CN102166471B - An Integrated Flue Gas Purification System Based on Heterogeneous Photo-Fenton - Google Patents

Abstract

The invention discloses a heterogeneous-Photo-Fenton-based integrated smoke gas purification system. The smoke gas purification system generates a hydroxyl radical (.OH) with strong oxidizability by using heterogeneous Photo-Fenton to oxidize SO2, NO and Hg0 in the smoke gas into H2SO4, HNO3 and Hg2<+> respectively, wherein the H2SO4, the HNO3 and the Hg2<+> are fixed in solution; after reaction, a solid catalyst in mixed solution can be recycled through simple primary precipitation separation; a small amount of Hg2<+> in the solution can be generated into insoluble HgS by adding the same mole ratio of S2<->, and then the HgS is recycled through secondary precipitation separation; and the remaining sulfuric acid and nitric acid solution can be used as an industrial raw material to be further recycled. The whole integrated desulfuration, denitration and demercuration processes generate no secondary pollution, so the heterogeneous-Photo-Fenton-based integrated smoke gas purification system has a very good application prospect.

Description

An Integrated Flue Gas Purification System Based on Heterogeneous Photo-Fenton

technical field

The invention relates to the control of flue gas emission pollutants in the combustion process, in particular to an integrated flue gas purification system based on heterogeneous Photo-Fenton.

Background technique

Sulfur oxides, nitrogen oxides, and mercury produced during combustion can cause serious hazards such as acid rain, photochemical smog, and carcinogenicity and teratogenicity. Therefore, developing effective methods for flue gas desulfurization, denitrification and mercury removal is one of the important tasks of environmental protection scientists and technicians in various countries. In recent years, although people have developed a large number of flue gas desulfurization, denitrification and demercury technologies, due to the limitations of human understanding and the gradual development of science and technology, the existing desulfurization, denitration and demercury technologies were only developed for a single Pollutants are the removal target, and it is generally impossible to simultaneously remove multiple pollutants from the flue gas. For example, the flue gas desulfurization and denitrification technologies that are widely used at present are mainly wet limestone-gypsum flue gas desulfurization technology (Ca-WFGD) and ammonia selective catalytic reduction (NH ₃ -SCR). Separate desulfurization and denitrification, but can not achieve simultaneous removal in one reactor. Although the joint and superimposed use of the two processes can achieve simultaneous desulfurization and denitrification, it also causes the entire system to be complex, occupy a large area, and have high investment and operating costs. In addition, with the continuous improvement of human requirements for environmental protection, laws and regulations for the control of mercury emissions in flue gas have gradually been introduced, but there is no economical and effective flue gas mercury removal technology that has achieved large-scale commercial application. If a separate flue gas mercury removal system is added at the end of the existing Ca-WFGD and NH ₃ -SCR desulfurization and denitrification systems, it will inevitably cause a further sharp increase in the initial investment and operating costs of the entire system, and it will eventually be difficult to implement in developing countries. Get large-scale commercial applications.

To sum up, if sulfur oxides, nitrogen oxides, and mercury can be removed simultaneously in one reactor, the complexity and footprint of the system can be greatly reduced, thereby reducing the initial investment and operating costs of the system. Wet flue gas purification technology is a traditional flue gas treatment technology. It has the characteristics of small initial investment, simple process flow and easy removal of multiple pollutants at the same time. It is a very promising flue gas purification technology for development and application. , but the research progress of traditional wet flue gas purification technology has been relatively slow, the main reason is that nitrogen oxides and mercury elements contain more than 90% insoluble NO and 40-80% insoluble Hg ⁰ . According to the double-membrane theory, gas-phase molecules must first dissolve into the liquid phase through mass transfer and diffusion processes from the gas state, and then they can undergo chemical reactions and be fixed in the absorption liquid. The insoluble characteristics of NO and Hg ⁰ make its absorption in the liquid phase difficult. The mass transfer resistance is greatly increased, and it is difficult to significantly increase the solubility of NO and Hg ⁰ in the liquid phase only by adjusting the pH and temperature of the absorbing liquid. The low efficiency of denitrification and mercury removal makes it impossible to achieve real simultaneous desulfurization, denitrification and mercury removal. Therefore, it is one of the keys to solve this problem to find an effective method that can quickly convert NO and Hg ⁰ into easily soluble forms.

