Sterlitech Blog

Your source for new information on filtration equipment applications and processes.

  1. Vactrap™: A Novel Vacuum Trap Solution

    Vactrap™: A Novel Vacuum Trap Solution

    Help keep your lab equipment and personnel safe by upgrading to the innovative Vactrap™ system. This product is a new and improved take on vacuum traps. The Vactrap™ protects vacuum pumps from contamination using vacuum-stable bottles and a sterilizing in-line vent filter.


    Many existing vacuum trap assemblies include multiple glass flasks and tubing held in place by ring stands. This durable plastic system can easily replace traditional vacuum traps in the lab, freeing up valuable bench space and preventing hazards. Specific applications include supernatant removal, media/culture aspiration, and chemical/solvent separation.




    As a ready-to-use product, the Vactrap™ system includes chemical-resistant 2L and 1L HDPE bottles that exceed CDC recommendations for vacuuming biohazardous materials. Autoclavable polypropylene bottles are also available for use in this system. Each bottle features a VersaCap for tangle-free opening. The associated tubing is also included, with a pinch clamp to modulate use and a 0.2 micron PTFE vent filter shielding the vacuum line from aerosolized bacteria. These components are nested in a CDC-compliant secondary containment bin to create a compact yet highly sturdy assembly, allowing for robust filtration with no fear of pump damage.


    Read more about how the Vactrap™ can improve your lab work and safety.

  2. Explore new applications with your stirred cell

    Explore new applications with your stirred cell

    Sterlitech now offers our full range of microfiltration and ultrafiltration flat sheet membranes cut in disk sizes compatible with our polymeric stirred cells. These include membranes from SUEZ (GE Osmonics), Synder Filtration, and Microdyn Nadir. These discs are available in 25, 43, 62, 76, 90, and 150 mm diameters.


    Disk filters in combination with the low-pressure polymeric stirred cells can be used as a fast and easy method for a wide variety of filtration/separation applications, such as performing filtration of fluids with heavy particle loads or concentrating biological components and macrosolutes (DNA, RNA, protein, etc.).  Other examples of applications for low-pressure filtration include cell harvesting, diafiltration, lysate clarification, and suspended solids removal. Additionally, mechanical stirring mechanism minimizes concentration polarization and membrane fouling while operating at high permeate flow rates and recovery. 


    Our technical sales representatives are happy to aid with membrane selection and process development - please consult with us about your stirred cell application projects!

  3. Hastelloy Cells and Systems

    Hastelloy Cells and Systems

    Sterlitech has seen a rising trend in the need for highly resistant membrane filtration systems from researchers.  In response to this trend, HastelloyTM (C-276)1 versions of bench-top stirred cells,  cross flow and forward osmosis test cells have been developed and are now available for the Stirred cells,  Developer, Explorer, and Innovator product families.


    HastelloyTM (C-276) is a steel superalloy containing nickel, chromium, molybdenum, and tungsten. It has outstanding resistance to corrosion, pitting and cracking when exposed to a wide range of aggressive chemicals and corrosive solutions: such as concentrated halide salt solutions, strong acids, and oxidizing acids.


    How about highly resistant system components and parts?


    To provide ultimate support, Sterlitech now offers high pressure feed flow pumps and pressure gauges with HastelloyTM (C-276) wetted parts. We also supply fittings, tubing and valves made of HastelloyTM (C-276). Users can now assemble membrane systems fully configured with highly resistant components and parts.


    How about a pre-assembled highly resistant filtration systems (Skids)?


    Fully assembled (and tested) analog and digital membrane filtration systems (Skids) can now be configured with highly resistant HastelloyTM (C-276) components, parts and cells! Please contact us to learn more about these products and custom built systems.


    References:
    [1] http://www.haynesintl.com/alloys/alloy-portfolio_/Corrosion-resistant-Alloys/HASTELLOY-C-276-Alloy/principal-features.aspx

  4. Discoveries in membrane filtration technology using graphene oxides

    Discoveries in membrane filtration technology using graphene oxides

    Graphene oxide (GO) has made its way to more than 500 peer-reviewed journal articles in 2017, demonstrating a variety of membrane technology applications.  Out of the 500 papers, about 80 have investigated the use of graphene oxide for filtration applications (Figure 1). Research on graphene oxide has been a rapidly growing field since 2012, when Nair et al. first demonstrated that GO membrane allows unimpeded permeation of water while blocking all other compounds in the vapor phase.1




    Graphene oxide membranes have been extensively investigated for water desalination, oil-water separation, gas separation and pervaporation applications. This material is also being developed into commercial membrane products. G2O is a UK-based company with a patent to utilize graphene oxide membranes to separate oil from water. This technology is applied in the oil industry to create fresh water from seawater. G2O is currently working with a number of industry and innovation partners to scale up and bring this technology to market.2


    Why graphene oxide?


