CN104399464B - A kind of photocatalyst for the activation of organochlorine inertia contaminant molecule in water treatment procedure and its preparation method and application - Google Patents

Abstract

The invention relates to a photocatalyst used for the activation of organic chlorine inert pollutant molecules in the water treatment process and its preparation method and application. The photocatalyst is composed of titanium dioxide, active aluminum oxide and copper oxide, and the titanium dioxide and copper oxide Evenly distributed on the surface of active aluminum oxide, the mass percentage of each component is: 6%-40% of titanium dioxide, 50%-92% of active aluminum oxide, and 2%-10% of copper oxide. The photocatalyst of the present invention has the advantages of uniform distribution of _TiO2 and controllable Cu species type, and exhibits high catalytic activity and selectivity in the process of selectively degrading DDT and HCH pollutants.

Description

A photocatalyst for activation of organic chlorine inert pollutant molecules in water treatment process and its preparation method and application

technical field

The invention relates to a photocatalyst for activating biologically inert pollutants in a water treatment process, a preparation method and an application thereof, which process organic chlorine inert pollutants that are difficult to biodegrade through a photocatalytic method, and belong to the technical field of water treatment.

Background technique

With the rapid development of modern agriculture and industry, water shortage and sewage treatment are facing severe challenges. Most of the river systems in various regions of our country are polluted. Water pollution makes the water quality of many cities inferior to Class IV. 50% of urban water supply sources cannot meet drinking water standards. The water quality of southern cities exceeds 60%. The water crisis has become a serious one. practical problems.

How to improve water quality and water treatment efficiency is an urgent problem in my country's water treatment industry. The deteriorating water quality has made the traditional water supply and drainage processes unable to do what they want, and the pollutants that are difficult to biodegrade are one of the main reasons. Pollutants continue to accumulate, putting enormous pressure on water supply and drainage plants. In response to this situation, a variety of new processes have emerged, the most representative ones are advanced oxidation technology and biological treatment technology. The former mainly oxidizes difficult-to-degrade pollutant molecules into small molecules or completely oxidizes them through strong oxidants (such as ozone, hydrogen peroxide or chlorine dioxide). Although this method is an effective way to solve refractory pollutants, there are toxic and harmful substances generated (such as high carcinogen chloroform) and the risk of regenerating small molecular compounds that are difficult to degrade. Biological treatment technology can effectively avoid secondary pollution caused by advanced oxidation. Organic pollutants can be effectively degraded through the action of microorganisms. The toxicity of biological metabolites is small or non-toxic, which greatly reduces the burden of subsequent water treatment and is conducive to the realization of organic pollution. Harmless disposal of materials. However, biological treatment technology also has its limitations, among which organic matter that is difficult to biodegrade restricts the promotion and application of biological treatment technology. In response to this situation, at present, new strains are often sought to meet the requirements of biodegradation of different organic pollutants. Although this method can play a role to a certain extent, the types of organic pollutants vary greatly, and new varieties are constantly introduced; And the process of cultivating new strains is long and the workload is large, which seems powerless to solve this problem. Another attractive method is to first change the molecular structure and molecular weight of biologically inert refractory organic pollutants, so that they can be biodegraded. The molecular changes in this method are different from advanced oxidation. The process It is controllable and selective, which can be called "biological activation of molecules".

Biologically inert pollutant molecules usually have the characteristics of strong molecular structure symmetry (such as HC6, benzene derivatives, etc.), high stability and large molecular weight, and it is usually difficult to change their molecular structure under mild conditions. However, with the help of Thanks to photocatalytic technology, this "molecular bioactivation" becomes possible. Through the design of the photocatalyst, its redox ability can be adjusted. The current literature has shown that its redox ability can change water into H ₂ and O ₂ , so it has the ability to change the structure of biologically inert molecules under mild conditions. And it can realize the controllability and selectivity of molecular structure change.