Contents of the invention

The invention discloses an integrated flue gas purification system based on heterogeneous Photo-Fenton, which uses heterogeneous Photo-Fenton (ultraviolet light, hydrogen peroxide, solid catalyst advanced oxidation process) to generate hydroxyl radicals with strong oxidative properties (·OH), oxidize SO ₂ , NO _x and Hg ⁰ in the flue gas to H ₂ SO ₄ , HNO ₃ and Hg ²⁺ respectively and fix them in the solution. After the reaction, the solid catalyst in the solution can be separated by simple precipitation Afterwards, recycling and recycling can be realized. The Hg ²⁺ in the solution can be regenerated by adding divalent sulfide ions S ^2- in an equimolar ratio to generate insoluble HgS, which can then be recycled after precipitation and separation, while the remaining sulfuric acid and nitric acid solutions can be used as Industrial raw materials are further recycled, and the entire integrated desulfurization, denitrification and mercury removal process has no secondary pollution. It is a very promising flue gas purification technology.

In order to achieve the above object, the embodiment adopted in the present invention is: a kind of integrated flue gas purification system based on heterogeneous Photo-Fenton, it is characterized in that: be provided with burner, heat exchanger, bubble tower, liquid addition tower Combustion and emission system composed of two-stage separation tower, regeneration tower, induced draft fan and chimney. The flue gas including SO ₂ , NO _x and Hg ⁰ produced by the combustion of the burner is cooled by the heat exchanger and then installed from the bottom of the bubble tower. The nozzle of the nozzle leads into the bubble tower, and the heterogeneous Fenton reagent containing hydrogen peroxide and solid catalyst is added to the liquid addition tower, and then the first circulation pump is also passed into the bubble tower from the upper part of the bubble tower, and an ultraviolet lamp is arranged in the bubble tower tube, flue gas and heterogeneous Fenton reagent produce a gas-liquid absorption reaction in the bubble column, and ultraviolet light stimulates and decomposes heterogeneous Fenton reagent to release hydroxyl radicals (OH) with strong oxidative properties, and SO in the flue gas _2. NO _x and Hg ⁰ are oxidized to H ₂ SO ₄ , HNO ₃ and Hg ²⁺ and fixed in the solution, 20-40% of the mixed solution is pumped into the liquid addition tower by the second circulation pump for recycling, and the remaining The mixed solution is pumped into the first-stage separation tower by the third circulation pump for precipitation and separation, and then sent to the regeneration tower by the fourth circulation pump. After the solid catalyst in the mixed solution is regenerated, it is passed into the liquid addition tower by the fifth circulation pump for recycling; The Hg ²⁺ -containing solution after the primary separation is pumped into the secondary separation tower by the sixth circulating pump, and the insoluble HgS is generated by adding equimolar ratio of divalent sulfide ions S ^2- to the secondary separation tower, which is separated by precipitation. Finally, the recycling of mercury sulfide is realized, and the remaining high-concentration sulfuric acid and nitric acid solutions are recycled as industrial raw materials. The washed flue gas is drawn from the top of the bubble tower through the induced draft fan into the chimney for discharge.

