A compact installation
to reuse your wastewater
A Membrane Bioreactor (MBR) is a high-performance and compact wastewater treatment plant which combines a membrane filtration system with a biological process. This results in a high-quality effluent that can be reused. In the bioreactor, activated sludge feeds on the incoming wastewater, converting organic matter into harmless substances. The activated sludge is transferred to a membrane tank where the membrane filtration system separates solids from clean water.
There are two MBR configurations. The first is the submerged or immersed Membrane BioReactor (sMBR of iMBR). In this configuration the membrane is submerged in the biological medium. Secondly, there is the side stream Membrane BioReactor (ssMBR). Here the membrane is located outside the bioreactor, as an additional step after biological treatment.
PROS AND CONS
The submerged MBR is the preferred configuration due to its simplicity and relatively low power requirement. The aeration fulfils two functions; keeping the membranes clean and providing oxygen to the activated sludge. However, the amount of oxygen that can be dissolved and beneficially used is limited. Aeration below a certain level may be beneficial for the oxygen uptake, so it offsets the aeration of the bioreactor. Above this level the aeration does not benefit oxygen uptake and is therefore lost. It is therefore important to minimize aeration in the membrane section as much as possible. In contrast, the side stream MBR configuration has its own set of pros and cons. The membrane’s location outside of the bioreactor makes it somewhat easier to clean, but due to the high crossflow velocity of sludge being pumped through tubular membranes, the power consumption is massive. It is also important to note that the membrane’s placement outside of the bioreactor requires additional piping, which can increase overall costs.
Despite these differences, both configurations serve the same purpose of purifying wastewater, and they can be used in a variety of settings, including industrial and municipal wastewater treatment plants. Regardless of which configuration is chosen, it is essential to ensure that the membrane is adequately cleaned to maintain its efficiency and prolong its lifespan.
Submerged Membrane BioReactor