Titanium dioxide has long attracted the interest of many researchers due to its special physical and chemical properties, acid-base, semiconductor, photocatalysis and stability, and has been widely used in many fields; in the field of photocatalysis, titanium dioxide is the most researched Catalytic materials, the achievements of TiO ₂ photocatalytic hydrogen production have already been reported in the literature. Because TiO ₂ has a wide band gap, high vacuum potential, and strong redox ability, and its redox ability and absorption spectrum band can be changed by means of doping, sensitization, etc., there is a large room for adjustment, so _TiO2 is an ideal material for photocatalytic activation of inert biomolecules.

However, most of the currently used titanium dioxide photocatalysts are made of pure titanium dioxide, which not only has a small specific surface area and poor strength, but also is unsatisfactory in terms of selectivity and catalytic activity.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention provides a photocatalyst for activating organic chlorine inert pollutant molecules in the water treatment process, its preparation method and application.

The invention utilizes the photocatalyst to activate the biological inert pollutants in the water treatment process, especially the organic chlorine inert pollutants, so as to facilitate the utilization and metabolism of microorganisms.

Technical scheme of the present invention is as follows:

A photocatalyst for the activation of organic chlorine inert pollutant molecules in the water treatment process. It is composed of titanium dioxide, active aluminum oxide and copper oxide. Titanium dioxide and copper oxide are evenly distributed on the surface of active aluminum oxide. Each component The mass percent content is: 6%-40% of titanium dioxide, 50%-92% of activated aluminum oxide, and 2%-10% of copper oxide.

According to the present invention, preferably, the mass percent content of each component of the photocatalyst is: 20%-35% of titanium dioxide, 55%-75% of activated aluminum oxide, and 5%-10% of copper oxide.

According to the present invention, preferably, the active aluminum oxide is γ-Al ₂ O ₃ , the titanium dioxide is anatase titanium dioxide, and the copper oxide is CuO and Cu ₂ O, more preferably Yes, the mass ratio of CuO and Cu ₂ O is 1:(0.02-0.1).

According to the present invention, the preparation method of above-mentioned photocatalyst, the steps are as follows:

(1) Add γ-Al ₂ O ₃ to the mixed aqueous solution composed of soluble copper salt, EDTA·4Na and pyridine and immerse for 12h; ~110℃ drying for 10~15h;

The mass ratio of the γ-Al ₂ O ₃ to the copper element in the soluble copper salt is (50-92): (2-10), and the concentration of the soluble copper salt in the mixed aqueous solution is 2-16 wt%. The concentration of the EDTA·4Na is 2-2.5wt%, and the concentration of the pyridine is 2-2.5wt%;

( ₂ ) dissolving orthotitanic acid in a hydrogen peroxide solution with a concentration of 20 to 30 wt%, and mixing uniformly to obtain a hydrogen peroxide solution of orthotitanic acid; The mass ratio of _O3 is (6～40): (50～92);

(3) Soak the dried solid in step (1) in an orthotitanic acid hydrogen peroxide solution for 10 to 15 hours, filter, and dry the solid at 100 to 110° C. for 10 to 15 hours;

(4) heating the dried solid in step (3) to 450-550° C. at a heating rate of 10-18° C./min, keeping the temperature constant for 3-6 hours, and then cooling down to room temperature;

(5) Add the sample obtained in step (4) into 10-20wt% formaldehyde solution, soak for 10-15 hours, and vacuum-dry at 50-70° C. for 10-15 hours to obtain the photocatalyst.

According to the present invention, preferably, the mass ratio of the γ-Al ₂ O ₃ described in step (1) to the copper element in the soluble copper salt is (55-75): (5-10), and in the mixed aqueous solution The concentration of soluble copper salt is 3-8wt%;

The soluble copper salt is copper nitrate, copper sulfate, copper acetate or/and copper chloride, more preferably copper nitrate.

