Three-phase internal circulation biofilm treatment technology

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Three-phase internal circulation biofilm treatment technology (municipal wastewater, industrial wastewater with medium to low concentrations) 【Technology name】Three-phase internal circulation biofilm treatment technology 【Technical details】This technology combines the advantages of biological contact oxidation and biological filters, saving 30% energy compared to traditional processes. 【Application Scope】Municipal sewage, medium-to-low concentration industrial wastewater, and polluted rainwater 【Related Topic】Lakes 【Technical Development Stage】Engineering demonstration 【Basic Principle】This integrated process combines the advantages of biological contact oxidation and biological filtration; it is characterized by a dual-sleeve structure for the main reactor – the inner sleeve is used for biological contact oxidation with semi-soft suspended fillers, while the outer sleeve serves as a biological filter filled with shale ceramsite ； Aeration at the bottom of the inner cylinder drives water flow to create a circulation between the packing area and the filter bed, thereby establishing an internal circulation within the reactor ； At the same time, ventilation openings are provided on the outer cylinder wall, and a height-to-diameter ratio of 4-8 is used to create a strong suction effect within the outer cylinder filter bed, resulting in good ventilation performance and low energy consumption ； After being treated by biological contact oxidation in the inner cylinder, the wastewater is circulated internally and dripped from top to bottom into the biological filter through a water distributor. The water flow is highly turbulent, ensuring thorough contact between the biofilm on the filter media, the wastewater, and the air – thus facilitating good oxygenation and rapid transfer of pollutants ； Furthermore, when there is an impact load, most of the pollutants are treated within the biological contact oxidation tank, overcoming the drawback of single biological filters becoming clogged easily under such loads. Therefore, this three-phase internal circulation biofilm reactor combines the advantages of biological contact oxidation and biological filters, while overcoming the shortcomings of traditional systems such as high aeration energy consumption, poor resistance to load fluctuations, insufficient oxygen supply, and tendency to clog. This leads to reduced energy consumption, improved resistance to load changes, a smaller footprint for the wastewater treatment system, as well as lower costs associated with its construction and operation ； The system achieves good pollutant removal performance and water quality, while being low-energy-consuming, efficient, and stable. It simultaneously enables the distribution of gas, liquid, and solid phases in different functional zones within the reactor; combined with aeration control, this facilitates an optimal allocation of aerobic, anaerobic, and anoxic operations, thereby improving aeration efficiency. 【Process Flow】After being treated by biological contact oxidation in the inner cylinder, the wastewater undergoes internal circulation and is dropped from top to bottom into the biological filter through a water distributor. The water flow is highly turbulent, allowing for thorough contact between the biofilm on the filter media, the wastewater, and the air, before the water is discharged. 【Key Technologies】1. Technology for rapid membrane formation on packing materials ； 2. Optimization techniques for the internal structure of reactors ； 3. Aeration and reactor flow pattern optimization techniques ； 4. Technology for the efficient, low-consumption, and stable operation of coupled reactors ； 5. Three-phase biofilm coupling technology ； 【Source of Technology and Overview of Intellectual Property】This technology is an integrated system developed independently for this project; a **patent has been applied for. The title of the patent is: Biofilm Reactor, Wastewater Treatment System, and Method for Treating Wastewater. Application number: 201110134094.8【Innovations, Advantages, and Applicability】Innovations: This technology combines the advantages of biological contact oxidation and biological filtration, while overcoming their respective disadvantages, thereby improving the efficiency of pollutant removal. Advantages: 1) Saves over 30% more energy compared to traditional biofilm processes ； 2) The hydraulic retention time is reduced by 1/3 ； 3) The removal rate of major pollutants is higher than 60%. Applicability: This technology is suitable for treating municipal wastewater, industrial wastewater with medium to low concentrations, and polluted rainwater, and can effectively reduce pollutants such as N and P. There is a large amount of industrial wastewater with moderate to low concentrations from direct discharges into various rivers within the Chaohu Lake basin; this technology can be applied to prevent pollutants from reaching rivers and lakes at the source. 【Application Case】Applicant: Chaohu Pollution Control and Comprehensive Development Co., Ltd. This technology was applied by Wanwei High-Tech Materials Co., Ltd. to the treatment of polluted rainwater within its factory premises, with good performance – it is capable of reducing major pollutants by over 60%. Processing capacity: 800 t/d; Project area: 1,040 m2; Completion date: End of 2009; Operation period: March 2010 – April 2011; Total investment for the demonstration project: 1.2 million yuan