Integrated method and integrated device for ozone/photocatalytic oxidation-membrane separation for advanced wastewater treatment

Abstract

The invention relates to an ozone / photocatalysis oxidation-membrane separation integrated method for advanced wastewater treatment. First, an ozone / oxygen gas mixture is dissolved in the wastewater through a gas-liquid mixer to generate high-concentration dissolvable ozone and oxygen; the ozone and oxygen enter into a photocatalytic reactor and produce a large number of strong oxidizing agents such as hydroxyl radicals under the combined action of dual band ultraviolet (185nm + 254nm) radiation and a suspension nano TiO2 catalyst, and the strong oxidizing agents, dissolved oxygen and dissolved ozone cooperatively oxidize and remove removal toxic and harmful substances, odor smell, chroma, virus and bacteria in the water; and a three-phase fluid of wastewater, catalyst and gas passes through a ceramic membrane filter, the wastewater permeating through the ceramic membrane reaches the standard and is discharged, and the concentrated water with suspended catalyst failing to permeating through the ceramic membrane is returned to a backwater bin for further participation in the gas-liquid mixing and ozone / photocatalytic reaction. The process and device involved in the invention have the advantages of high wastewater treatment efficiency, high recovery rate of catalyst, high utilization efficiency of ozone and long service life of membrane.

Description

technical field [0001] The invention belongs to the technical field of water treatment, in particular to an ozone / photocatalytic oxidation-membrane separation integrated method and integrated device for advanced wastewater treatment. Background technique [0002] With the rapid development of modern industry, especially organic chemical industry, petrochemical industry, dyestuff, medicine, pesticide and other chemical industries, various refractory organic wastewaters are increasing. These wastewaters generally have high pollutant concentration, high toxicity and poor biodegradability. characteristics, seriously pollute the water environment and endanger human health. After conventional physicochemical and biochemical treatment, this type of industrial wastewater still contains a large amount of toxic and biorefractory organic pollutants, and further advanced treatment is required to meet discharge standards or reuse requirements. Therefore, the development of industrial wa...

AI Technical Summary

Problems solved by technology

According to the shape of the catalyst and the structure of the reactor, it can be divided into three types: coating catalyst photoreactor, filled photocatalytic reactor and suspended photocatalytic reactor. Among them, the suspended photocatalytic reactor has the highest photocatalytic efficiency, but the powder photocatalytic reactor Difficulty in catalyst recovery is the main problem of this reactor

In response to this problem, the Chinese patent (application number CN98111597.7) has developed an integrated method for photocatalysis and membrane separation. The catalyst is suspended in the photocatalytic reactor by dispersing air flow stirring and circulating water flow, and the reacted suspension passes through the membrane tube. The cross-flow method realizes solid-liquid separation, and the degradation wastewater permeates to the outside of the membrane tube to be discharged. The catalyst returns to the photocatalytic reactor with the reflux liquid to continue to participate in the reaction. However, this technology uses aeration to provide air, oxygen or ozone, and the utilization efficiency of the oxidant Low

Chinese patent (application number CN200610129881.2) proposes an integrated photocatalytic oxidation-membrane separation fluidized bed reaction device, which realizes the catalyst in the system through the design of an inverted Z-shaped deflector and three aeration zones. At the same time, the treated wastewater is discharged from the reaction system through a submerged membrane module. Aeration can cause the membrane filament to vibrate, and the concentrated water and catalyst return to the photocatalytic unit to continue the reaction, which effectively improves the mass transfer efficiency and light utilization rate. The hollow fiber organic membrane used in this technology has poor oxidation resistance and is not suitable for the reaction of adding ozone or hydrogen peroxide in the photocatalytic system

Chinese patent (application number CN201310122072.9) proposes a photocatalysis-membrane separation coupling process device and its operation method, which adopts the combination of flat membrane and photocatalysis. The flat membrane used in this technology is an organic membrane with poor oxidation resistance. Not suitable for the reaction of adding ozone or hydrogen peroxide in the photocatalytic system, and the membrane flux is low

[0006] Photocatalytic oxidation technology and membrane separation technology have their own advantages, but they also have shortcomings. The research on the existing technology is still in its infancy. How to better combine the advantages of the two to further improve the photocatalytic efficiency, A series of issues such as improving membrane flux and effectively slowing down membrane fouling still need further research

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