The ultraviolet lamp is perpendicular ^to the bottom of the bubble tower, and the ultraviolet radiation power per unit volume in the bubble tower is 5W/m ³ -200W/m ³ . The ultraviolet radiation power required per unit volume when the tower is empty, and the wavelength of ultraviolet light is 120nm-360nm. When setting multiple ultraviolet lamp tubes, the multiple ultraviolet lamp tubes are arranged in concentric circles, and the distance between adjacent concentric circles is the same. Multiple ultraviolet lamp tubes are evenly distributed on the circumference of different diameters, set along the same diameter line, and each adjacent The central angle between the two diameter lines is the same, and the center of the circle is equipped with an ultraviolet lamp; the nozzles are arranged on the concentric circle alternately spaced from the concentric circle of the ultraviolet lamp, and placed on the diameter line of the half angle of the central angle of the two ultraviolet lamps ,

The solid catalyst is one of Fe ₂ O ₃ , MnO ₂ , CuO or TiO ₂ . The solid catalyst is activated and regenerated by high-temperature calcination in the regeneration tower. The calcination temperature is within the range of 300°C-600°C. The mass concentration is in the range of 0.5g/L-5.0g/L, the particle size of the solid catalyst is between 80 mesh and 200 mesh, and the molar concentration of hydrogen peroxide added is in the range of 0.1mol/L-2.5mol/L.

The flue gas temperature at the bubble column inlet is 15°C-75°C, the liquid-gas ratio is 5L/m ³ -50L/m ³ , and the residence time of the flue gas flowing through the bubble column reactor is 0.5s-20s.

The molar amount of divalent sulfide ion S ^2- added in the secondary separation tower is equal to the molar amount of Hg ²⁺ in the solution, that is, n(S ^2- ):n(Hg ²⁺ )=1:1.

System reaction process of the present invention:

1. The heterogeneous Photo-Fenton advanced oxidation process releases strong oxidizing hydroxyl radicals (OH):

Fe ²⁺ -S+H ₂ O ₂ -S→Fe ³⁺ -S+ OH-S+OH ^- -S (1)

Fe ³⁺ -S+H ₂ O ₂ -S→Fe ³⁺ (HO ₂ ) ²⁺ -S+H ⁺ -S (2)

FeOH ²⁺ -S+H ₂ O ₂ -S→Fe ³⁺ (OH)(HO ₂ ) ⁺ -S+H ⁺ -S (3)

Fe ³⁺ (HO ₂ ) ²⁺ -S+hv-S→Fe ²⁺ -S+·HO ₂ -S (4)

Fe ³⁺ (OH)(HO ₂ ) ⁺ -S+hv-S→Fe ²⁺ -S+·HO ₂ -S+OH ^- -S (5)

2. SO ₂ , NO _x and Hg ⁰ in the flue gas emitted by the burner are oxidized by hydroxyl radicals (·OH) to form a mixed solution of H ₂ SO ₄ , HNO ₃ and Hg ²⁺ :

NO-S+·OH-S→HNO ₂ -S (6)

NO ₂ -S+·OH-S→HNO ₃ -S (7)

SO ₂ -S+·OH-S→HSO ₃ -S (8)

HSO ₃ -S+·OH-S→H ₂ SO ₄ -S (9)

Hg ⁰ -S+ OH-S→HgO-S+ HS (10)

Hg ⁰ -S+·OH-S→Hg(OH) ₂ -S (11)

3. After precipitation and separation in the primary separation tower, the solid catalyst can be sent to the regeneration tower for activation and regeneration, and then recycled;

4. The Hg ²⁺ produced by the reaction can be absorbed by the added S ²⁺ and react to form an insoluble HgS precipitate, which is then recycled after precipitation and separation:

Hg ²⁺ +S ^2- →HgS↓ (12)

5. After the heavy metal mercury is captured and recovered, only the mixed solution of sulfuric acid and nitric acid with high concentration remains in the solution, which can be recycled as industrial raw materials, and the whole integrated desulfurization, denitrification and demercuration process has no secondary pollution.

