Europe - MBR Technology
An MBR is a biological purification treatment by activated sludge, which incorporates a membrane for separating clarified water and sludge, obtaining very high quality purified water. An activated sludge reactor needs biodegrable matter, micro nutrients and an external oxygen source, in addition to stable temperature conditions, all to induce the development of microorganisms able to assimilate organic matter transforming it into insoluble microorganisms that can be removed.
Comparison between MBR and Active Sludge
In a conventional activated sludge treatment, the separation of insoluble microorganisms converted to sludge is performed by decantation, so that the conditions of treatment should be controlled to inhibit the growth of microorganisms that float, that form colloidal dispersions, that inhibit floc formation, etc. This type of control over the activated sludge process is complex, however it is well investigated and resolved. Engineerings have design parameters to be able to maintain these conditions.
- V: reactor volume, in m3
- So: influent DBO5, in mg/l
- S: effluent DBO5, en mg/l
- Cm: mass load, in Kg Applied DBO5/kg SSVLM-d
- SSLM: suspended solids in the mixed liquor, in mg/l
- Q: daily feed rate, in m3/d
In a membrane bioreactor, limiting parameter is the filterability of liquor mixture and not the sedimentation ability, so the process is simpler, since we should not worry about those microorganisms that float, are in colloidal State, etc. So, we would be able to work with rates of suspended solids in the liquor mixture up to 15,000 mg/l, while maintaining acceptable rates of filterability. This parameter of filterability is related to the pore size of the membrane and the size of the particles in the liquor mixture.
We note that in a membrane bioreactor by increasing SSLM, decrease the volume ofreactor, in the same way if you keep the volume of the reactor, the system will have greater water treatment ability.
While in a conventional reactor of activated sludge, it is necessary to incorporate a stage of filtration to remove all not settleable solids that have escaped from the decanter and also a stage of disinfection after the stage of sedimentation, these operations are performed in a single step in a bioreactor of membranes, generating water ultrafiltradas and disinfected, free of viruses and bacteria.