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What are membrane bioreactors?

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A graphic of a complete immersed MBR treatment scheme

An introduction to MBRs

‘Membrane bioreactor’ (MBR) is generally a term used to define wastewater treatment processes where a perm-selective membrane, eg microfiltration or ultrafiltration, is integrated with a biological process specifically a suspended growth bioreactor.

MBRs differ from ‘polishing’ processes where the membrane is employed as a discrete tertiary treatment step with no return of the active biomass to the biological process.

Almost all commercial MBR processes available today use the membrane as a filter, rejecting the solid materials which are developed by the biological process, resulting in a clarified and disinfected product effluent.

A membrane bioreactor is essentially a version of the conventional activated sludge (CAS) system:

Fundamentals of MBR design − the immersed membrane bioreactor process

Fundamentals of MBR design − the immersed membrane bioreactor process Source: Judd Water & Wastewater Consultants / YouTube

While the CAS process uses a secondary clarifier or settlement tank for solid/liquid separation, an MBR uses a membrane for this function. This provides a number of advantages relating to process control and product water quality.

Watch our video for a brief introduction to MBR technology key parameters:

Key MBR operation and maintenance parameters – membrane side

Key MBR operation and maintenance parameters – membrane side Source: Judd Water & Wastewater Consultants / YouTube


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Excellent information on your blog, thank you for taking the time to share with us. Amazing insight you have on this, it's nice to find a website that details so much information about different artists.
Contact us :-

Alireza Hajializadeh

We are installing a MBR system in the industrial town wastewater treatment plant.
Do you think the polymer in industrial effluents can shorten the useful life of our system?

Simon JuddAlireza Hajializadeh

Not sure. It’s worth posting this query on The MBR Group on LinkedIn

Alireza HajializadehSimon Judd

Thank you for your attention
We use to separate the sludge from the device Multi disc screw press, that the effluent of the device has a large amount of polymer.

Sean Camilleri

Can I kindly ask whether it is possible to have the anoxic tank/zone, serving as a sediment/septic tank, all regards to a small system of 10m3/hr, with no mechanical agitation?

Thanks & Kind Regards,

Avinash Deokate

Dear Sir,
WE require 500 KLD MBR technology Sewage Treatment Plant. Please mail me quotation immediately.
Thanks and Regards,

Avinash Deokate
+91 9822296640
7, Sunrise Apartment, Opposite Ajinkya Big Bazar, Sai Ganesh Nagar, Bhigwan Road, Baramati 413102, Dist. Pune. M. S. INDIA

Claire JuddAvinash Deokate

Dear Avinash

Companies who might be able to help are listed in our Technology Suppliers and Membrane Products directories:




hello thanks to your useful site and information, i cant open the link of your site, please guide me. for example this link :

Claire JuddSara

Hi Sara - the link works for us. You could try another browser or go to YouTube and then search for our channel which is 'Judd Water and Wastewater Consultants'. You will find the video on there. Hope that helps.

About this page

'What are membrane bioreactors?' was written by Simon Judd

This page was last updated on 19 August 2021


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