CN102039192B - Load type catalyst for treating organic wastewater and preparation method thereof - Google Patents

Abstract

A supported catalyst for oxidative treatment of organic wastewater and its preparation method, characterized in that the active component of the catalyst is Fe ²⁺ , and the loading capacity is 1% to 3%; the carrier is an epoxy resin-based porous polymer, with an average The particle size is 2mm to 5mm; it mixes polyethylene glycol, epoxy resin, and diethylenetriamine according to the mass ratio to obtain a viscous liquid, transfers it to an empty column to seal, reacts in a constant temperature box to obtain a white solid, and cools Finally, the white solid block is washed with deionized water to remove polyethylene glycol, and the epoxy resin-based porous polymer block material is obtained. The block material is cut into a catalyst carrier with a particle size of 2 mm to 5 mm. After drying, add to the concentration 0.1mol/L, pH 1-5 ferrous sulfate solution shakes at a constant temperature, and the solid is filtered, washed and dried to obtain the product. The supported catalyst of the invention has high catalytic activity and is easy to separate, and can be used in CWPO process to treat toxic, harmful and biodegradable organic waste water. The preparation process is simple and the cost is low, which is beneficial to popularization and use of the catalyst.

Description

A supported catalyst for treating organic wastewater and its preparation method

technical field

The invention relates to a supported catalyst which can be used for catalytic wet peroxide oxidation treatment of organic waste water at normal pressure and a preparation method thereof. The catalyst can be used in catalytic wet oxidation process under normal pressure to treat poisonous and harmful substances when used in combination with hydrogen peroxide. 1. Refractory biodegradable organic wastewater belongs to the field of water treatment.

Background technique

With the continuous development of chemical, pharmaceutical and other industries, the pollution of toxic, harmful and refractory organic substances has become a major global environmental problem, and the traditional wastewater treatment methods are not ideal for the removal of such substances. Advanced oxidation technology is an effective technical means to deal with toxic, harmful, and biodegradable organic substances. Commonly used advanced oxidation technologies include photocatalytic oxidation, ozone oxidation, Fenton (Fenton) reagent oxidation, catalytic wet oxidation, etc.

Catalytic wet oxidation (CWO) has been extensively studied due to its ability to quickly and effectively treat toxic, harmful, and refractory organic pollutants. Catalytic wet peroxide oxidation (CWPO) overcomes the defects of harsh operating conditions of CWO technology, and can realize rapid mineralization of organic pollutants at low temperature (even normal temperature) and normal pressure, so It can greatly reduce equipment investment cost and energy consumption, and has broad application prospects. Homogeneous CWPO technology has a high treatment efficiency for refractory organic pollutants, but it also has some disadvantages, such as the narrow application range of pH, and the difficulty of separating the catalyst from the wastewater, which may easily cause the loss of the catalyst and secondary pollution. Therefore, the development of cheap, highly active, highly stable, and easy-to-separate heterogeneous catalysts is the key to CWPO technology.

In recent years, some scholars have attempted to use inorganic materials as supports to prepare supported catalysts that can be used in heterogeneous CWPO processes. For example, Fajerwerg et al. published an article (Applied Catalysis B: Environmental 1996 (10) 229-235) loaded ferrous ions on silica, Al ₂ O ₃ and molecular sieve ZSM5, and performed heterogeneous CWPO degradation of phenol. The results showed that Fe ²⁺ /ZSM5 has the best catalytic effect, the phenol solution can be completely degraded in about 2 hours, the removal rate of TOC is 46%, the concentration of Fe ²⁺ and Fe ³⁺ in the solution after the reaction is lower than 5ppm, and the catalyst can be repeated use. Clay catalysts supported by Fe or Cu pillars are also common supported CWPO catalysts with excellent performance. For example, the research by Barrault et al. Clay is used as catalyst and H ₂ O ₂ is used as oxidant to degrade phenol solution. After 350 hours of continuous operation, the catalyst still maintains good catalytic activity, showing good catalytic effect and stability. However, the supported catalysts that can be used in the heterogeneous CWPO process also have some shortcomings, mainly as follows: (1) The preparation process of the supported catalyst is complicated, the secondary pollution is large, and the cost is high, which limits the industrial application; (2) ) Supported catalysts are generally powdery, and solid-liquid separation is difficult, which increases the complexity of the process; (3) Catalysts prepared with inorganic materials such as molecular sieves as carriers generally have a pore size less than 10 nanometers and low mass transfer efficiency. The organic matter degradation effect is poor.

