Wastewater treatment technology by MBR
MBR technology: Aerobic technology combined with MBR membranes is one of the most advanced technology options. The tanks in the MBR technology block unit also include treatment tanks such as conditioning, anoxic, aerobic, and sludge incubation. However, the aeration tank, settling tank and sterilization tank were replaced by the MBR membrane storage tank.
MBR is a technology that combines two basic processes in a single unit:
(1) Biodegradation of organic matter
(2) The technique of separating bacterial biomass by micro-flitration.
In the tank that maintains the suspended growth sludge system, the reactions take place in the tank like other normal biological processes, the treated water is separated by a membrane filter system with a membrane size fluctuating about 0.1 -0.4 microns. “Source: Manem and Sanderson, 1996”.
Figure 1. Diagram of wastewater treatment by MBR technology.
Advantages of the option:
Ensure the wastewater treatment capacity after the system reaches level A of QCVN 14:2008/BTNMT – National technical regulation on domestic wastewater.
Treated wastewater has very high quality, usually applied to systems with water quality requirements equivalent to column A QCVN 14:2008 National Technical Regulation on domestic wastewater.
Withstands shock conditions in terms of both effluent flow and contaminant concentration due to high sludge concentration operations.
The output quality almost completely eliminates bacteria, pathogens and relatively small particles.
Minimum area required compared to other options, as the structure is designed to operate at high sludge concentration, hence the small building volume.
Minimize construction costs compared to other options because the construction volume when using the MBR option is the smallest.
The water retention time of the tank is short because the sludge concentration is maintained at a high level, increasing the biological efficiency from 10-30%, no need for secondary settling tanks, disinfection tanks, so the construction volume is reduced. .
The wastewater treatment technology line according to the selected option includes the following treatment stages: MBR technology
Figure 2. Technological diagram of wastewater treatment system using MBR technology.
Description of project items:
Wastewater receiving pit: Domestic wastewater generated from items of the tourist area is collected by self-flowing pipes and then pumped to the wastewater receiving pit. At the location where the treatment station is located is also the end of the drainage route. Waste water will be flowed to the grease separation tank.
The grease separation tank is responsible for removing grease and hydrocarbons before flowing to the conditioning tank.
Fine screen box: Waste water after being collected by the drainage network will be mechanically treated by a system of fine screen boxes placed in the conditioning tank. The fine screen box is responsible for separating the garbage mixed in the wastewater, to protect the pump. The fine garbage box is designed with SUS 304 stainless steel material, equipped with a lifting and lowering system, making the periodic garbage collection process convenient, saving investment costs compared to the plan of using the machine. mechanical waste separation. The fine screen is responsible for separating the waste less than 5 mm in size from the wastewater before it flows into the biological tank to protect the operation of the MBR Membrane Modules.
Conditioning tank: Receiving wastewater, regulating the flow of wastewater. At the conditioning tank, there is a flow-regulating pump system that works according to the signal of the water level indicator.
Sludge tank: Store and treat the sludge generated in the treatment works.
Anoxic biological tank: Synthetic treatment of pollutants containing Nitrogen and Phosphorus. Here, the process of reducing NO3– to N2 gas takes place in an anaerobic environment, NO3– plays the role of accepting Electron. Bacteria gain energy for growth from converting NO3– into N2.
Aerobic tank combined with MBR membrane filter: Remove suspended sediments, separate sludge, purify water, synthesize organic matter. The MBR membrane filter tank also has the task of thoroughly treating organic matter, nitrifying ammonium, and removing a part of pathogens in wastewater. The fine foam gas distribution system is installed under the treatment tank to increase the efficiency of oxygen dispersal into the water. This amount of oxygen is responsible for directly oxidizing organic matter, a part of the remaining oxygen is responsible for mixing the activated sludge with wastewater. The MBR filter module is responsible for separating sludge, and bacteria in wastewater, maintaining the sludge concentration in the project, and ensuring the quality of water after treatment.