With the expectation of an increasingly improved living environment, domestic wastewater management is made easier to suit the inevitable development of society and improve heavily polluted water resources. masonry. We will together with customers contribute to the better, more efficient, and cleaner, and more beautiful, residential wastewater management. The composition and properties of domestic wastewater depend a lot on the source of wastewater (residential areas, restaurants, hotels …). Features of domestic wastewater include 2 types: – Wastewater contaminated by human secretions from toilets (wastewater from the toilet). – Wastewater contaminated by domestic wastes: residue, kitchen grease, detergents, surfactants from bathrooms, floor cleaning water.
Some popular domestic wastewater treatment technologies are being applied today: 1. AEROTANK Tank Technology (Traditional): Aerotank works based on strains of microorganisms capable of oxidizing organic substances in wastewater. The tank is simply a rectangular block inside with a gas distribution system (air blower plate or gas distribution tube) to increase the amount of dissolved oxygen (DO in water). Aerotank tanks with a height of 2.0 m or more aim that when aerated in, the amount of air can dissolve in the water, if it is low, it will explode because oxygen has not dissolved.
Aerobic activated sludge with organisms growing in suspended form in Aerotank tanks. In the condition of continuous aeration, activated sludge is in contact with wastewater, decomposition of organic compounds will occur. Such aeration aims to keep the sludge operating in a suspended state and continuously providing enough oxygen for the wastewater treatment microorganisms
Figure 1. Diagram of technological process of domestic wastewater treatment (Aerotank tank) 2. SBR Tank Technology: SBR is a form of Aerotank tank, developed on the basis of activated sludge treatment, operated in continuous batches and controlled over time, is a biological treatment facility of activated sludge, in In that sequence, the processes of blowing air, sedimentation and decantation of wastewater take place. Due to the intermittent operation, the minimum number of compartments of the tank is 2. Divided into 5 phases (filling – reacting, blowing – settling – draining – waiting) and aerated with air blowers combined with mechanical stirring equipment, the operating cycle of the tank compartment is controlled by relay. le time. SBR tanks can perform the processes of denitrification, nitrification, denitrification and biochemical decarburization because the aerobic, anaerobic and anaerobic processes in the tank can be adjusted by providing oxygen.
Figure 2. Diagram of domestic wastewater treatment process (SBR tank)
3. MBR Tank Technology: MBR technology is a microbiological treatment technology for wastewater by membrane filtration method. MBR stands for Membrance Bio Reator (Membrane Biofilter Tank). This is a technology that has been researched and applied by domestic and foreign experts to wastewater treatment technology. MBR technology is a combination of both biological and physical methods. Each MBR unit is composed of many hollow fibers linked together, each hollow fiber is structured like a filter with very small filter pores that some microorganisms are unable to penetrate. These MBR units will link together into larger modules and placed in treatment tanks. The mechanism of action of microorganisms in MBR technology is similar to aerobic activated sludge tanks, but instead of separating biological sludge by sedimentation technology, MBR technology is separated by membrane.
Microorganisms, pollutants, and mud are completely trapped at the membrane surface. At the same time, only clean water can pass through the membrane. The clear water is pumped out, the sludge stays in the tank and periodically drained to the sludge tank. Because the membrane pore size MBR is very small (0.01 ~ 0.2 µm), the bio-sludge will be retained in the tank, high microbial density and treatment efficiency increase. The clean water is sucked into the tank and escaped without going through the sedimentation, filtering and disinfection tanks.
Figure 3. Diagram of technological process of domestic wastewater treatment (MBR tank) Comment: Each processing technology has its own advantages and disadvantages. Therefore, depending on each specific condition, Thanh An Company will advise customers on the most suitable treatment technology.