasopressor infusion. CPFA was started early after the onset of shock. Five courses of CPFA were performed. Each course lasted for 10 h with 14 h interval. Weaning from vasopressors was achieved during the second course of CPFA (day 2 after admission). Weaning from ventilation was achieved on day 6. Interestingly, diuresis started during the first course of CPFA, with a creatinine clearance of 63 ml/min on day 8 and a normalization of the ratio urinary to plasma osmolality on day 28. The patient was discharged on day 11 and 28 from the Intensive Care Unit and hospital respectively.

  5. Covering link calculus and the bipolar filtration of topologically slice links.

    OpenAIRE

    Cha, Jae Choon; Powell, Mark

    2014-01-01

    The bipolar filtration introduced by T Cochran, S Harvey and P Horn is a framework for the study of smooth concordance of topologically slice knots and links. It is known that there are topologically slice 1–bipolar knots which are not 2–bipolar. For knots, this is the highest known level at which the filtration does not stabilize. For the case of links with two or more components, we prove that the filtration does not stabilize at any level: for any n, there are topologically slice links whi...

  6. Covering link calculus and the bipolar filtration of topologically slice links

    OpenAIRE

    Cha, Jae Choon; Powell, Mark

    2012-01-01

    The bipolar filtration introduced by T. Cochran, S. Harvey, and P. Horn is a framework for the study of smooth concordance of topologically slice knots and links. It is known that there are topologically slice 1-bipolar knots which are not 2-bipolar. For knots, this is the highest known level at which the filtration does not stabilize. For the case of links with two or more components, we prove that the filtration does not stabilize at any level: for any n, there are topologically slice links...

  7. A high filtration system with synthetic permeable media for wastewater reclamation.

    Science.gov (United States)

    Park, K Y; Maeng, S K; Kim, K; Kweon, J H; Ahn, K H

    2006-01-01

    A novel filtration process with synthetic permeable media was investigated for secondary effluent reclamation. Polyurethane was chosen as the filter medium among three tested media. Compressibility and up-flow velocity were changed to determine the optimum operation for the system. An equation was introduced to express the relationship between the removal efficiency and up-flow velocity. In a pilot study, the synthetic medium filtration with compression showed very stable effluent quality without clogging trouble, though the system operated with three times higher filtration rate and much longer backwashing interval than conventional systems.

  8. Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vagins, Mark R.

    2013-04-10

    Water Cherenkov detectors have been used for many years as inexpensive, effective detectors for neutrino interactions and nucleon decay searches. While many important measurements have been made with these detectors a major drawback has been their inability to detect the absorption of thermal neutrons. We believe an inexpensive, effective technique could be developed to overcome this situation via the addition to water of a solute with a large neutron cross section and energetic gamma daughters which would make neutrons detectable. Gadolinium seems an excellent candidate especially since in recent years it has become very inexpensive, now less than $8 per kilogram in the form of commercially-available gadolinium trichloride, GdCl{sub 3}. This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields a gamma cascade which would be easily seen in detectors like Super-Kamiokande. We have been investigating the use of GdCl{sub 3} as a possible upgrade for the Super-Kamiokande detector with a view toward improving its performance as a detector for atmospheric neutrinos, supernova neutrinos, wrong-sign solar neutrinos, reactor neutrinos, proton decay, and also as a target for the coming T2K long-baseline neutrino experiment. This focused study of selective water filtration and GdCl{sub 3} extraction techniques, conducted at UC Irvine, followed up on highly promising benchtop-scale and kiloton-scale work previously carried out with the assistance of 2003 and 2005 Advanced Detector Research Program grants.

  9. Flow fraction in charged rectangular microchannel to optimally design hydrodynamic filtration chip for cell sorting

    Science.gov (United States)

    Chun, Myung-Suk; Jeong, Sohyun; Kim, Jae Hun; Lee, Tae Seok

    2015-11-01

    Among the passive separations, hydrodynamic filtration (HDF) can perform the fractionation of cells or particles by selective extraction of streamlines controlled by the flow fraction at each branch. Only the stream near the sidewall enters the branches as the focusing, with the amount of fluid leaving the main channel being determined by the flow distribution related to the hydraulic flow resistances. Its understanding is important, but in-depth consideration has not been treated until now. The virtual boundary of the fluid layer should be first specified, and the parabolic velocity profile starts to form from the steady state flow with high Péclet numbers. We computed the 3-dimensional flow profile at the rectangular cross-section with any aspect ratios, by considering electrokinetic transport coupled with the Poisson-Boltzmann and Navier-Stokes equations. The chip was designed with the parameters rigorously determined by the complete analysis of laminar flow for flow fraction and complicated networks of main and multi-branched channels for cell sorting into the finite number of subpopulations. For potential applications to the precise sorting, our designed microfluidic chip can be validated by applying model cells consisting of heterogeneous subpopulations. Supported by the KIST Institutional Program (No. 2E25382).

