World-wide the demand for fresh water grows, while the availability decreases. Emerging technologies can offer an important contribution to future water treatment. It is fully recognised nowadays that membrane filtration has conquered a mature place in the production of drinking and industrial water. Due to the development of high-flux low-pressure ultrafiltration capillaries, the introduction of  the 8” module design, and the development of the energy-efficient dead-end filtration a flexible unit operation is available for relative small water treatment plants in remote areas till large scale water factories.
 

The Norit AquaFlex™ system is an excellent system for the treatment of water with a higher content of suspended solids being a perfect complement to the Norit XIGA™ system. The vertical placed membrane modules are also operated in semi dead-end mode and cleaned by the patented AirFlush® procedure. The combination of backwashing with air enhanced forward flushing destabilises and washes out the cake-layer formed during the dead-end filtration very effectively.
 

Norit AquaFlex™ systems are used for:

• LowSolids: suspended solids content up to 200 mg/l;
• HighSolids: suspended solids content up to 1,000 mg/l.

Main references are found in:

• LowSolids: small scale (remote) water supply systems;
• HighSolids: recovery of (sandfilter) backwash water.
   
  
  
  
  
  

The Norit AquaFlex™ system uses X-Flow modules:

• LowSolids: 1.5 m long 8” PVC modules with CAPFIL 0.8 or 1.5 mm ultrafiltration membranes;
• HighSolids:3 m long 8” PVC modules with COMPACT 5.2 mm ultrafiltration membranes;
• with permanent hydrophilic low-fouling ultrafiltration membranes.

In a semi dead-end system all the feed supplied to the systems leaves as permeate. The capacity is controlled by adjusting the transmembrane pressure. At regular time intervals the system is subjected to an AirFlush® with a back-wash to remove the retained particles. Adsorbed substances are removed by an "in situ" chemically enhanced backwash.
 

Norit AquaFlex™ systems are available as standardised, modular plug-and-play skids. The modules are placed vertically resulting in very reliable and compact installations.
If desired customer-built systems can be supplied.