Membrane Technologies

Membrane Technologies have several membrane configurations available for Membrane Bioreactor (MBR) applications. Project requirements should drive the decision for membrane selection.

Technologies available for use in MBRs:

Tubular Membranes

The original and most proven type of ultrafiltration is tubular membranes:

Of all membrane types, they are more robust and can be subjected to high pressures in demanding applications.

Out-of-Basin MBR is a configuration where mixed liquor is pumped at high velocity through the tubular membrane module. The high velocity continuously scours the membrane surface and prevents solids from building up. This process produces high flux rates and simple operation. No backwash is required.  Lowest capital cost option because of the high flux rates and simple operation. Out-of-Basin MBRs by Dynatec are designed so that the energy requirements are equal to other types of MBR systems.


Hollow Fiber Membranes

They are constructed of a microporous structure having a dense selective layer on the outside surface. Many fibers must be packed into bundles and potted into tubes to form a membrane module. The surface area of even a few square feet require miles of fibers. Modules must contain no defective or broken fibers, therefore production requires strict quality control.

These membranes can withstand very high pressures from the outside, but are limited on pressure exerted from the inside of the fiber, therefore backwash rates are limited to around twice the normal permeate rate. The feed fluid is applied on the outside of the fibers and the permeate is removed down the fiber bore.

Hollow Fiber membranes are applied in clean water applications and are used in MBRs, but are limited to lower concentrations of solids than the other membrane types.



Flat Plate Membranes

They are constructed of a paper like backing material with a membrane cast on the surface of the paper. The membrane sheet is ultrasonically welded to both sides of a plastic plate. These plates are assembled into a submerged membrane unit and spaced about 1/4″ apart. The permeate passes through the membrane unit from the outside in. Course bubble air is sparged between the plates to prevent solids from building up on the plates and dewatering the membranes.

These membranes used in MBR applications require a biofilm to be attached to the membrane. The membrane is a support structure to the biofilm which actually provides the filtration. Care must be taken to maintain the biofilm on the membranes to prevent failure.



Membrane Technologies


Tubular HiRate™

Tubular Dynalift™

Hollow Fiber

Flat Plate

Estimated Life

10+ years

10+ years

5-7 years

10+ years

MLSS Range

≤20,000 mg/L

1,000 – 20,000 mg/L

8,000 mg/L

8,000 – 18,000 mg/L


50-100 gfd

20-30 gfd

5-8 gfd

8-20 gfd


Not Required



Membrane Damaged if backwashed


Skid Mounted

Skid Mounted

Membrane Tank

Membrane Tank

System Energy

4-6 KWhrs /M3

0.4 Kwhrs / M3

.4 Kwhrs / M3

0.4 Kwhrs / M3


10-50 psig

1-3 psig

7-10 psig

1-3 psig


There are several membrane configurations available for MBR applications.  

For more information and to learn which membrane technology is right for your application, please contact us today.


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Dynatec is an industry leader in providing membrane bioreactors and wastewater membrane
systems since 1978 in industrial and municipal applications.

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