  10. Paper and board mill effluent treatment with the combined biological-coagulation-filtration pilot scale reactor.

    Science.gov (United States)

    Afzal, Muhammad; Shabir, Ghulam; Hussain, Irshad; Khalid, Zafar M

    2008-10-01

    Pilot scale reactor based on combined biological-coagulation-filtration treatments was designed and evaluated for the treatment of effluent from a paper and board mill. Biological treatment by fed batch reactor (FBR) followed by coagulation and sand filtration (SF) resulted in a total COD and BOD reduction of 93% and 96.5%, respectively. A significant reduction in both COD (90%) and BOD (92%) was also observed by sequencing batch reactor (SBR) process followed by coagulation and filtration. Untreated effluent was found to be toxic, whereas the treated effluents by either of the above two processes were found to be non-toxic when exposed to the fish for 72h. The resultant effluent from FBR-coagulation-sand filtration system meets National Environmental Quality Standards (NEQS) of Pakistan and can be discharged into the environment without any risks.

  11. TECHNICAL BASIS DOCUMENT FOR VENTILATION SYSTEM FILTRATION FAILURE LEADING TO AN UNFILTERED RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    KOZLOWSKI, S.D.

    2005-01-06

    This document analyzed three scenarios involving failures of HEPA filtration systems leading to releases from liquid waste tanks. The scenarios are failure due to high temperature (fire), overpressure (filter blowout), and unfiltered release due to filter failure, improper installation. etc.

  12. Fish mouths as engineering structures for vortical cross-step filtration

    National Research Council Canada - National Science Library

    Sanderson, S Laurie; Roberts, Erin; Lineburg, Jillian; Brooks, Hannah

    2016-01-01

    Suspension-feeding fishes such as goldfish and whale sharks retain prey without clogging their oral filters, whereas clogging is a major expense in industrial crossflow filtration of beer, dairy foods...

  13. [Comparative study on four membrane modules in membrane filtration process of Huanglian Jiedu decoction].

    Science.gov (United States)

    Liu, Hong-Bo; Li, Bo; Guo, Li-Wei; Xiao, Wei

    2013-02-01

    To compare the membrane filtration process of four membrane modules namely, FMX rotating disk flat membrane module, hollow fiber membrane module, tubular membrane module and filter cup membrane module, with traditional Chinese medicine compound Huanglian Jiedu decoction as the experimental subject. Under the same experimental operating conditions, the four membrane modules in membrane filtration process of Huanglian Jiedu decoction were compared in terms flux, resistance distribution, transmittance of index components and membrane fouling. Three membrane modules in the dynamic filtration form--FMX rotating disk flat membrane module, hollow fiber membrane module and tubular membrane module had more advantages than filter cup membrane module in the static dead-end filtration form in terms of permeate flux, transmittance of index components and membrane fouling. However, FMX membrane module that made the fluid in a strong vortex status had better performance than hollow fiber membrane and tubular membrane module in permeate flux and membrane fouling.

  14. Effects of dilute-acid pretreatment conditions on filtration performance of corn stover hydrolyzate.

    Science.gov (United States)

    Sievers, David A; Kuhn, Erik M; Tucker, Melvin P; McMillan, James D

    2017-11-01

    The reaction conditions used during dilute-acid pretreatment of lignocellulosic biomass control the carbohydrate digestion yield and also hydrolyzate properties. Depending on the conversion route of interest, solid-liquid separation (SLS) may be required to split the hemicellulose-rich liquor from the cellulose-rich insoluble solids, and slurry properties are important for SLS. Corn stover was pretreated at different reaction conditions and the slurries were assessed for conversion yield and filtration performance. Increasing pretreatment temperature reduced the solids mean particle size and resulted in slower slurry filtration rates when vacuum filtered or pressure filtered. Corn stover pretreated at 165°C for 10min and with 1% H2SO4 exhibited the highest xylose yield and best filtration performance with a no-wash filtration rate of 80kg/hm2 and cake permeability of 15x10-15. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Evaluation of membrane filtration system using The “Pore Diffusion” for eliminating viruses

    Science.gov (United States)

    HASHIMOTO-GOTOH, Akira; MATSUKI, Takahiro; MIYAZAWA, Takayuki

    2015-01-01

    Here, we report a first study of virus removal by a novel membrane filtration system, named the “Pore Diffusion”. The “Pore Diffusion” manipulated the direction of circulating flow from vertical to parallel to the membrane, thereby achieved to alter the trans-membrane pressure as low as possible. We compared the viral activity between before and after filtration by both infectivity assay and real-time reverse transcription-PCR. Among 4 “Pore Diffusion” modules tested, the big module with average pore size of 80 nm showed the highest log reduction value of viral activity. Our study shows the possibility of “The Pore Diffusion” to filtrate viruses from bioproducts without increasing the trans-membrane pressure, so that the filtration process can be carried out effectively and economically. PMID:25715959