Contents of the invention

The first technical problem to be solved by the present invention is to provide a new type of supported catalyst that can be used for catalytic wet peroxide oxidation treatment of organic wastewater at atmospheric pressure. The catalyst can be used for CWPO process to treat toxic, harmful and refractory organic wastewater , and high catalytic activity, easy to separate.

The first technical problem to be solved by the present invention is to provide a preparation method of a supported catalyst that can be used for atmospheric pressure catalytic wet peroxide oxidation treatment of organic wastewater with simple preparation process, less pollution and low cost.

The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a supported catalyst for treating organic wastewater, characterized in that: the active component of the catalyst is Fe ²⁺ , and the loading capacity is 1% to 3 %; the carrier of the catalyst is an epoxy resin-based porous polymer with an average particle diameter of 2 mm to 5 mm; the specific surface area of the catalyst is 158 m ² /g to 180 m ² /g, and has a mesopore or microporous structure.

As an improvement, the combined use of the supported catalyst and hydrogen peroxide can be used to catalyze a wet oxidation process under normal pressure to treat toxic, harmful and refractory biodegradable organic wastewater.

As an improvement, when the catalyst is operated, the reaction pressure is normal pressure 1 atm, the reaction temperature is 30°C-70°C, the reaction pH value is 2-5, and the oxidant used is hydrogen peroxide.

The present invention uses base metal Fe2 ⁺ as the active component of the catalyst, and the cost is low; the epoxy resin-based porous polymer has large specific surface area, adjustable pore diameter, high mechanical strength, acid and alkali resistance, stable combination with the catalyst active component, The advantages of easy separation from waste water; the preparation process of the catalyst is simple, fast, low in cost, small in secondary pollution, and has industrial application value.

The technical scheme adopted by the present invention to solve the above-mentioned second technical problem is: a preparation method of a supported catalyst for treating organic wastewater, which is characterized in that it includes the following steps in sequence:

In the first step, polyethylene glycol (PEG), epoxy resin, and diethylenetriamine are mixed according to a mass ratio of 12:6:1 to 12:6:3 to obtain a clear and transparent viscous liquid, and the above viscous liquid Transfer to an empty column to seal, and react in a constant temperature box at 60°C to 100°C for 8 hours to 96 hours to obtain a white solid. After cooling, the white solid block is repeatedly soaked and washed with deionized water to completely remove the porogen polyethylene glycol. Obtain an epoxy resin-based porous polymer block material, cut the block material into catalyst carriers with a particle size of 2 mm to 5 mm, dry it at 60 ° C to 90 ° C, and set it aside;

The second step: use deionized water to prepare a 0.05mol/L～0.5mol/L ferrous sulfate solution, adjust the pH value of the solution to 1～5, and then add a certain quality of catalyst carrier epoxy resin-based porous polymer. Oscillate with a constant temperature oscillator for 6 hours to 24 hours at room temperature, and control the mass ratio of the catalyst carrier to the ferrous sulfate solution to be 1:200 to 1:40;

Step 3: After the shaking is completed, the suspension is suction filtered, the solid is washed with deionized water until no Fe ²⁺ ions are leached, and finally the solid is baked at 50°C to 90°C for 12 hours to 48 hours to obtain the finished supported catalyst Fe ^{2 +} / Epoxy resin based porous polymer.

The molecular weight of the polyethylene glycol is 400-4000 (PEG400-PEG4000).