Advantages and remarkable effects of the present invention: the heterogeneous Photo-Fenton advanced oxidation process can release hydroxyl radicals (OH) with extremely strong oxidation ability, and the reaction rate constant between OH and most organic matter is as high as 10 ⁶ -10 ¹⁰ mol/L s, can easily attack various pollutants and degrade them into harmless products, and the solid catalyst in the reaction process is easy to separate and regenerate and recycle. advanced oxidation removal process. Compared with the applicant (a simultaneous desulfurization and denitrification system based on photochemical advanced oxidation: 201012096592.5) and (a flue gas mercury removal system based on photochemical advanced oxidation: 201012096592.8), the present invention has the following obvious advantages:

(1) With the continuous improvement of people's requirements for environmental protection, laws and regulations for the control of mercury emissions in flue gas are also gradually introduced. The simultaneous removal of pollutants can further reduce the initial investment and operating costs of the system. With the continuous improvement of human requirements for environmental protection, this advantage of the present invention will be gradually highlighted, and both 201012096592.5 and 201012096592.8 cannot simultaneously remove three kinds of pollutants in the same reactor.

(2) The present invention can further improve the removal efficiency of pollutants by adding a recyclable high-efficiency solid catalyst, and can also greatly reduce the dosage of hydrogen peroxide under the same conditions, thereby greatly reducing the use cost of hydrogen peroxide. In addition, the solid catalyst in the present invention can be regenerated and recycled after simple precipitation and separation, and there is no secondary pollution in the whole removal process, so it is a new flue gas purification technology with very promising application prospects.

Description of drawings

Fig. 1 is a flow chart of the system of the present invention;

Fig. 2 is an installation layout diagram of nozzles and ultraviolet lamps in the bubbling bed of the system of the present invention.

Detailed ways

Referring to Figures 1 and 2, the flue gas from the burner (boiler) 1 containing a certain concentration of SO ₂ , NO _x and Hg ⁰ is first cooled to a suitable temperature through a heat exchanger, and then passed through the nozzle 3 at the bottom of the bubbling bed 4 Enter the liquid phase reaction zone to participate in the gas-liquid absorption reaction; the heterogeneous Fenton reagent is first added to the liquid addition tower 12, and then added to the liquid phase reaction zone in the bubble bed 4 from the top of the bubble tower 4 by the first circulation pump 7 to participate in the gas liquid absorption reaction; the ultraviolet lamp 6 covered with the quartz sleeve 5 excites and decomposes the heterogeneous Fenton reagent to release the strong oxidizing hydroxyl radical OH, and rapidly oxidizes SO ₂ , NO _x and Hg ⁰ in the flue gas respectively It is H ₂ SO ₄ , HNO ₃ and Hg ²⁺ solutions; in order to prepare high-concentration sulfuric acid and nitric acid solutions and reduce the processing cost of liquid phase products, part of the mixed solution generated by the reaction needs to be pumped into the liquid by the second circulation pump 8 The tower 12 is recycled, and the remaining mixed solution is pumped into the primary separation tower 10 by the third circulation pump 9, and the solid catalyst is sent to the regeneration tower 14 by the fourth circulation pump 11 after simple precipitation and separation in the primary separation tower 10 To achieve regeneration and activation, the regenerated solid catalyst is passed into the liquid addition tower 12 by the fifth circulation pump 13 for recycling; the Hg2 ⁺ -containing solution after the primary separation is pumped into the secondary separation tower by the sixth circulation pump 15 16, and then by adding equimolar ratio of divalent sulfide ion S ^2- reaction to generate insoluble HgS, after precipitation and separation, the recovery of mercury element mercuric sulfide is realized, and the remaining high-concentration sulfuric acid and nitric acid solution can be used as industrial Recycling of raw materials; the washed flue gas is drawn from the top of the bubble tower 4 into the chimney 18 by the induced draft fan 17 and then discharged into the atmosphere.

In the above system:

Due to the high temperature of the flue gas, if the high-temperature flue gas is directly passed into the liquid-phase reaction zone of the bubble column, the solubility of the gas-phase pollutants will decrease, resulting in a decrease in the removal efficiency of the target pollutants. In addition, high temperature will also cause hydrogen peroxide to be directly decomposed into oxygen, and the utilization rate will decrease. Therefore, before the flue gas is passed into the bubble tower, the high-temperature flue gas needs to be effectively cooled by a heat exchanger, so the temperature of the flue gas at the inlet of the bubble tower should generally be controlled between 15-75°C.