    Due to its high mechanical strength and chemical inertness, nearly frictionless surface, and cost-effective production in solution, GO plays strongly as a nanomaterial for the fabrication of novel separation membranes. Membranes made from graphene oxide have been shown to be capable of sieving out small nanoparticles, organic molecules, and even large salts.3


    In comparison with other available membrane materials, the ease in making atomically-thin GO layers with uniform pore size distribution provides an edge over other membrane materials for practical applications. The resulting graphene oxide membrane, being much thinner than existing polymeric membranes, could achieve a much higher permeate flow with lower energy requirements.


    Where is research headed for graphene oxide membranes?


    One of the obstacles preventing widespread application of graphene oxide membranes for water desalination is that the membranes swell when immersed in water; this enlargement of the pores enables small salts such as sodium chloride to flow through.  Low durability and stability of graphene oxide membranes is another challenge to overcome in various applications.


    To address these issues, current research is developing means of controlling membrane channel size and improving the durability of the membrane.4 Additionally, a deep understanding of water and ion transport through graphene oxide membranes is required to achieve appropriate and tunable membrane performance when being applied to desalination, pervaporation and other fields.


    References:
    [1] J. Abraham, K.S. Vasu, Ch. D.Williams, K.Gopinadhan, Y.Su, Ch. T.Cherian,...R.R. Nair, “Tunable sieving of ions using graphene oxide membranes”, Nature Nanotechnology, 2017, 12, pp 546–550.
    [2] http://g2o.co/
    [3] M.Fathizadeh, W.L. Xu, F.Zhou, Y.Yoon, “Graphene Oxide: A Novel 2-Dimensional Material in Membrane Separation for Water Purification”, Advanced Materials Interfaces, 2017.
    [4] W.L. Xu, Ch. Fang, F.Zhou, Z.Song,† Q.Liu, R.Qiao and M.Yu, “Self-Assembly: A Facile Way of Forming Ultrathin, High-Performance Graphene Oxide Membranes for Water Purification”, Nano Letters, 2017.

  5. Cape Town Avoids Day Zero

    Cape Town Avoids Day Zero

    After months of living under the looming threat of “Day Zero”, Cape Town has tentatively pushed back the deadline of extreme water crisis for the remainder of the year. Day Zero, which had originally been scheduled for April 22, reflects the date when water levels in the city's major dams reaches 13.5% of their capacity. If this day arrived, taps would be shut off and Cape Town residents would need to stand in line to pick up their 25-liter daily ration of water.1 For perspective, this equivalent to the amount of water consumed in a four-minute shower.2


    Drought-driven water shortages are a worldwide crisis. The cities at highest risk to run out of water include Jakarta (where the city is sinking from illegal groundwater extraction as sea levels around it rise), Mexico City (where taps are already turned off for many city citizens for parts of the day), Tokyo, London, and Miami.3 In California, almost 50% of the state is currently experiencing moderate drought.4


    Cape Town is South Africa’s second largest city, with about 3.75 million metropolitan inhabitants.5 Since 2015, the city has been experiencing its worst drought in a century, the impact of which is compounded by continued population growth.1 As local dams continue to dry up, the city has attempted to conserve water by reducing consumption. The government has shut off unnecessary public water and invested in the construction of desalination plants and waterways from nearby sources. Individuals are recommended to limit their toilet flushing and opt for 90 second showers. In a city with a strong tourist economy, restaurants often no longer offer free water and bathroom sinks have been foregone for hand sanitizer.


    Water consumption has historically been over 200 liters per capita in Cape Town, but government and community efforts have successfully reduced this to about 120 liters.6 In the US, average water consumption per capita is 300-350 liter/day.7 Cape Town may have delayed this crisis for now, but the issue poses a question to other drought-prone cities; how will they prepare for water shortages in a world with a changing climate?


