The Ozone Mixing Tower is a core equipment used in water treatment systems to efficiently dissolve ozone, achieve water quality sterilization and oxidation purification. By fully mixing ozone gas with water and utilizing the strong oxidizing properties of ozone to remove microorganisms, organic matter, and odors in water, it is widely used in scenarios such as drinking water disinfection, sewage treatment, and swimming pool water purification. The following provides a detailed explanation from three aspects: working principle, structure, and function:
1、 Working principle
Ozone (O3) is a strong oxidant (with a redox potential of 2.07V, higher than chlorine gas), but its solubility in water is low (about 0.6-0.8mg/L at room temperature and pressure), and it is easily decomposed (with a half-life of about 20-30 minutes). The core principle of the ozone mixing tower is to enhance gas-liquid contact through a special structure, improve the dissolution efficiency of ozone in water, and enable ozone to fully react with pollutants in water. The specific process is as follows:
Ozone preparation and transportation:
Ozone is prepared by an ozone generator through high-voltage discharge (air or oxygen source) and transported through pipelines to the gas distribution device at the bottom or middle of the mixing tower.
Gas liquid mixing stage:
Water enters from the top of the tower and is evenly distributed along the packing or water distribution device, forming a continuous water film or droplet;
Ozone gas is released from the gas distribution device at the bottom or middle of the tower (such as microporous aeration disc, jet injector), and moves upward in the form of small bubbles (diameter ≤ 1mm);
Gas liquid two-phase flow in reverse or in the same direction inside the tower, increasing the contact area (30-50 times higher than traditional aeration tanks) and prolonging the contact time (usually 3-10 minutes) through surface contact of packing, bubble collision, turbulent stirring, and other methods, enabling efficient dissolution of ozone (dissolution rate can reach 80% -95%).
Oxidation reaction stage:
Dissolved ozone (O3) reacts with pollutants in water:
Sterilization: destroys the cell membrane and DNA of bacteria and viruses, with a sterilization rate of ≥ 99.99% (acting 300-600 times faster than chlorine gas);
Oxidation of organic matter: decomposition of pesticides, humic acid, algal secretions, etc., reducing COD (chemical oxygen demand) and TOC (total organic carbon);
Remove odors/pigments: oxidize sulfides (such as H ₂ S) and iron manganese ions in water, eliminate fishy odors and colored substances.
Exhaust gas treatment:
Unsolved residual ozone (usually ≤ 0.1mg/L) is discharged from the top of the tower and converted into oxygen (O ₂) through a tail gas disruptor (heating or catalytic decomposition) to avoid environmental pollution.
2、 Core Structure
The structural design of the ozone mixing tower is centered on “strengthening gas-liquid contact and improving dissolution efficiency”, mainly composed of the following parts:
1. Tower body
Material: Select according to water quality
Drinking water/food industry: 304 or 316L stainless steel (corrosion-resistant, solvent-free, inner wall polished Ra ≤ 0.8 μ m);
Wastewater treatment/industrial scenarios: FRP (fiberglass, acid and alkali resistant) or PVC (low-cost, suitable for room temperature and low pressure).
Shape: cylindrical (reducing dead corners and making water flow more uniform), height 3-8m (designed according to processing capacity and contact time), diameter 0.5-3m.
Interface: The top is equipped with water inlet and exhaust outlet, the bottom is equipped with water outlet and ozone inlet, and the side is equipped with maintenance manhole.
2. Water distribution device
Function: evenly distribute the incoming water at the top of the tower, forming a continuous water film to avoid local dry areas or water flow short circuits.
Type:
Porous plate water distributor: uniformly distributed with small holes of diameter 3-5mm on the plate, suitable for high flow scenarios;
Nozzle type water distributor: a rotating or fixed nozzle that forms a fan-shaped water curtain, suitable for medium flow rates;
Trough type water distributor: Water is directed to the packing material through an overflow trough, suitable for high turbidity water (to avoid blockage).
3. Gas distribution device
Function: Disperse ozone gas into tiny bubbles and increase the contact area with water.