According to the present invention, preferably, the amount of orthotitanic acid used in step (2) is calculated as titanium dioxide, and the mass ratio of γ-Al ₂ O ₃ in step (1) is (20-35): (55-75).

According to the present invention, preferably, the heating rate in step (4) is 15-18°C/min, and the temperature is raised to 480-520°C.

According to the present invention, preferably, the concentration of the formaldehyde solution described in step (5) is 15wt%.

According to the present invention, the γ-Al ₂ O ₃ described in step (1) can be available on the market; the active γ-Al ₂ O ₃ produced by the industrial aluminum hydroxide high-temperature rapid dehydration process can also be made into spherical or Bar type, preferably spherical. All get final product according to prior art.

According to the present invention, the orthotitanic acid used in step (2) can be available on the market; it can also be reacted with metatitanic acid and concentrated sodium hydroxide solution at 100°C for three hours to convert it into sodium orthotitanate, which can be washed with water to obtain orthotitanate. Titanic acid: metatitanic acid can be produced by industrial sulfuric acid method or by industrial chlorination method, preferably the metatitanic acid produced by industrial sulfuric acid method. All get final product according to prior art.

According to the present invention, the above-mentioned photocatalyst is used for activating and degrading organic chlorine inert pollutants in sewage, especially for activating and degrading di-p-chlorophenyltrichloroethane (DDT) and hexachlorocyclohexane in sewage. Alkanes) and other organic chlorine inert pollutants have a better effect.

According to the present invention, the concrete application steps of above-mentioned photocatalyst are as follows:

The photocatalyst is pulverized, loaded into a photocatalytic reactor, and the sewage of organic chlorine inert pollutants is passed through, and the photocatalyst is reacted under normal temperature and normal pressure.

According to the present invention, preferably, the photocatalyst is crushed to 20-40 meshes, the mass-volume ratio of photocatalyst to sewage is 1:150g/ml, the wavelength of light is 370-420nm, and the reaction time of light is 1-420nm. 3h.

Principle of the present invention:

In the preparation process of the photocatalyst of the present invention, orthotitanic acid is used as a precursor, hydrogen peroxide is used as a solvent, and after the orthotitanic acid is dissolved, active aluminum oxide loaded with copper oxide is impregnated. This catalyst uses _TiO2 as the main catalyst to generate photogenerated electron-holes, which can be highly dispersed _on the surface of _Al2O3 through the method of the present invention. On the one hand, the utilization rate of _TiO2 is increased, and on the other hand, the existence of copper species can The probability of electron-hole recombination is reduced and the redox ability is regulated, so that the reactivity and selectivity are greatly improved. In order to improve the effective dispersion of copper oxide in the preparation process, EDTA·4Na was used as a complexing agent, pyridine was used as a stabilizer, and formaldehyde was used as a reducing agent to control the proportion of copper species.

The photocatalyst of the invention is suitable for the selective degradation of organic chlorine inert pollutants in water, and the degradation products are easily metabolized by biomolecules into harmless products. The organochlorine molecules that are difficult to degrade generally have the characteristics of strong molecular symmetry, stable structure, and large molecules. By selectively degrading these organochlorine molecules, the symmetry of the molecules can be broken, the molecular scale can be reduced, and it has a certain degree of hydrophilicity. , so that these molecules can easily enter the bacterial cells and be degraded.

The beneficial effects of the present invention are as follows:

1. The photocatalyst of the present invention has the advantages of uniform distribution of _TiO and controllable Cu species type, and is effective in selective degradation of bis-p-chlorophenyltrichloroethane (DDT for short) and hexahexa (hexachlorocyclohexane) pollution exhibited high catalytic activity and selectivity.

2. The photocatalyst of the present invention overcomes the disadvantages of small specific surface area and poor strength of the pure _TiO2 catalyst at the same time, and has high catalytic activity.

3. The raw materials for the preparation of the photocatalyst of the present invention come from a wide range of sources, are cheap and easy to obtain, and have a simple preparation method.