For the CWPO process in this project, the reaction pressure is 1 atm, the reaction temperature is 30°C-70°C, the reaction pH value is 2-5, and the oxidant used is hydrogen peroxide.

The epoxy resin is not particularly limited, and the usual E-51 or E-44 grade is preferred.

The present invention has the following advantages:

(1) The supported catalyst Fe of the present invention/epoxy resin-based porous polymer has a removal rate of up to 96.2 ^% after 1 hour for the CWPO degradation of the refractory organic pollutant azo dye Acid Orange 7, and the catalytic activity is better than or Equivalent to similar catalysts reported in the literature. The supported catalyst Fe ²⁺ /epoxy resin-based porous polymer of the present invention also has good catalytic activity when applied to CWPO treatment of nitrophenol, and the removal rate of nitrophenol can reach 90.8% after 1 hour.

(2) The supported catalyst Fe2 ⁺ /epoxy resin-based porous polymer of the present invention does not contain noble metal components, the preparation process is simple, fast, and the secondary pollution is small, thereby making the preparation cost of the catalyst greatly reduced, which is beneficial to the catalyst. industrial applications.

(3) The loaded catalyst Fe of the present invention/epoxy resin-based porous polymer is very stable due to the combination of the active component and ^the carrier, which greatly reduces the loss of the active component of the catalyst during use, measured by atomic absorption method , the dissolved amount of Fe in the catalyst is negligible, the catalyst has a long service life, can be used repeatedly, and does not cause secondary pollution.

(4) The supported catalyst Fe of the present invention/epoxy resin-based porous polymer epoxy resin has a large specific ^surface area, adjustable pore size, high mechanical strength, acid and alkali resistance, stable combination with catalyst active components, and easy integration with Wastewater separation.

(5) The preparation process of the catalyst is simple, rapid, low in cost, less in secondary pollution, and has industrial application value.

Detailed ways

Example 1:

After mixing polyethylene glycol (PEG2000), epoxy resin, and diethylenetriamine according to the mass ratio of 8:4:1 to obtain a clear and transparent viscous liquid, transfer the above viscous liquid into a glass empty column to seal, and React in a constant temperature box at 60°C for 24 hours to obtain a white solid. After cooling, the white solid block is repeatedly soaked and washed with deionized water to completely remove the porogen polyethylene glycol (PEG2000) to obtain an epoxy resin-based porous polymer block material. Cut the bulk material into catalyst carriers with a particle size of 2mm to 5mm, dry it at 60°C for later use; make 200 ml of 0.1mol/L ferrous sulfate solution with deionized water, adjust the pH value of the solution to 1, and then add 2 Gram catalyst carrier epoxy resin-based porous polymer was shaken at ^room temperature for 12 hours with a constant temperature oscillator; Bake at ℃ for 12 hours to obtain the finished supported catalyst Fe ²⁺ /epoxy resin-based porous polymer.

Weigh 0.4 g of this catalyst and put it into 400 mL of Acid Orange 7 solution with a concentration of 500 mg/L and 400 mL of nitrophenol solution with a concentration of 500 mg/L. The pH of the reaction solution is 3, the reaction temperature is 50 ° C, and the hydrogen peroxide concentration is 45 mmol/L. L. After the reaction time is 1 hour, the removal rate of acid orange 7 reaches 84.7%, and the removal rate of nitrophenol reaches 79.5%.

Example 2:

After mixing polyethylene glycol (PEG2000), epoxy resin, and diethylenetriamine according to the mass ratio of 8:4:1 to obtain a clear and transparent viscous liquid, transfer the above viscous liquid into a glass empty column to seal, and React in a constant temperature box at 60°C for 24 hours to obtain a white solid. After cooling, the white solid block is repeatedly soaked and washed with deionized water to completely remove the porogen polyethylene glycol (PEG2000) to obtain an epoxy resin-based porous polymer block material. Cut the bulk material into catalyst carriers with a particle size of 2 mm to 5 mm, dry it at 60 °C for later use; prepare 200 ml of 0.1 mol/L ferrous sulfate solution with deionized water, adjust the pH value of the solution to 3, and then add 1 Gram catalyst carrier epoxy resin-based porous polymer was shaken at room ^temperature for 12 hours with a constant temperature oscillator; Bake at ℃ for 12 hours to obtain the finished supported catalyst Fe ²⁺ /epoxy resin-based porous polymer.

