Membrane BioReactors for WasteWater Treatment

The process can come in many configurations, but is based on a membrane which allows water to pass through while containing the aerated biomass which is consuming the carbonaceous BOD from the wastewater. The membrane must be sized so that the flow into the reactor is the same as that through the membrane.

There are several advantages, no need for secondary clarifier's or disinfection of effluent would be the main ones. You still need to waste a portion of secondary sludge from the system.

Big disadvantage is cost, but is becoming more viable with improved technology

Disinfection is still required when using the MBR process!

Please explain?

drill down these searched terms. They should include some data for you.

http://www.google.com/search?hl=en&q=%22bod%22+%2Breduction+%2Bbiomass+%2Bmembrane&btnG=Google+Search

I don't know if the American Water Works Association (AWWA) has anything on this topic, but I'm sure a post to them would be helpful. --JMM

While high on power consumed per volume treated in comparison with other processing techniques, the footprint of an MBR plant is rather low, enabling it to be added to an existing works to increase capacity often without significant land-take.

The technology is relatively young, and the industry in general rather conservative. MBRs have made significant advances in locations where land values and occupancies are high, being big news in Japan while making inroads into European and north American countries in certain areas. An MBR has been added to Westbury WwTW recently, giving a drinkable permeate(!) from a plant handling untreated domestic sewage. The plant's footprint is smaller than a tennis court.

http://www.copa.co.uk/ for more information, though the 'usual disclaimer' does not apply.

Membrane bioreactors are essentially a combination of extended aeration activated sludge and ultrafiltration technologies. An MBR is a 2-stage reactor. The first stage is a convention AS reactor and has fine aeration bubbles. Most of the BOD is oxidized here. The second stage combines CAS and UF. Instead of pumping the water through the membranes as in a conventional UF system, it is sucked through it. The bacterial sludge will naturally be sucked as well, but will be filtered out by the membrane, resulting in a heavy buildup of bacterial sludge on the membrane cassettes. Coarse aeration is applied here, directly under the membrane cassettes. This serves 2 purposes: it provides a heavy load of oxygen for the bacteria, and helps prevent an excessively heavy sludge buildup that would have a detrimental effect on the system. By combining UF with CAS, the MBR does away with the need for secondary settling, coagulation, flocculation, sludge thickening and filtration, greatly saving space in the plant. I hope this answers your question.

please find attached information at the below site

www.zenon.com

Regards

Ayub