Description of drawings

Figure 1 is a high-resolution electron micrograph of the catalyst prepared in Example 1 of the present invention.

detailed description

The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings, but is not limited thereto.

The raw materials used in the examples are conventional commercially available products.

Wherein, orthotitanic acid is prepared by the following method:

The metatitanic acid prepared by the sulfuric acid method was dried at 110°C×12h and then added to the NaOH solution (TiO ₂ content: NaOH content = 1:3) to react to form sodium orthotitanate, which was washed with deionized water Hydrolyzed to generate ortho-titanic acid, vacuum-dried at room temperature, that is.

In the examples, the heating rate during the calcination process is 15° C./min.

Example 1:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 1g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA·4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 5g of orthotitanic acid (3.45g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105℃×12h; after calcination at 500℃ for 4h ;

The obtained sample was added into 20ml of 15w% formaldehyde solution, soaked for 12 hours, and vacuum-dried at 60°C for 12 hours to obtain sample A.

In this example, the mass percentages of the components of the sample A photocatalyst were: 25% titanium dioxide, 72.5% active aluminum oxide, and 2.5% copper oxide. The high-resolution electron micrograph of the photocatalyst is shown in Figure 1. It can be seen from Figure 1 that the distribution of TiO ₂ is highly dispersed and uniform.

Example 2:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 1g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA·4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 3g of orthotitanic acid (2.1g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105°C for 12h, and bake at 500°C for 4h;

The obtained sample was added into 20ml of 15wt% formaldehyde solution, soaked for 12h, and vacuum dried at 60°C for 12h to obtain sample B.

The weight percentage of each component of sample B photocatalyst obtained in this embodiment is: titanium dioxide 16.9%, active aluminum oxide 80.4%, copper oxide 2.7%.

Example 3:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 1g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA·4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 1 g of orthotitanic acid (0.69 g as TiO ₂ ), add 40 ml of hydrogen peroxide to dissolve it, and then immerse the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12 h, then dry at 105°C for 12 h, and bake at 500°C for 4 h;

The obtained sample was added into 20ml of 15wt% formaldehyde solution, soaked for 12h, and vacuum dried at 60°C for 12h to obtain sample C.

The mass percent content of each component of the sample C photocatalyst obtained in this embodiment is: 6.2% of titanium dioxide, 90.7% of activated aluminum oxide, and 3.1% of copper oxide.

Example 4:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 1g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA·4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 7g of orthotitanic acid (4.8g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105°C for 12h, and bake at 500°C for 4h;

The obtained sample was added to 20ml of 15wt% formaldehyde solution, soaked for 12 hours, and vacuum dried at 60°C for 12 hours to obtain sample D.

The mass percent content of each component of the sample D photocatalyst obtained in this embodiment is: 31.7% of titanium dioxide, 66.1% of active aluminum oxide, and 2.2% of copper oxide.

Example 5:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 1g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA·4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 9g of orthotitanic acid (6.2g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105°C for 12h, and bake at 500°C for 4h;

The obtained sample was added into 20ml of 15wt% formaldehyde solution, soaked for 12h, and vacuum dried at 60°C for 12h to obtain sample E.

The mass percent content of each component of the sample E photocatalyst obtained in this embodiment is: 37.4% of titanium dioxide, 60.5% of active aluminum oxide, and 2.1% of copper oxide.

Embodiment 6:

Weigh 40-60 mesh γ-Al ₂ O ₃ 10g, weigh anhydrous copper nitrate 2g, pyridine 1ml, dissolve EDTA·4Na1g in 40ml water, impregnate γ-Al ₂ O ₃ for 12h, after the impregnation is completed, and Dry at ℃ for 12 hours;

Weigh 7g of orthotitanic acid (4.8g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105°C for 12h, and bake at 500°C for 4h;

The obtained sample was added to 20ml of 15wt% formaldehyde solution, soaked for 12h, and vacuum dried at 60°C for 12h to obtain sample G.