    Long term solutions to global water security will involve rainwater harvesting, wetlands conservation, and reshaping land use/agricultural practices.8 Responsible groundwater pumping and desalination of seawater can contribute to maintaining future sources of potable water. Individuals can also make an appreciable impact by reusing gray water for non-potable applications – reuse for gardening, toilet flushing, or laundry can reduce indoor water demand by 36%.9 By increasing awareness and individual conservation, improving infrastructure, and investing in technology, we can ensure access to water for future generations.


    References:
    [1] https://www.cnn.com/2018/02/01/africa/cape-town-water-crisis-intl/index.html
    [2] https://news.nationalgeographic.com/2018/02/cape-town-running-out-of-water-drought-taps-shutoff-other-cities
    [3] http://www.bbc.com/news/world-42982959
    [4] http://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?CA
    [5] http://www.statssa.gov.za/?page_id=1021&id=city-of-cape-town-municipality
    [6] https://matadornetwork.com/read/cape-town-may-averted-major-water-crisis-history
    [7] https://water.usgs.gov/edu/qa-home-percapita.html
    [8] https://globalnews.ca/news/4092185/water-shortage-un-2050
    [9] http://thefutureofthings.com/11039-can-cities-protect-drought

  6. Polycarbonate Membrane Filters for the Seq-Well Platform

    Polycarbonate Membrane Filters for the Seq-Well Platform

    The Seq-Well protocol uses PCTE membranes in an innovative platform for rapid single-cell transcriptomics. This powerful tool in the world of clinical discovery offers a precise snapshot of cellular behavior.


    As the product of a joint research venture between the Shalek and Love groups at MIT, this portable device combines single-cell sequencing with microfluidics technology. The system enables researchers to study RNA transcripts present in numerous individual cells at a given point in time. Thousands of cells undergo parallel RNA sequencing for thousands of genes, yielding large sets of data that indicate patterns in gene expression. For example, data collected by the developers of this technology has been used to implicate basal cellular heterogeneity in individual tuberculosis responses.1


    In the Seq-Well system, a nanowell array captures single cells for sequencing. These wells are protected by a semipermeable membrane, which allows for lysis chemicals to pass through but retains the subsequently freed RNA for collection on barcoded beads. The freed RNA is then sequenced using next-generation methods.


    The protocol utilizes Sterlitech’s 0.01 micron pore size polycarbonate track-etch (PCTE) membrane filters; the 62 x 22 mm rectangular filters undergo plasma treatment and additional modifications to create the semipermeable membrane necessary for RNA collection. Our goal is to equip researchers with the tools they need to push the boundaries of science and technology.


    References:
    [1] Gierahn, T. et al. Seq-Well: portable, low-cost RNA sequencing of single cells at high throughput. Nature Methods 14, 395-398 (2017).

  7. Sterlitech Now Offers Rosin Pressing Papers

    Sterlitech Now Offers Rosin Pressing Papers

    Rosin extraction is a popular, solvent-free method of concentrating cannabis. In this process, heat and pressure are applied to plant material (e.g. flowers or kief) to yield a purified resinous product. It’s fast, simple, and eliminates the concern of residual solvents.


    Sterlitech’s rosin pressing papers can be used as a replacement for parchment paper, which is often used to collect rosin during the extraction process. These papers come in pre-cut sizes (4” or 6” squares) and offer superior quality to parchment paper you might find at the grocery store. Sterlitech's rosin pressing papers are composed of analytical-grade cellulosic paper. The smooth, calendared surface resists moisture absorption and tearing.


    Rosin extraction can be optimized by using trichome-rich strains, cold-pressing after extraction, and utilizing high quality paper for collection. Enhance your rosin extraction with the high uniformity and value of Sterlitech pressing papers.

  8. Sterlitech expands its flat sheet membrane selection with new membranes from Microdyn-Nadir

    Sterlitech expands its flat sheet membrane selection with new membranes from Microdyn-Nadir

    Sterlitech is launching new flat sheet membranes; TriSep MF01 and TriSep UB70.


    The MF01 microfiltration membrane has various applications, especially for the food and dairy industries. Specific applications include clarification, fat removal, product concentration in sweeteners, whey processing, and fermentation broth filtration. It is also used industrially for concentration of macromolecules and large organic solutes.


