Hitachi Compact MBR (Membrane Bioreactor) System is a compact- packaged and adopts membrane filtration process, which requires less space and yet provides higher treatment performance compared with the conventional treatment systems.
By combination of activated sludge treatment with immersed flat membrane modules, this new system can maintain the activated sludge concentration at a high-level in the reaction tank without use of a sedimentation tank for separation of liquids mixed with the activated sludge. As a result, yield of the treated water is at a higher quality than ever before, as well as space saving and reduced operation costs are realized. Since sludge control in a sedimentation tank is eliminated, this treatment system has a feature of lower maintenance.
Treated water can be used for toilet flushing, irrigation, landscaping, concrete mixing and curing, for cooling water and for industrial water.
"HITACHI Compact MBR" employs 2 or 3 membrane modules in a vertical formation, with each module containing multiple membrane sheets. Wastewater is effectively treated by simply passing through the flat sheet membranes.
The sewage is separated through suction and filtration, so that the filtrated water directly becomes treated water. Air is supplied from the air diffuser installed on the bottom of the aeration tank to prevent sludge from adhering to the membrane surface. Thus, the system can perform stable treatment without getting clogged.
We can provide various membrane unit from 50 m3/day treatment capacity. Our standardized Type is 250 m3/day, 500m3/day, and 750m3/day (Please refer to the following table). They are applicable to larger treatment plants by multiplying standardized MBR units. 50m3 / day and 100m3 / day units are also available.
| Capacity | Population(for reference) | Electricity | ||
|---|---|---|---|---|
| (m3/d) | Workforce Accomodation | Residence | Capacity | Consumption(kWh/d) |
| 250 | 1,500 | 1,200 | 13 | 203 |
| 500 | 3,000 | 2,500 | 24 | 374 |
| 750 | 4,000 | 3,800 | 33 | 540 |
(Remarks) Above energy consumption figures vary depending on actual operating conditions.
"HITACHI Compact MBR" can be utilized for many applications as follows;
| Membrane Specification | Type | Submerged flat sheet membrane - strong membrane surfaces which prevents filtration trouble |
|---|---|---|
| Material | PVDF ? smooth surface prevents clogging | |
| Pore Size | 0.1µm ? uniform distribution of pore diameter , high particle blocking performance, high water quality | |
| Membrane Area | 1m2/ element | |
| Flux | 0.8 m3/m2/d ? higher flux rate : higher treatment capacity | |
| Number of Stage | Maximum 3 stages ? energy & space saving | |
| Biological Treatment | Retention Time | 6 hours ? retention time is 1/4 compared with OD process |
| MLSS | 8,000 – 20,000mg/L | |
| Sludge | Generated sludge volume is 2/3 compared with OD process | |
| Sludge Treatment | Direct sludge dewatering is possible | |
| Space | Space is 1/3 less than OD process | |
The following water quality can be achieved by HITACHI Compact MBR. compared with conventional OD system.
| Item | Raw Water | Treated Water | ||
|---|---|---|---|---|
| Our Compact MBR | Conventional OD System | |||
| BOD | (mg/L) | 193 | 1.0 | 20 |
| COD | (mg/L) | 124 | 7.5 | 25 |
| T-N | (mg/L) | 38 | 5.7 | 5.7 |
| T-P | (mg/L) | 7.8 | 0.3 | 0.5 |
| SS | (mg/L) | 250 | <0.4 | 20 |
| Coliform | (CFU/mL) | 3.7×105 | Not Detected | <3000 |
| Escherichia Coli phage (Virus) | (PFU/100mL) | 3.6×105 | 1 | 2.7×102 |
(Remarks) The above figures are based on our estimates. Above figures vary depending on actual operating conditions, and water conditions.
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