The mass percent content of each component of the sample F photocatalyst obtained in this embodiment is: 31% of titanium dioxide, 64.6% of activated aluminum oxide, and 4.4% of copper oxide.

Embodiment 7:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 3g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA 4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 7g of orthotitanic acid (4.8g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105°C for 12h, and bake at 500°C for 4h;

The obtained sample was added into 20ml of 15wt% formaldehyde solution, soaked for 12h, and vacuum dried at 60°C for 12h to obtain sample H.

The mass percent content of each component of the sample G photocatalyst obtained in this embodiment is: 30.4% of titanium dioxide, 63.2% of active aluminum oxide, and 6.4% of copper oxide.

Embodiment 8:

Weigh 10g of 40-60 mesh γ-Al ₂ O ₃ , weigh 4g of anhydrous copper nitrate, 1ml of pyridine, dissolve 1g of EDTA 4Na in 40ml of water, and impregnate γ-Al ₂ O ₃ for 12h. Dry at ℃ for 12 hours;

Weigh 7g of orthotitanic acid (4.8g as TiO ₂ ), add 40ml of hydrogen peroxide to dissolve, impregnate the above-mentioned γ-Al ₂ O ₃ treated with copper at room temperature for 12h, then dry at 105°C for 12h, and bake at 500°C for 4h;

The obtained sample was added to 20ml of 15wt% formaldehyde solution, soaked for 12h, and dried in vacuum at 60°C for 12h to obtain sample I.

The mass percent content of each component of sample H photocatalyst obtained in this embodiment is: 29.7% of titanium dioxide, 61.9% of activated aluminum oxide, and 8.4% of copper oxide.

Application example

The photocatalysts prepared in Examples 1-8 are used to treat DDT simulated polluted wastewater, and the steps are as follows:

Put 2 g of photocatalyst samples crushed into 20-40 meshes into an internally illuminated photocatalytic reactor with a volume of 500 ml, add 300 ml of reaction liquid (composed of water and DDT, DDT concentration 100 mg/kg), and react at normal temperature and pressure 2h; use a 500W high-pressure mercury lamp as the light source.

Agilent 6890N gas chromatography was used to measure the content of DDT in the treated reaction liquid; ECD detector was used to measure DDT with a special packed column, the column temperature was 200°C, and high-purity nitrogen was used as the carrier gas.

In this application example, DDT→PCPA is used as the index reaction to investigate the catalytic activity and selectivity of photocatalyst samples. The catalytic activity is characterized by the conversion rate of DDT. The higher the conversion rate, the higher the catalytic activity.

The initial concentration of DDT is 100mg/kg, and the reaction formula is as follows:

Calculate the conversion rate (η _DDT ) of DDT and the selectivity (S _PCPA ) of PCPA according to the following formula:

η _DDT ＝(M ₀ -M ₁ )/M0╳100％

S _PCPA ＝M _C '/(M ₀ -M ₁ )╳100％

Among them, M ₀ and M ₁ represent the concentration of DDT in the initial and final reaction solution respectively, and M _C' is the amount of DDT converted into PCPA.

The reactivity and selectivity evaluation results of the photocatalyst samples A to H prepared in Examples 1 to 8 are shown in Table 1, where the activity data is the data of the 2h reaction, and the selectivity is calculated based on the 2h reaction data.

Table 1. Activity and selectivity comparison of different photocatalyst samples

Photocatalyst sample A B C D. E. f G h DDT conversion rate 78 80 82 87 90 86 88 87 PCPA optional 83 82 83 82 83 93 93 94

It can be seen from Table 1 that the photocatalyst of the present invention has good reactivity and selectivity in treating DDT organochlorine pollutants.

