Heterogeneous catalysis ozone oxidation method for water treatment and device applied to the method

Abstract

The invention relates to a heterogeneous catalysis ozone oxidation method for water treatment and a device applied to the method. The device is mainly composed of a center contact tower, 1-4 catalytic oxidation towers and 1-4 root radial flow type connecting pipes. Water to be treated enters from a water inlet manifold on the top of a central contact tower, conducts reverse contact with ozone gas flow from a bottom aeration head, and then is sent to the catalytic oxidation tower through a diversion slope and a connecting tube. An ozone gas flow enters into the catalytic oxidation tower through an aeration disc, and flows in the same direction as water, so that the solid catalyst is in a complete fluidization state. A membrane separation component and a water outlet pipe used to achieve effluent separation are arranged in the middle of the catalytic oxidation tower, and the bottom of the catalytic oxidation tower is provided with a collecting bucket and a vent nozzle. Online monitoring of dissolved ozone concentration is employed to control adding amount of ozone dosage. Pressure operation of various towers is achieved by using ventilation pressure, and exhaust gas is discharged from the discharge tube on a gas collecting hood. Compared with the prior art, the invention uses micron sized solid catalyst to continuous treatment and has the advantages of high purifying efficiency, wide applicable range, and stable and flexible operations.

Description

technical field [0001] The invention relates to a water treatment method, in particular to a method for treating water by heterogeneous catalytic ozonation oxidation and a device used in the method, and belongs to the technical field of environmental protection. Background technique [0002] In the field of raw water purification and wastewater treatment, ozone (O 3 ) due to strong oxidizing properties (E 0 =2.07V), it is often used to achieve sterilization, decolorization and deodorization, removal of refractory pollutants and improvement of raw water biodegradability and other purposes. According to the principle of direct oxidation, O in water 3 It can preferentially destroy unsaturated and aromatic structures in organic matter, and convert macromolecular substances into small molecular products. However, as the reaction progresses, the removal rate of total organic carbon (TOC) in the system will be significantly reduced. At this time, if ozone is continuously added, ...

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Problems solved by technology

Existing heterogeneous catalytic ozonation water treatment devices cannot give full play to the advantages of heterogeneous catalytic ozonation water treatment. The generation of OH is limited; (2) In the existing device, the solid catalyst directly contacts with aromatics and hydrophobic organic substances in water, which will lead to the reduction of catalytic sites due to strong adsorption and weaken its reactivity; (3 ) In the existing equipment, the solid catalyst generally exists in the form of a fixed bed. The contact area between the solid catalyst and water is designed in this way, which leads to the inability to fully reflect the catalytic effect, also leads to uneven treatment, and increases the treatment time.

It is generally believed that when the particle size of the solid catalyst is less than 500 μm and it is in a fully fluidized state, the mass transfer resistance of ozone on its inner and outer surfaces will be effectively eliminated, the treatment efficiency of the reaction device will be significantly improved, and the hydraulic retention time will be greatly reduced. ; but the small-sized solid catalyst is easily lost with the effluent, which makes gas-liquid two-phase reactors equipped with traditional weirs (pipes), such as baffle contact tanks, spray towers, packed towers, and sieve tray towers, etc. The system cannot be guaranteed to obtain good operational stability, which is the main reason why the current dispersed solid catalyst cannot be practically applied

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