Ultrafiltration (UF) is a type of membrane filtration wherein forces such as pressure or concentration gradients proceed through a semipermeable membrane to isolation. For so-called retentate, suspended solids and high molecular weight solutes are retained, while water, including low molecular-weight solutes, flow via the permeate (filtrate) membrane.
Different type of modules can be used for ultrafiltration processes depending on the shape and material of the membrane. Commercial designs that are available for ultrafiltration modules differ depending on the hydrodynamic and economic constraints and the mechanical stability of the device under operating pressure. The ultrafiltration modules used in the industry are -
- Tubular modules.
- Hollow fiber.
- Spiral-wound modules.
- Plate and flame.
The membrane used for ultrafiltration is characterized by the molecular weight cut-off (MWCO). Ultrafiltration is used in crossflow mode or in dead-end mode.
Ultrafiltration membranes are relatively late entrants in potable water filtration methodologies. They must contend with established disinfection methodologies as well as with new aggressive disinfection process substitutes such as ultraviolet-based disinfection. Within the membrane fraternity itself, ultrafiltration stakeholders have to contend with nano- and microfiltration variants.
What also hampers their acceptance is the inability to deliver end-to-end solutions on a stand-alone basis. The abovementioned challenges will drag the growth rate of ultrafiltration technology adoption to the lowest rate among peer technologies. On the positive side, however, ultrafiltration technologies stand to gain from the increased focus on reverse osmosis methodologies. These membranes can act as effective pre-filters to the feed supplied to reverse osmosis plants. While reverse osmosis is thought to be investment intensive, the alarming water availability situation in many parts of the world has forced stakeholders to explore this option with greater vigor. Reverse osmosis cannibalizes the pure ultrafiltration market to some extent. Ultrafiltration membrane stakeholders must channel their efforts to maximize the benefits associated by partnering with reverse osmosis stakeholders.
Hemodialysis will continue to be the largest application for ultrafiltration membranes. The fundamental reason for the extraordinary use of this application is a near perfect fit between the demands of hemodialysis process and the deliverables promised by ultrafiltration membrane technologies. Use cases associated with this End-Use have been well-established. While it is a mature market in terms of the adoption cycle of ultrafiltration technologies, it is an expanding market when looked upon in the general context of growing incidences of lifestyle-induced ailments. Kidney treatments continue to account for a substantial proportion of healthcare resources that need to be devoted to managing endstage renal diseases that are triggered by a multitude of issues common with today’s lifestyles. As larger segments of populations in emerging economies pull themselves out of poverty, the world is staring at a veritable explosion in the numbers of senior citizens. The vibrancy in the underlying market itself will act as a strong antidote to the growth mitigating factors that characterize mature markets. Consequently, the adoption of ultrafiltration membranes in the hemodialysis End-Use will continue to determine the growth rate of the larger ultrafiltration market over the next five years.