Since the flue gas contains fine particles, if the ultraviolet lamp is directly exposed to the flue gas, the ultraviolet lamp is easily damaged by the high-speed erosion of the particles. Therefore, the outer surface of the ultraviolet lamp needs to be covered with a quartz sleeve made of high-transmittance quartz material. The inner diameter of the quartz sleeve needs to be 2-4mm larger than the outer diameter of the ultraviolet lamp, and the length is equal or similar to that of the ultraviolet lamp. . In order to maximize the use of light energy and increase the intensity of ultraviolet radiation, the ultraviolet lamps in the reactor must be kept perpendicular to the bottom of the bubble tower when installed. In addition, in order to maintain uniform ultraviolet radiation in the reactor and increase the effective utilization of light energy, the distance b between the ultraviolet lamps must be kept equal, and the central angle a must also be kept equal. At the same time, if the arrangement density of ultraviolet lamps in the reactor is too large, the flow resistance of the flue gas in the reactor will increase, resulting in an increase in the operating load and energy consumption of the system, but if the arrangement density of ultraviolet lamps in the reactor is too small, It is difficult to achieve sufficient light radiation intensity, resulting in pollutant removal indicators that do not meet environmental protection requirements. Therefore, the optimal ranges of the ultraviolet lamp spacing b and the central angle a are generally 2cm-30cm and 10-40 degrees, respectively. The irradiation intensity of the ultraviolet lamp is related to the size of the photon quantum yield or the yield of hydroxyl radical · OH. If the UV radiation intensity is too low, it will be difficult to fully stimulate the ozone decomposition to generate a sufficient number of hydroxyl radicals. OH oxidation removes pollutants, but if the UV radiation intensity is too high, the energy consumption of the system will increase significantly. Therefore, the ultraviolet light intensity needs to be kept at 5W/m ³ -200W/m ³ , where the unit W/m ³ refers to the ultraviolet radiation power required per unit volume when the reactor is empty before the reactor is installed with an ultraviolet lamp . When the wavelength of ultraviolet light is short, the photon excitation energy of ultraviolet light is relatively increased, but at this time the propagation distance of ultraviolet light is relatively short, which shows that the pollutant treatment capacity of unit power ultraviolet light is low. When the wavelength of ultraviolet light is longer, although the propagation distance of ultraviolet light will increase, the excitation energy of ultraviolet light photons will be significantly reduced at this time, resulting in the decomposition of heterogeneous Fenton reagent by ultraviolet light photons to release the energy of hydroxyl radical OH Insufficient, eventually leading to the removal efficiency of pollutants is difficult to meet environmental protection requirements. Therefore, the effective wavelength of ultraviolet light should be kept in the range of 160nm-360nm.

The effective mass concentration of the solid catalyst should be kept in the range of 0.5g/L-5.0g/L, while the effective molar concentration of hydrogen peroxide should be kept in the range of 0.1mol/L-2.5mol/L. If the dosage is too high, it will lead to an increase in the application cost, otherwise, the removal efficiency of pollutants will be difficult to meet the requirements. In addition, there are also strict requirements on the particle size of the solid catalyst to be added. If the particle size is too large, the specific surface area of the catalyst will decrease, but if the particle size of the solid catalyst is too small, it will bring great difficulties to the primary precipitation separation. Big difficulty, increase post-processing cost. Therefore, the particle size of the solid catalyst should generally be kept between 80 mesh and 200 mesh.

