In conventional activated sludge processing, solid-liquid separation is performed in a settling tank. However, in the MBR system it is performed in a membrane module. Consequently, a settling tank is not required in MBR systems, a high MLSS concentration can be maintained, and 100% separation of SS larger than the membrane pore diameter is possible.
Conventional activated sludge
Membrane bio reactor (MBR)
There are two types of MBR system:
- Integrated MBR systems which place membrane modules in aeration tanks.
- Separated MBR systems which place membrane modules in seprate membrane tanks.
Characteristics and Applications
Space saving, high quality of treated water and ease of maintenance are unique properties of this MBR system. Appling this MBR system will reduce footprint to 1/3 space that have being used in conventional methods. MBR can treat a sludge that is 5 times thicker compared to conventional methods. For this reason, it can treat more water even with smaller biological tank.
MBR can be used the only treatment unit before RO plant to not only decrease the TSS but also it can remove notable amount of COD, BOD and total nitrogen and phosphorous.
another example of using MBR in when oily waste water is required to treated with better final effluent quality in terms of BOD and SS.
The benefits of low footprint
Ultra Hollow fiber specification:
• Fineness: 0.05 micron
• Material: PVDF
• Advantageous over flat sheet:
o More membrane surface area
o Membrane tank size reduction
o Reduced aeration demand
o Reduced energy consumption
o Reduced Capital and Operational costs.
There is no need to backwash just 7-minute filtration and 1-minute relaxation is required
Petrochemical plant wastewater recycling
Mitsubishi Chemical Engineering Co.
Petrochemical Plant Wastewater
- Reuse purified terephthalic acid (PTA) plant wastewater as cooling
tower makeup to reduce the environmental load associated with
effluent disposal and to cut the water bill
- Install all the membrane modules in the existing 10 meter depth tank
without a shutdown of the WWTP
- Retrofit of the existing WWTP with an MBR-RO system to obtain
reusable water for the purpose
- Use of the existing beam to hang membrane modules to eliminate
the guide pipe foundation work which requires a WWTP shutdown
- Reuse up to 70% of the wastewater (4,200m3/day) as cooling tower
- No WWTP downtime
Process flow diagram