    For ultrafiltration, the UB70 membrane is designed for use in food & beverage, dairy, and wastewater treatment applications. This material is also suitable for treating produced water, MBR peak flow management, tertiary wastewater, and phosphorous removal.



     


     


     


     


     


     


    *GFD: Gallons per square foot membrane active area per day


    These new additions are available in large sheets or precut coupons for use in the Sepa CF or CF042 cells and most stirred cells. Custom membrane sizes are also available upon request.

  9. Discontinued SG Series Flat Sheet Membranes from SUEZ (GE Osmonics)

    Discontinued SG Series Flat Sheet Membranes from SUEZ (GE Osmonics)

    Sterlitech would like to notify our customers that SG flat sheet membranes from SUEZ (GE Osmonics) are being discontinued by the manufacturer. Limited quantities of SG flat sheet membranes in various sizes are currently available.


    Product: SG
    Manufacturer: SUEZ (GE Osmonics)
    Type: Chlorine Resistant
    pH Range: 1-11
    MWCO: N/A
    Polymer: TFC


    Our complete selection of membranes for reverse osmosis can be viewed on the flat sheet membrane page. 


    For more information about available RO membranes, or if you would like product selection assistance for your specific application, please contact us at 1-877-544-4420 or sales@sterlitech.com.

  10. Silver Membranes in Monitoring Respirable Crystalline Silica

    Silver Membranes in Monitoring Respirable Crystalline Silica

    Crystalline silica, most commonly found in the form of quartz, is a basic component of the earth; it’s found in soil, sand granite, and other minerals. During many industrial processes, crystalline silica is released as particles that are 100 times smaller than beach sand.1 Due to their size, these mineral particles cannot easily be cleared by human lungs. Instead, they persist in the respiratory system and form scar tissue, contributing to serious health problems for those experiencing prolonged exposure. The associated silicosis and other forms of cancer are a threat to workers in mining, construction, and other industrial trades.2


    There is a global awareness of this seriousness of this issue, and the World Health Organization has published assessment documents detailing the negative health effects of exposure. Here in the US, the Occupational Safety and Health Administration (OSHA)  released a Final Rule on Occupational Exposure to Respirable Crystalline Silica, to provide guidance for the safety of industrial workers.3 The ruling published in March 2016 puts the responsibility on companies to create a low-risk environment, with enforcement in the form of fines (potentially over $12,000 per day) going into effect for some industries starting in September 2017.3 Beyond recommending proper personal protective equipment, ventilation systems, and replacement of silica when safer materials can be used, this ruling establishes a permissible exposure limit (PEL) at 50 μg/m3. This means that only 1/5th of the previously allowed PEL is now considered safe in the workplace.2


    To monitor levels of crystalline silica, employers can take routine samples and have them analyzed in a lab. A portable sampler is used to collect air from the worker’s respirable area during a full shift. The dust captured on the filter is then analyzed using a standard method, such as NIOSH 7500.4 In this method, the filter is then dissolved and redeposited on a 0.45 micron silver membrane for measurement using x-ray diffraction. Silver membranes have become the standard for x-ray diffraction analysis due to their high sample-load capacity and characteristically low background noise during analysis.


    The results of these analyses help employers understand whether they need to be taking more action to protect their workers. OSHA estimates that the steps advised in their ruling will save 600 lives and prevent 900 cases of silicosis every year.5 For now, companies in regulated industries are developing control plans and training workers to ensure compliance with the new rules. It remains to be seen what the full impact of enforcement will mean for their employees and their business.




    References:
    [1] Dangers of Crystalline Silica | Taylor Made Diagnostics. Taylormadediagnosticscom. 2018.
    [2] Spafford A. OSHA Silica Dust Permissible Exposure Limit 2016 Update. Pro Tool Reviews. 2018.
    [3] Occupational Exposure to Respirable Crystalline Silica. Federal Register. 2018.
    [4] Safety and Health Topics. Respirable Crystalline Silica - Sampling and Analysis. Occupational Safety and Health Administration. Oshagov. 2018.
    [5] Everything You Need to Know About OSHA's Respirable Crystalline Silica Final Rule. Occupational Health & Safety. Occupational Health & Safety. 2018.

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