The amount of divalent sulfide ion S ^2- added in the gas-liquid absorption tower needs to be strictly controlled. If S ^2- is added excessively, it will cause secondary pollution and increase the application cost, but if the amount of S ^2- added is too small, the It will lead to insufficient chemical absorption process in the secondary separation tower, and the capture rate of Hg ²⁺ is low. Therefore, in practical applications, the molar amount of added S ^2- should be kept equal to the molar amount of Hg ²⁺ in the solution, that is, n(S ^2- ):n(Hg ²⁺ )=1:1 should be kept.

Due to the separation and recovery of the liquid-phase mixed product, secondary treatment is required. Therefore, if the concentration of the mixed solution is too dilute, it will inevitably increase the cost of secondary treatment. Therefore, the entire removal system needs to be equipped with a partial solution recirculation system, that is, generally 20-40% of the mixed solution produced after the reaction needs to be re-pumped into the liquid addition tower for recycling in order to increase the solution concentration and reduce the post-treatment cost of the product .

Example 1. The concentrations of _SO2 , NO and ^Hg0 in the flue gas are 2000ppm, 500ppm and _100ug / ^m3 respectively, and the solid catalyst is _Fe2O3 particles (mass concentration is 1.0g/L, particle size is 100 mesh) , the flue gas temperature is 25°C, the wavelength of ultraviolet light is 254nm, the UV radiation intensity is 100W/m ³ , the molar concentration of hydrogen peroxide is 1.0mol/L, the liquid-gas ratio is 20L/m ³ , the effective residence time is 10s, and the distance between ultraviolet lamps When b and central angle a are 10cm and 25 degrees respectively, the integrated removal efficiencies of SO ₂ , NO and Hg ⁰ in flue gas can reach 92.1%, 80.9% and 98.8%, respectively.

Example 2. The concentrations of SO ₂ , NO and Hg ⁰ in the flue gas are 2000ppm, 500ppm and 100ug/m ³ respectively, and the solid catalyst is Fe ₂ O ₃ particles (mass concentration is 1.0g/L, particle size is 100 mesh) , the flue gas temperature is 25°C, the wavelength of ultraviolet light is 254nm, the UV radiation intensity is 150W/m ³ , the molar concentration of hydrogen peroxide is 1.0mol/L, the liquid-gas ratio is 20L/m ³ , the effective residence time is 10s, and the distance between ultraviolet lamps When b and central angle a are 10cm and 25 degrees respectively, the integrated removal efficiency of SO ₂ , NO and Hg ⁰ in the flue gas can reach 100%, 92.2% and 100%, respectively.

Example 3. The concentrations of SO ₂ , NO and Hg ⁰ in the flue gas are 2000ppm, 500ppm and 100ug/m ³ respectively, and the solid catalyst is Fe ₂ O ₃ particles (mass concentration is 1.0g/L, particle size is 100 mesh) , the flue gas temperature is 25°C, the wavelength of ultraviolet light is 254nm, the UV radiation intensity is 100W/m ³ , the molar concentration of hydrogen peroxide is 1.0mol/L, the liquid-gas ratio is 20L/m ³ , the effective residence time is 10s, and the distance between ultraviolet lamps When b and central angle a are 10cm and 25 degrees respectively, the integrated removal efficiencies of SO ₂ , NO and Hg ⁰ in flue gas can reach 89.2%, 83.2% and 100%, respectively.

Example 4. The concentrations of SO ₂ , NO and Hg ⁰ in the flue gas are 2000ppm, 500ppm and 100ug/m ³ respectively, and the solid catalyst is Fe ₂ O ₃ particles (mass concentration is 1.0g/L, particle size is 100 mesh) , the flue gas temperature is 25°C, the wavelength of ultraviolet light is 254nm, the UV radiation intensity is 50W/m ³ , the molar concentration of hydrogen peroxide is 1.0mol/L, the liquid-gas ratio is 15L/m ³ , the effective residence time is 10s, and the distance between ultraviolet lamps When b and central angle a are 10cm and 25 degrees respectively, the integrated removal efficiencies of SO ₂ , NO and Hg ⁰ in flue gas can reach 85.8%, 70.8% and 93.7%, respectively.

