The Need for Specialty Membranes Expands
Membranes are being used to treat more challenging feed waters as the capability limits of spiral-wound elements extend. More and more applications are emerging that require specialty spiral-wound membrane elements capable of handling high temperatures, extreme cleaning conditions, or high pressure. These challenges and others are covered in the webinar titled Solutions for Difficult-to-Treat Feed Waters available now.
Different specialty spiral-wound membrane elements available from MICRODYN-NADIR can be used to treat these difficult feed waters. Learn more by watching the webinar!
In the Links section, the slide-share from the webinar is available for download. Additional information is available in the paper Innovative Spiral-Wound Membrane Elements for High Temperature Desalination Applications.
Applications for Specialty Membranes
High-Fouling RO Feed Water
Membrane fouling occurs when particulates are deposited on the membrane surface. High-fouling RO feed water leads to reduced permeate flow, frequent membrane cleanings, and short membrane life.
Solution: Low-Fouling RO Membrane
TRISEP® X-20™ Low-Fouling RO is an excellent solution when treating high-fouling wastewater streams, surface waters with minimal pretreatment, or other high fouling applications. The X-20 membrane can handle more organics in the feed water and help companies better utilize the surface water stream.
High Temperature Feed Streams
Typical spiral-wound elements are limited to 45ºC (113ºF) due to their materials of construction. High temperature operation causes material deformation. However, processes in laundry wastewater, boiler blowdown, and produced water applications deal with high-temperature streams. There is a high cost associated with cooling the streams to standard element limits.
Solution: High Temperature Membrane Elements
Avoid wasting money and energy to cool the feed by using high temperature RO elements (like TurboClean® HT RO). TurboClean HT specialty elements use durable materials of construction and have a maximum operating temperature of 80ºC (176ºF). We also offer a line of warm temperature elements capable of handling 60ºC continuously called TurboClean® WT RO.
Chemical Sanitizer Limits
Some processes limit the use of chlorine, a chemical used for sanitation in many membrane systems. This limit could be due to application-specific requirements (regulatory), membrane chemistry limits, or health and safety. But elimination of microbes is still required.
Solution: Heat-Sanitizable Elements
Heat-sanitizable elements are especially important in pharmaceutical and medical applications, including water for dialysis and water for IVs because these applications ban foreign chemicals in the stream. To sanitize the elements, hot water is used, which requires heat-sanitizable elements like TurboClean® Heat Sanitizable Elements.
Heat-sanitizable elements deliver high purity permeate while also withstanding hot water sanitization up to 85ºC (185ºF), which eliminates the need for chemical sanitizers (e.g. chlorine).
High TDS Feeds
High TDS feed streams require high-pressure operation. Typical spiral-wound elements are limited to 41 bar (600 psi); high-pressure operation with standard elements causes material deformation. Applications examples for high TDS steams are MLD and ZLD, as well as seawater RO and NF.
Solution: High Pressure Membrane Elements
Using specialty membranes created especially for high-pressure situations is the ideal solution. TRISEP® High Pressure elements have a maximum operation pressure of 83 bar (1,200 psi) while TRISEP Ultra-High Pressure elements can go up to 120 bar (1,740 psi) to overcome high osmotic pressure. These elements are available with RO or NF membrane for monovalent/divalent separation and use durable materials of construction.
Chlorine Required to Limit Bacterial Growth
Standard polyamide membranes are limited to <0.1 ppm chlorine in feed stream. In some applications, residual chlorine is required to prevent bacterial growth. Therefore, a chlorine-tolerant membrane is required. Those applications include beverage production and natural organic matter (NOM) removal, among others.
Solution: Cellulose Acetate Membrane Elements
Cellulose acetate (CA) membrane can handle continuous residual chlorine up to 1 ppm continuous and up to 30 ppm for short-term cleaning. In beverage production, TurboClean® Bev CA elements offer a patented hard-shell exterior for durability and increased productivity.
MICRODYN-NADIR is one of the only suppliers of cellulose acetate spiral elements.