Weigh 0.4 g of this catalyst and put it into 400 mL of Acid Orange 7 solution with a concentration of 500 mg/L and 400 mL of nitrophenol solution with a concentration of 500 mg/L. The pH of the reaction solution is 3, the reaction temperature is 50 ° C, and the hydrogen peroxide concentration is 45 mmol/L. L. After the reaction time is 1 hour, the removal rate of acid orange 7 reaches 92.6%, and the removal rate of nitrophenol reaches 84.3%.

Example 3:

After mixing polyethylene glycol (PEG2000), epoxy resin, and diethylenetriamine according to the mass ratio of 8:4:1 to obtain a clear and transparent viscous liquid, transfer the above viscous liquid into a glass empty column to seal, and React in a constant temperature box at 60°C for 24 hours to obtain a white solid. After cooling, the white solid block is repeatedly soaked and washed with deionized water to completely remove the porogen polyethylene glycol (PEG2000) to obtain an epoxy resin-based porous polymer block material. Cut the bulk material into catalyst carriers with a particle size of 2 mm to 5 mm, dry it at 60°C for later use; prepare 200 ml of 0.1 mol/L ferrous sulfate solution with deionized water, adjust the pH value of the solution to 5, and then add 1 Gram catalyst carrier epoxy resin ^- based porous polymer was shaken with a constant temperature oscillator for 12 hours at room temperature; Bake at ℃ for 12 hours to obtain the finished supported catalyst Fe ²⁺ /epoxy resin-based porous polymer.

Weigh 0.4 g of this catalyst and put it into 400 mL of Acid Orange 7 solution with a concentration of 500 mg/L and 400 mL of nitrophenol solution with a concentration of 500 mg/L. The pH of the reaction solution is 3, the reaction temperature is 50 ° C, and the hydrogen peroxide concentration is 45 mmol/L. L. After the reaction time is 1 hour, the removal rate of acid orange 7 reaches 96.2%, and the removal rate of nitrophenol reaches 90.8%.

Claims (2)

1. preparation method who handles the loaded catalyst of organic wastewater is characterized in that comprising successively following step:

(1) after being mixed according to mass ratio in 12: 6: 1～12: 6: 3, polyethylene glycol, epoxy resin, diethylenetriamine obtain the thick liquid of clear; Above-mentioned thick liquid changed in the empty tube column seal; Place insulating box, 60 ℃～100 ℃ of control certain reaction temperature are along with reaction is carried out reaction system by the transparent white that becomes; Through 8 hours～96 hours reaction time; White solid in obtaining managing, after the cooling with the white solid piece with deionized water repeatedly washing by soaking thoroughly remove the pore-foaming agent polyethylene glycol, obtain epoxy resin-matrix porous polymer bulk material; Bulk material is cut into the catalyst carrier that particle diameter is 2mm～5mm, and 60 ℃～90 ℃ dry backs are subsequent use;

(2) be made into the copperas solution of 0.05mol/L～0.5mol/L with deionized water; Regulator solution pH value 1～5; Add catalyst carrier epoxy resin-matrix porous polymer then; At room temperature with constant temperature oscillator vibration 6 hours～24 hours, control catalyst carrier and copperas solution mass ratio were 1: 200～1: 40;

(3) after vibration was accomplished, suspension suction filtration, solid spent deionised water to there not being Fe ²⁺Till ion leached, last solid dried by the fire down at 50 ℃～90 ℃ and obtained the finished product loading type catalyst Fe in 12 hours～48 hours ²⁺/ epoxy resin-matrix porous polymer.

2. preparation method according to claim 1, the molecular weight that it is characterized in that described polyethylene glycol is 400～4000.