MBR Intelligent Greywater Recycling Integrated Treatment Equipment
The MBR Sewage Treatment Equipment, utilizing the Membrane Bioreactor (MBR) technology, is a new device that combines biological treatment technology with membrane separation technology, replacing the secondary sedimentation tank in traditional processes. It effectively separates solids from liquids, yielding stable, directly usable reclaimed water. It also maintains a high concentration of microorganisms within the biological pool, resulting in minimal residual sludge and highly effective removal of ammonia nitrogen. The effluent has near-zero suspended solids and turbidity, with significantly reduced bacteria and viruses. It operates with low energy consumption and requires minimal land area. Research on the use of MBR for wastewater and effluent treatment began in the 1970s in the United States, Japan, South Africa, and many European countries. The water source is from domestic wastewater (such as shower, lavatory, laundry, kitchen, and toilet drainage) and cooling water.
MBR Process Features
Membrane biological treatment technology applied in wastewater recycling has the following characteristics:
(1) Efficiently separates solids from liquids, isolating suspended matter, colloidal substances, and microorganisms lost from biological units in wastewater from purified water. The separation process is simple, requires minimal land area, and the effluent water quality is high, generally allowing reuse without the need for tertiary treatment.
(2) Maintains biomass at high concentrations within the biological treatment unit, significantly increasing the volume load, while the efficiency of membrane separation drastically reduces the hydraulic retention time, consequently minimizing the footprint required for the bioreactor.
(3) Preventing the loss of various microbial populations, it promotes the growth of slow-growing bacteria (such as nitrifying bacteria), thereby ensuring smooth metabolic processes within the system.
(4) Increases the retention time of some large molecular, difficultly degradable organic matter, facilitating their decomposition.
〔5〕Like other filtration and separation technologies, membrane treatment techniques may experience clogging of the membrane as a filtration medium over time during operation. The water flux through the membrane gradually decreases with operating time. Effective backwashing and chemical cleaning can slow down the decline in membrane flux, maintaining the effective service life of the MBR system.
(6) The application of MBR technology in urban wastewater treatment is advantageous due to its simple process, ease of operation, and the ability to achieve fully automated management.
Process Description
Wastewater enters the equalization pond after passing through a grille and is then pumped into the bioreactor. The PLC controller activates the aeration machine to oxygenate the water. The effluent from the bioreactor is pumped into the membrane separation unit, with the concentrated water returned to the equalization pond. The water from the membrane separation is chlorinated using quick-mix method (sodium hypochlorite, bleaching powder, chlorine tablets) and then enters the recycled water storage pond. The backwash pump uses treated water from the cleaning pond to backwash the membrane treatment equipment, with the backwash wastewater returned to the equalization pond. The lift pump is controlled by the water level within the bioreactor to turn on or off. The filtration and backwashing operations of the membrane units can be controlled automatically or manually. When chemical cleaning of the membrane units is required, close the inlet and wastewater recirculation valves, open the cleaning agent valve and the cleaning agent recirculation valve, start the cleaning agent recirculation pump, and perform the chemical cleaning operation.
