MBR Intelligent Greywater Reuse Integrated Treatment Equipment
The MBR wastewater treatment equipment utilizes Membrane Bioreactor (MBR) technology, a new device that combines biological treatment with membrane separation techniques, replacing the traditional secondary sedimentation tank. It efficiently separates solids from liquids, yielding stable reclaimed water for direct use. It also maintains high concentrations of microorganisms in the biological pond, 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 has low energy consumption and a small footprint. Research on using MBR for wastewater and effluent treatment began in the 1970s in the United States, Japan, South Africa, and many other European countries. Its water source is from domestic wastewater (such as shower, lavatory, laundry, kitchen, and toilet drainage) and cooling water.
MBR process characteristics
Membrane biological treatment technology, applied in wastewater recycling, boasts several characteristics:
(1) Efficiently separates solids from liquids, isolating suspended particles, colloidal matter, and microorganisms from the biological unit in wastewater from purified water. The separation process is simple, requiring minimal space, and the effluent quality is high, typically allowing for reuse without the need for tertiary treatment.
(2) Maintains high biomass concentration within the biological treatment unit, significantly increasing the volumetric load, while the high efficiency of membrane separation drastically reduces the hydraulic retention time of the treatment unit, correspondingly reducing the land area required for the bioreactor.
(3) Preventing the loss of various microbial populations promotes the growth of slow-growing bacteria, such as nitrifying bacteria, ensuring smooth metabolic processes within the system.
(4) Prolongs the residence time of some large-molecule, hard-to-degrade organic substances, benefiting their decomposition.
〔5〕Like other filtration and separation technologies, membrane treatment technology experiences clogging of the membrane as a filtration medium over an extended operation period. The water flux through the membrane gradually decreases with operating time. Effective backwashing and chemical cleaning can mitigate the decline in membrane flux, maintaining the effective service life of the MBR system.
(6) MBR technology application in urban wastewater treatment is favored due to its simple process, easy operation, and the ability to achieve fully automatic operation and management.
Process Description
Wastewater enters the equalization pond after passing through a格栅, then it is pumped into the bioreactor. The PLC controller is used to activate the aeration machine for oxygenation. 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 a rapid mixing method (sodium hypochlorite, bleaching powder, chlorine tablets) before entering the reclaimed water storage pond. The backwashing pump uses treated water from the cleaning pond to backwash the membrane treatment equipment, with the backwashing wastewater returned to the equalization pond. The lift pump's on/off is controlled by the water level within the bioreactor. The filtration operation of the membrane units and the backwashing 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 fluid valve and cleaning fluid recirculation valve, start the cleaning fluid circulation pump, and perform the chemical cleaning operation.