  16. Needleless electro-spun nanofibers used for filtration of small particles

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    2013-08-01

    Full Text Available A composite aerosol filter media was prepared by depositing nanofibers on the non-woven fabrics substrate using needleless electrospinning technique. The polyvinyl alcohol nanofibers with mean diameters of ca. 100 nm were used as top layers. The filtration performance was evaluated by measuring the filtration of sodium chloride nanoparticles (75±20 nm through the filters. It was found that the filtration efficiency of the composite filter media for nanoparticles was increased along with the thickness of nanofibers mats which was controlled by the collection time during the electrospinning. The multi-layer arrangement for fabrication of the composite filter can achieve high filtration efficiency (up to 99.95% which was comparable to commercial high efficiency particulate air filters but with higher quality factor and less mass.

  17. Uncertainty and Sensitivity Analysis of Filtration Models for Non-Fickian transport and Hyperexponential deposition

    DEFF Research Database (Denmark)

    Yuan, Hao; Sin, Gürkan

    2011-01-01

    filtration coefficients and the CTRW equation expressed in Laplace space, are selected to simulate eight experiments. These experiments involve both porous media and colloid-medium interactions of different heterogeneity degrees. The uncertainty of elliptic equation predictions with distributed filtration...... media and the colloid-medium interactions of higher heterogeneity. The parameters for the distribution of filtration coefficients could not be uniquely identified due to strong correlations. In the cases of heterogeneous colloid-medium interactions where hyper-exponential deposition is observed......Uncertainty and sensitivity analyses are carried out to investigate the predictive accuracy of the filtration models for describing non-Fickian transport and hyperexponential deposition. Five different modeling approaches, involving the elliptic equation with different types of distributed...

  18. Allelopathic effects of diatom filtrates on the toxic benthic dinoflagellate Ostreopsis cf. ovata.

    Science.gov (United States)

    Pichierri, Salvatore; Accoroni, Stefano; Pezzolesi, Laura; Guerrini, Franca; Romagnoli, Tiziana; Pistocchi, Rossella; Totti, Cecilia

    2017-10-01

    Ostreopsis blooms regularly occur in many Mediterranean coastal areas in late summer-autumn. In the northern Adriatic Sea, Ostreopsis blooms affect diatom-dominated microphytobenthic communities. In this study, the effects of the filtrates of some diatom species, both benthic (Tabularia affinis, Proschkinia complanatoides and Navicula sp.) and planktonic (Thalassiosira sp. and Skeletonema marinoi) on cell morphology, cytological features and growth of O. cf. ovata were investigated. Our results showed a marked decrease of O. cf. ovata growth when cells were exposed to all diatom filtrates tested. The highest inhibitions were observed for exposures to P. complanatoides and Navicula sp. filtrates (92.5% and 80%, respectively) and increased with the age of diatom culture. Moreover, a clear DNA degradation and abnormal forms of O. cf. ovata cells (83.8% of the total) were found at the highest concentrations using Navicula sp. filtrate after 10 days of the inoculum. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Towards supported bolaamphiphile membranes for water filtration: Roles of lipid and substrate

    NARCIS (Netherlands)

    Kaufman, Y.; Grinberg, S.; Linder, C..; Heldman, E.; Gilron, J.; Shen, Yue-xiao; Kumar, M.; Lammertink, Rob G.H.; Freger, V.

    2014-01-01

    Supported biomimetic membranes hold potential for applications such as biosensors and water purification by filtration. The current paper reports on the preparation of a supported bolaamphiphile membrane on two polymeric nanofiltration membranes: NF-270 made of polyamide with carboxylic surface

  20. Effluent treatment by multi-media filtration, microfiltration and ultrafiltration: results of a pilot investigation at WWTP Hoek van Holland.

    Science.gov (United States)

    te Poele, S; Menkveld, W; Boom, J; van Bragt, W

    2005-01-01

    Upgrading of wastewater treatment plant (WWTP) effluent as a part of the Dutch governmental policy to close the water cycle has increasing interest now. The Water Board Hoogheemraadschap van Delfland together with the project team of Witteveen + Bos Consulting Engineers, Delft University of Technology and Rossmark water treatment investigated the reuse possibilities of WWTP effluent in the region of Delfland. Therefore pilot research was carried out at WWTP Hoek van Holland applying different filtration techniques: multi-media filtration, micro- and ultrafiltration. The results show stable process performances of the different filtration techniques when proper pre-treatment was applied. For microfiltration the filtration characteristics were strongly influenced by particles which were not retained in the multi-media filter. For ultrafiltration the filtration characteristics were strongly influenced by organic components filtrates. However WWTP effluent or floc filtrate could be applied directly as water for the washing of sea-sand.