Page 9 - Filtration Resources
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March 11, 2020Why Perform a Bubble Point Test? In the bubble point test, pore size rating is determined by measuring the lowest air pressure needed to overcome the surface tension between the wetting liquid and the membrane pores in a fully wetted membrane. This pressure level, known as the bubble point, is signaled by the first appearance of a steady stream of bubbles observed from a special disc filter holder through the downstream side of the membrane filter. The measured bubble point is then correlated to the membrane pore size diameter.
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January 10, 2020Membrane Distillation (MD) is a relatively new and promising separation technology that is an alternative to more energy intensive methods such as reverse osmosis or distillation. MD is a thermally driven process where only vapor molecules transfer through a hydrophobic (water repellent), microporous membrane.
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December 09, 2019We like to remind our customers to be careful when feeding chemical solutions into their Membrane Filtration Systems. Ensuring that the chemical solutions are compatible with the wetted parts of these filtration systems or membranes will help you achieve consistent results and lengthen the service life of your systems to support future experiments.
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November 06, 2019A common question users of disk, syringe, and capsule filters ask is: How long will my filter last? Or, put another way: How much fluid can I expect to pass through my filter before it clogs? The answer to this question will help users select appropriately sized filters.
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September 11, 2019Pore size rating is among the key selection criteria for membrane filters as it indicates the extent of particle size (including microorganisms) that can effectively be retained in a filtration application. With its importance, manufacturers are compelled to provide pore size ratings as accurately as possible.
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July 08, 2019With around 220 million infected in 2017, schistosomiasis (“snail fever”) remains a major public health concern, especially in the endemic regions of Africa which account for about 90% of cases worldwide [1]. Schistosomiasis is caused by tiny, parasitic flatworms carried and released by certain species of freshwater snails. Infection occurs when individuals come into contact with contaminated water. The disease burdens low-income communities in developing regions with poor access to safe sources of water and sanitary facilities.
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June 04, 2019
Did you miss our webinar on microfiltration membranes? The webinar recording is now live, click on the video below. Our filtration experts discussed the characteristics and applications for membrane filters2, and answered any questions during the webinar.
What we went over in the webinar:
- Microfiltration membranes
- Concepts and mechanisms of separation
- Membrane characteristics and selection
- Wettability
- Pore size rating
- Q&A
Are you interested to register for future webinars? Now you can click here.
Contact [email protected] for any questions.
References
- Introduction to Microfiltration Membranes - (2019). Retrieved from https://www.youtube.com/watch?v=i5UwU7fjFUk
- Membrane Disc Filters (2019). Retrieved from https://www.sterlitech.com/membrane-disc-filters.html
- Sterlitech Corporation YouTube Channel - (2019). Retrieved from https://www.youtube.com/channel/UClJKohDCP7LmH7CXrt3yysg
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June 04, 2019
The Hydracell pump is a sealless positive displacement pump used to generate cross flow in our filtration systems equipped with cross flow test cells . The sealless design enables it to handle abrasives and particulates; the positive displacement design enables the pump to generate consistent flow rates regardless of the operating pressures up to 1100 psi (76 bar).
To ensure optimal performance of the pump over extended periods, observe the proper operation and conduct regular maintenance. Here are some of our tips for ensuring a reliable Hydracell pump.
Before Starting Up
Check the pump for the following items:
- All pressure control valves in the system are open
- Pump has adequate supply of fluid in the feed tank
- All connections in the pump inlet and outlet are tight
- Oil level is ¾ inch (20 mm) from the top of the fill port
Recommended Operating Condition
Maximum operating temperature: 160 °F (71 °C) (specified on the pump body)
NOTE: A few of our pump units can be operated up
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April 28, 2019
Total Suspended Solids (TSS) measurements quantify particles larger than 2 microns found in a water column. These can include inorganic compounds (gravel, sand, silt) or organics (algae, plankton, and decaying plant or animal matter). TSS contributes to the optical clarity or turbidity of water, but also includes solids that can settle at the bottom of a body of water.
Using standard EPA methods 2540C and 2540D, TSS can be quantified via gravimetric analysis1.2. A water sample is filtered through a pre-weighed glass fiber filter, capturing the solids larger than 2 um. Then, the filter is dried in an oven to remove remaining water and weighed again. The weight difference over the sample volume provides the TSS concentration in mg/L. An interesting technology advancement for TSS testing is offered in the WaterVac Filtration System. This vacuum filtration apparatus features two stainless steel filter holders for improved capacity when testing multiple water samples. And it features
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April 10, 2019
Nobuto Blood Filter strips are an easy and portable method of collecting wildlife samples in the field. Typically used by researchers in diagnosing common bird diseases, they can be utilized in testing wild animals for a whole host of zoonotic pathogens including toxoplasmosis, hantaviruses, measles, plague, and tularemia.1,2 In fact, scientists often collaborate with local hunters and trappers to collect data from their harvests.
Made from high-purity cellulose fibers, Nobuto filter strips are structured for uniform sampling. Each strip holds approximately 0.1 mL of blood or 0.04 mL of serum.
Once blood is applied and the strip has dried, researchers can analyze, store, or mail the samples without refrigeration. Downstream testing for antibodies (i.e. ELISA) is employed to diagnose disease.3 They have proven a valuable tool in surveillance of avian influenza viruses, Newcastle disease virus (NDV), and West Nile virus (WNV) in wild birds. The strips can also be used in environmental
