About Q-SEP®

Ultrafiltration (UF) is a membrane process used to remove suspended solids, colloidal matter, high molecular-weight substances, bacteria and viruses from various feed water sources. UF membranes can achieve a low and consistent silt density index (SDI) and are often used as pretreatment for reverse osmosis using surface water, seawater and biologically treated wastewater as feed source.

Q-SEP UF membranes incorporate high strength hollow fibers which deliver superior performance without the risk of fiber breaks. These UF membranes are made from a hydrophilic polyether sulfone (PES) material with excellent low fouling characteristics and operate under a pressurized inside-out flow configuration for superior performance. Q-SEP modules are manufactured with NSF-PDWEP certification for drinking water application.

Q-SEP Technology

Q-SEP UF fibers and modules are manufactured in a state-of-the-art, environmentally controlled manufacturing facility. In the facility, continuous online monitoring to maintain consistent quality. Turbidity can be reduced to less than 0.05 NTU. Typically, a 6-log removal for bacteria, giardia and cryptosporidium, while a 4-log removal for viruses, can be achieved.

Q-SEP modules contain an advanced UF fiber prepared by an innovative patented cloud point precipitation method. This method ensures a very uniform pore size distribution and high pore density in the membrane. As a result, the product water quality from the Q-SEP modules is significantly better than the quality from conventional UF modules at a very low operating pressure.

The fibers in the Q-SEP module are held firmly in place, which reduces the stress on the fibers even at high flow velocities. Uniform fiber packing limits the pressure drop variation within the module and prevents localized high fouling conditions. The unique end cap sealing design allows for high pressure operation and ease of assembly. The UF modules can be used as dead-end filtration or in cross flow mode. The membranes are available with 0.8 mm ID fibers, suitable for feed water with low turbidity and 1.2 mm ID fibers, suitable to treat water with higher turbidity.

What NSF-PDWEP Certification says about Q-SEP membranes?

NSF has certified the Q-SEP 2008, Q-SEP 4508, Q-SEP 6008, Q-SEP 3412 and Q-SEP 4512 UF modules for Cryptosporidium removal efficiency, using Bacillus endospores as a surrogate following the USEPA Long Term 2 Enhanced Surface Water Treatment Rule product-specific challenge testing framework meets with all applicable requirements of NSF/ ANSI 419. The Qua Group LLC uses a pressure decay test as their manufacturing NDPT for the Q-SEP modules.

Advantages to Q-SEP:


Value to Customer

Patented Cloud Point Precipitation Process

Higher Quality Filtration
Unique manufacturing process results in uniform pore size distribution on membrane surface resulting in consistently lower filtrate SDI.

High Porosity

Lower Capex or Lower Opex
Can be operated at higher flux or lower TMP.

Lower Cleaning frequency

Better Availability
QSEP has superior fouling resistance properties.

Better Mechanical Integrity

QSEP has superior product design and mechanical integrity of components.