Wastewater Treatment Blog

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What the Flux?

Peter Annunziato, P.E.
Posted by Peter Annunziato, P.E. on Jan 23, 2019 11:08:00 AM

What is Flux?

Simply put, the membrane flux is defined as the daily or hourly water flow through a membrane’s surface area (i.e. GPD/ft2), and the treated water that passes through the permeate.  The flux rate depends on the membrane type and several physical and environmental operating conditions.

Flux VariesFlux

First and foremost, the membrane flux rate varies upon the membrane type which includes, from largest to smallest pore size; Microfiltration, Ultrafiltration, Nano filtration and Reverse Osmosis. It also varies based on their configuration, which includes tubular, flat sheet, hollow fiber and spiral wound.  Membranes are used to treat everything from potable water through the gnarliest wastewater.

Flux Can Be Influenced

Other variables to consider are the physical and environmental conditions that influence flux during system operation, which include:

  • Type of water/wastewater and their constituents (i.e. minerals, organics, FOG, polymers, chemical compounds, etc.)
  • Water/Wastewater temperature
  • Water/biological sludge viscosity
  • Biological sludge age and overall health
  • System operating conditions such as operating pressures, water crossflow velocity, membrane fouling potential

So the next time you find yourself saying “what the flux”, bioprocessH2O has you covered and can provide an expertly designed membrane filtration system with a long and successful operating life.


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Topics: MBBR, pollutants, wastewater, membrane bioreactors, COD Removal, wastewater surcharges, MBR, Flux, wastewater flux