In summary, Example 2 has the best integrated desulfurization, denitrification and mercury removal effects, and can be used as a reference for the best example.

Claims (1)

1. integrated fume cleaning system based on heterogeneous Photo-Fenton, it is characterized in that: the burning and the exhaust system that be provided with burner, heat exchanger, bubble tower, add the liquid tower, two-stage knockout tower, regenerator, air-introduced machine and chimney consist of, burner combustion produces comprises SO ₂, NO _xAnd Hg ⁰Flue gas through after the heat exchanger cooling, the nozzle that arranges from the bubble tower bottom passes into bubble tower, the heterogeneous Fenton reagent that contains hydrogen peroxide and solid catalyst adds to add behind the liquid tower by the first circulating pump and also passes into bubble tower from the top of bubble tower, be provided with ultraviolet lamp tube in the bubble tower, flue gas and heterogeneous Fenton reagent produce the Gas-Liquid Absorption reaction in bubble tower, ultraviolet excitation decomposes heterogeneous Fenton reagent and discharges the hydroxyl radical free radical (OH) with strong oxidizing property, with the SO in the flue gas ₂, NO _xAnd Hg ⁰Be oxidized to H ₂SO ₄, HNO ₃And Hg ²⁺And be fixed in the solution, it is recycling that general's 20-40% mixed solution wherein adds the liquid tower by the second circulating pump suction, remaining mixed solution is then by sending into regenerator by the 4th circulating pump after the 3rd circulating pump suction one-level knockout tower precipitate and separate, again passed into by the 5th circulating pump behind the solid catalyst regeneration in the mixed solution and adds the liquid tower and recycle; Through the Hg that contains after the one-level separation ²⁺Solution is by the 6th circulating pump suction the second-order separation tower, by add the sulfidion S of equimolar ratio to the second-order separation tower ^2-Reaction generates the HgS of indissoluble, and through realizing the recycling of mercuric sulphide after the precipitate and separate, remaining high-concentration sulfuric acid and salpeter solution are recycled as the raw material of industry, and the flue gas after the washing passes through air-introduced machine suction smoke stack emission by the bubble tower top;

Said ultraviolet lamp tube is vertical with the bubble tower bottom surface, and unit volume ultraviolet radiation power is 5W/m in the bubble tower ³-200W/m ³, the W/m of unit ³Referred to bubble tower before uviol lamp is not installed, the needed ultraviolet radiation power of unit volume when bubble tower is void tower, ultraviolet wavelength is 120nm-360nm;

When many ultraviolet lamp tubes were set, many ultraviolet lamp tubes were the concentric circles setting, and distance is identical between the neighboring concentric circle, many ultraviolet lamp tubes are distributed on the circumference of different-diameter, along same diameter line setting, the central angle between each adjacent two diameter line is identical, and circle centre position is provided with ultraviolet lamp tube; Nozzle is arranged on the concentric circumference with ultraviolet lamp tube concentric circles alternate intervals uniform, and places on the diameter line of two ultraviolet lamp tube central angle half-angles;

Said solid catalyst is Fe ₂O ₃, MnO ₂, CuO or TiO ₂In a kind of, solid catalyst in regenerator by high-temperature calcination means activating and regenerating, its calcining heat is in 300 ℃ of-600 ℃ of scopes, the mass concentration that solid catalyst adds is in the 0.5g/L-5.0g/L scope, the particle diameter of solid catalyst is between 80 orders-200 order, and the molar concentration that hydrogen peroxide adds is at 0.1mol/L-2.5mol/L;

15 ℃-75 ℃ of the flue-gas temperatures of said bubble tower entrance, liquid-gas ratio is 5L/m ³-50L/m ³, and smoke gas flow is 0.5s-20s through the time of staying of bubbling column reactor,

The sulfidion S that adds in the said the second-order separation tower ^2-Mole and Hg solution ²⁺Mole equate i.e. n (S ^2-): n (Hg ²⁺)=1:1.

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