Claims (9)

1. the photocatalyst for the activation of organochlorine inertia contaminant molecule in water treatment procedure, it is characterized in that, this photocatalyst is made up of titanium dioxide, active aluminium sesquioxide and copper oxide, titanium dioxide and copper oxide are evenly distributed on active aluminium sesquioxide surface, each composition quality percentage composition is: titanium dioxide 6% ~ 40%, active aluminium sesquioxide 50% ~ 92%, copper oxide 2% ~ 10%; Described copper oxide is CuO and Cu₂O form, described active aluminium sesquioxide is ��-Al₂O₃, described titanium dioxide is Detitanium-ore-type titanium dioxide, described CuO and Cu₂The mass ratio of O is 1:(0.02 ~ 0.1).

2. the photocatalyst for the activation of organochlorine inertia contaminant molecule in water treatment procedure according to claim 1, it is characterized in that, the each composition quality percentage composition of described photocatalyst is: titanium dioxide 20% ~ 35%, active aluminium sesquioxide 55% ~ 75%, copper oxide 5% ~ 10%.

3. a preparation method for photocatalyst described in the arbitrary item of claim 1 ~ 2, step is as follows:

(1) by ��-Al₂O₃Join in the mixed aqueous solution being made up of soluble copper salt, EDTA 4Na and pyridine and flood 12h; After having flooded, it is neutral by deionized water wash solid to washing lotion, and dries 10 ~ 15h in 100 ~ 110 DEG C;

Described ��-Al₂O₃Being (50 ~ 92) with the mass ratio of copper in soluble copper salt: (2 ~ 10), in described mixed aqueous solution, the concentration of soluble copper salt is 2 ~ 16wt%, and the concentration of described EDTA 4Na is 2 ~ 2.5wt%, and the concentration of described pyridine is 2 ~ 2.5wt%;

(2) positive metatitanic acid is dissolved in hydrogen peroxide solution that concentration is 20 ~ 30wt%, mixes, obtain the hydrogen peroxide solution of positive metatitanic acid;The consumption of positive metatitanic acid in titanium dioxide, with ��-Al in step (1)₂O₃Mass ratio be (6 ~ 40): (50 ~ 92);

(3) the solid impregnating 10 ~ 15h in the hydrogen peroxide solution of positive metatitanic acid after step (1) being dried, filters, and solid dries 10 ~ 15h at 100 ~ 110 DEG C;

(4) with the temperature rise rate of 10-18 DEG C/min, the solid after oven dry in step (3) being warming up to 450 ~ 550 DEG C, constant temperature 3-6 hour, is down to room temperature;

(5) being joined by the sample of gained in step (4) and flood 10 ~ 15h in the formaldehyde solution of 10 ~ 20wt%, 50 ~ 70 DEG C of vacuum-drying 10 ~ 15h, obtain photocatalyst.

4. preparation method according to claim 3, it is characterised in that, described soluble copper salt is that cupric nitrate, copper sulfate, neutralized verdigris are or/and cupric chloride.

5. preparation method according to claim 3, it is characterised in that, the temperature rise rate described in step (4) is 15 ~ 18 DEG C/min, is warming up to 480 ~ 520 DEG C.

6. the application of photocatalyst described in the arbitrary item of claim 1 ~ 2, it is characterised in that, it is applied to organochlorine inertia pollutent in activation degradation of sewage.

7. application according to claim 6, it is characterised in that, described organochlorine inertia pollutent is DDT and phenyl-hexachloride.

8. application according to claim 6, it is characterised in that, embody rule step is as follows:

Photocatalyst is pulverized, loads in photo catalysis reactor, lead to the sewage into organochlorine inertia pollutent, illumination reaction under normal temperature, normal pressure.

9. application according to claim 8, it is characterised in that, described photocatalyst is crushed to 20 ~ 40 orders, and the mass volume ratio of photocatalyst and sewage is 1:150g/ml, and described illumination wavelength is 370 ~ 420nm, and the illumination reaction time is 1 ~ 3h.