MBR Intelligent Greywater Reuse Integrated Treatment Equipment
The MBR Sewage Treatment Equipment, utilizing the Membrane Bioreactor (MBR) technology, is a new device that combines biological treatment with membrane separation techniques, replacing the traditional secondary sedimentation tank. It effectively separates solids from liquids, yielding stable reclaimed water for direct use. It also maintains high microbial concentrations within the bio-reactor, produces minimal residual sludge, and efficiently removes ammonia nitrogen. The effluent has near-zero suspended solids and turbidity, with significantly reduced bacteria and viruses. It is energy-efficient and occupies less space. Research on using MBR for wastewater treatment began in the 1970s in the United States, Japan, South Africa, and many European countries. The water source includes 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, boasts several characteristics:
(1) Efficiently separates solid and liquid, 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, produces high-quality effluent, and typically can be reused without undergoing tertiary treatment.
(2) Maintains high biomass concentration within the biological treatment unit, significantly increasing the volumetric loading, while the efficiency of membrane separation drastically reduces the hydraulic retention time of the treatment unit, consequently 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), facilitating smooth metabolic processes within the system.
(4) Increases the retention time of some large, non-degradable organic molecules, facilitating their decomposition.
〔5〕Like other filtration and separation technologies, membrane treatment techniques experience clogging of the membrane as a filtration medium over time during continuous operation. The water flux through the membrane gradually decreases with operating time. Effective backwashing and chemical cleaning can slow down the decrease in membrane flux, maintaining the effective service life of the MBR system.
(6) MBR technology application in urban sewage treatment is characterized by its simple process and ease of operation, enabling full automatic operation and 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) before entering the reclaimed water storage pond. The backwash pump uses treated water from the cleaning pool to backwash the membrane treatment equipment, with the backwash wastewater returned to the equalization pond. The lift pump's on/off is controlled by the water level within the bioreactor. 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 flush valve and reagent recirculation valve, start the reagent circulation pump, and perform the chemical cleaning operation.