Type:
Micro porous aeration disc/tube: made of ceramic or EPDM rubber, with a pore size of 10-50 μ m, producing bubbles with a diameter of ≤ 1mm, high dissolution efficiency (≥ 90%), but prone to clogging (requiring pre-treatment to remove suspended solids);
Jet type air distributor: utilizing the high-speed flow of water to generate negative pressure, inhaling and shearing ozone into microbubbles, suitable for small and medium flow rates, with strong anti clogging properties;
Spiral mixer: using spiral blades to rotate and mix gas-liquid in the pipeline, suitable for integrated small equipment.
4. Packing layer (optional)
Function: Increase the gas-liquid contact area and prolong the contact time (a water film is formed on the surface of the packing, and bubbles slowly rise in the gap).
Material: PP (polypropylene), PVC or ceramic, with shapes of Ball ring, Rascal ring, and stepped ring (specific surface area 80-200m ²/m ³).
Attention: High turbidity water (such as sewage treatment) is usually not filled with fillers to avoid blockage; Drinking water treatment can be filled with fillers to improve efficiency.
5. Exhaust gas disruptor
Installation location: at the exhaust outlet of the tower top.
operation mode:
Heating decomposition: Heating the exhaust gas to above 300 ℃ decomposes ozone into O ₂;
Catalyst decomposition: MnO ₂ or activated carbon catalyst is used to decompose ozone at room temperature (suitable for low concentration exhaust gas).
6. Auxiliary equipment
Ozone generator: provides ozone gas source (the output is designed according to the treated water volume and ozone dosage, usually 1-5g/m ³);
Water pump: transports the water to be treated into the mixing tower;
Online monitoring devices: ozone concentration detector (monitoring dissolved ozone concentration in water, usually controlled at 0.3-0.8mg/L), ORP (oxidation-reduction potential) meter (indirectly reflecting ozone activity).
3、 Main function
The ozone mixing tower plays three core roles in water treatment: sterilization and disinfection, oxidation purification, and water quality improvement, by efficiently dissolving ozone
1. Efficient sterilization and disinfection
Killing bacteria (such as E. coli and Legionella), viruses (such as influenza virus), algae, and protozoa (such as Cryptosporidium) in water, the sterilization rate is much higher than traditional chlorine disinfection, and there are no chlorine disinfection by-products (such as trichloromethane). It is suitable for scenarios with high safety requirements such as drinking water, swimming pool water, and medical wastewater.
2. Oxidation to remove organic matter and pollutants
Decompose pesticide residues (such as organophosphates and pyrethroids), industrial organic compounds (such as benzene derivatives), endocrine disruptors (such as bisphenol A) in water, reduce COD and TOC, and improve water quality safety;
Oxidation removes iron (Fe ² ⁺ → Fe ³ ⁺) and manganese (Mn ² ⁺ → MnO ₂) ions from water, avoiding their deposition in pipelines or causing yellowing of water color;
Oxidative decomposition of sulfides (H ₂ S → H ₂ SO ₄) and ammonia nitrogen (NH ∝→ NO ∝⁻), eliminating fishy odors and improving water quality sensory indicators.
3. Strengthen the effectiveness of subsequent processing
In sewage treatment, ozone oxidation can improve the biodegradability of recalcitrant organic matter (B/C ratio increased by 0.1-0.3), creating conditions for subsequent biochemical treatment;
In the preparation of pure water, ozone oxidation during the pretreatment stage can remove organic matter and microorganisms, reduce the risk of fouling of reverse osmosis membranes, and prolong membrane life.
4. Environmentally friendly and residue free
Ozone ultimately decomposes into oxygen (O3 → O ₂), which causes no secondary pollution and is more environmentally friendly than chlorine disinfection. It is particularly suitable for industries such as food and medicine that strictly limit residual chemicals.
summarize
The ozone mixing tower is the core equipment of ozone water treatment technology. By optimizing the gas-liquid contact efficiency, it solves the problem of low ozone solubility and fully utilizes its strong oxidizing properties. Its structural design revolves around “efficient mixing” and is widely used in scenarios such as sterilization, oxidation of organic matter, and improvement of water quality. It has the advantages of high efficiency, environmental protection, and no residue, and is an important deep purification unit in modern water treatment.
Post time: Aug-06-2025