Ultrafiltration appears as the most efficient barrier for suspended solids, bacteria, virus, endotoxins, and other pathogens, for the production of high purity - low SDI water. It’s used as pretreatment for surface water, sea water and biologically treated effluents, and prior to membrane demineralization systems, such as nanofiltration and reverse osmosis.

Unitek®, authorized OEM to design, construct and operate ultrafiltration systems with X-Flow membranes, counts with know-how and experience in a wide range of applications.


  • Stainless Steel Skids
  • 50 - 200 microns self-cleaning filters.
  • Optimum hydraulic design.
  • Low incrustation level.
  • Totally automatic Backwash and CEB.
  • High mechanical resistance of the hollow-fibers.
  • Inside/out filtration.
  • Automatic Integrity Test of the membrane.
  • Totally automatic chemical dosing.
  • PLC controlled.


  • Its compact design reduces footprint.
  • 50% less area compared to conventional systems (chemical dose, static mixer, flocculation decanter, multimedia filter)
  • Lower investment.
  • No use of coagulants.
  • Low operating pressures (< 2 bar).
  • Lower chemical consumption.
  • Efficient pathogen removal.
  • It extends life of reverse osmosis membranes, when used as pretreatment for high SDI waters.


  • Constant water quality regardless of the TSS on feed water (turbidity < 0,1 NTU).
  • Efficient pathogen removal.
  • 4-Log (99,99%) viral reduction.
  • 6-Log (99,9999%) bacteria reduction.
  • Arsenic removal by addition of coagulants.
  • Organic matter reduction between 50 and 90%.

Membranes are made of Polyethersulfone (PES) and have a great permeability. Norit not only positions as a leader brand on the market, but has managed to combine excellent permeability with high resistance of the membranes.

Depending on the Total Suspended Solids Concentration, the following membranes can be selected:

Membrane Model

TSS (mg/l)

X-Flow XIGA™

< 50

X-Flow AquaFlex™ Low-Solids

50 – 200

X-Flow AquaFlex™ High-Solids

200 - 1,000

X-Flow CrossFlow™

1,000 - 40,000


  • Uses by-pass tubes to improve hydraulics of the membrane.
  • Fewer amounts of valves and connections per square meter of membrane surface area.
  • Lower footprint compared to other alternatives of installation for the same water production.
  • Reduction of the fouling rate due to the exclusive hydraulic distribution patented by X-Flow.
  • Lower energy consumption associated to a lower pressure drop (fewer accessories installed).
  • Standardization of spare-parts since it uses the same pressure vessels as reverse osmosis.

The concept of a horizontal multi-element configuration, imitates the reverse osmosis design, with four 1.5-meter elements installed inside a 6-meter pressure vessel, allowing for a more efficient use of the installation site.