MBR is one of the predominantly used Filtration Technology in Sewage Treatment Plant
The Membrane Bioreactor technology is one of the wastewater treatment technologies which is a combination of Suspended growth biological treatment process along with membrane filtration. The technology is used in Municipal as well as industrial wastewater treatment processes.
Screening (Coarse & Fine), oil & Grease removal are prim most important before the MBR scheme. The MBR treatment consists of different stages such as the Activated sludge process, in a Bioreactor where microorganisms grow & multiply in presence of Dissolved Oxygen (DO), MBR Tank has membrane module cassettes where filtration occurs.
The overflow from the Bioreactor goes to the MBR tank. Biomass is retained in the MBR tank & recycles back to the bioreactor continuously to maintain the MLSS-MLVSS concentration & avoid sludge aging. Water passes through 0.04-micron membrane pores and gets filtered.
The system operates in two modes Permeate cycle & the Relaxation cycle. MBR eliminates the Tertiary polishing treatment of sand & carbon filters. Maintenance cleaning & Recovery Clean are the two membrane cleaning techniques followed.
1. The MBR technology aims to remove organic compounds (COD and BOD), suspended matter, nutrients (nitrogen and phosphorous) and bio-accumulative or bio-degradable micro pollutants.
2. The biological conversion processes are the same as those described for active sludge systems for COD removal, nitrifying active sludge and nitrifying/denitrifying active sludge.
3. The presence of membranes ensures complete retention of the biology and for complete removal of the suspended matter
4. Because bacteria are kept longer in the reactor, the likelihood is greater that difficult to degrade or larger components are degraded. Compared to a conventional system, the removal of suspended matter almost always results in a low COD value in the effluent. The absolute COD value is determined by the quality of the influent.
| Activated Sludge Process | MBBR - Moving Bed Bioreactor | MBR - Membrane BioReactor | |
| Process Type | Suspended Growth | Attached Growth | Biological + Filtration |
| Area Footprint | Maximum | Moderate | Minimal |
| Treatment Efficiency (COD, BOD, TSS) |
80- 90 % Reduction | 90-95 % Reduction | Reduction |
| Water quality & Consistency | Low quality & Consistency | Moderate quality & consistency | Excellent quality with High consistency |
| Required Level Of Manual Intervention | Medium | High | Low |
| Electro - Mechanical & Civil cost | High | High | Low-Moderate |
| Maintenance | Difficult | Difficult | Easy |
| Water Recovery | 80-90 % | > 90 % | > 95 % |
| Enhancement of Treatment capacity | Low chances | Enhances by 5-10 % | Enhances by > 3 X |
| Sludge handling | Require Periodic Sludge Wasting Intern Frequent Sludge Handling Equipment Usage | Require Periodic Sludge Wasting Intern Frequent Sludge Handling Equipment Usage | Highly Stabilized Sludge Reduces Sludge Handling Equipment Footprint |
| Electrical Consumption | Medium | Medium | Moderate |
