CN105800767B - The structure of a kind of nanometer of mangaic acid copper spinelle catalytic film reactor and its application process in water process - Google Patents

Abstract

The invention relates to a heterogeneous catalytic ozone oxidation decontamination water advanced treatment technology, aiming at the disadvantages of conventional powder catalysts, such as unfavorable separation in the water phase and easy deactivation, etc., a new nano-copper manganate spinel catalytic membrane reactor is proposed The construction method. It combines heterogeneous catalytic ozone oxidation with ceramic membrane filtration technology, uses the active component (CuMn ₂ O ₄ ) on the ceramic membrane catalytic layer to catalyze ozone to generate OH with high oxidation ability, organic matter can react directly with molecular ozone, Or react with OH produced by ozonolysis, and the interception effect of ceramic membrane can also assist in strengthening the removal of 2-hydroxy-4-methoxybenzophenone in water. In addition, ozone can react with humic acid and natural organic matter (NOMs) in water, effectively preventing the formation of membrane fouling. The nano-copper manganate spinel catalytic membrane has a simple preparation process and is easy to operate. The catalyst on the membrane surface is evenly distributed, which improves the mass transfer efficiency and has potential application prospects in the treatment of drinking water or sewage containing PPCPs.

Description

Construction of a Nano Copper Manganate Spinel Catalytic Membrane Reactor and Its Application in Water Treatment application method

technical field

The invention relates to the construction of a nano-copper manganate spinel catalytic membrane reactor and its application in catalytic ozone oxidation and pollution removal technology.

Background technique

In recent years, new pollutants with "three-caused" effects or endocrine disrupting effects——pharmaceuticals and personal care products (PPCPs) have been continuously detected and found in the surface water environment, with concentrations ranging from ng/L to μg/L. Most of the PPCPs are discharged into the sewage in the original or converted form and enter the sewage treatment plant with the sewage. The representative substances of the PPCPs detected include antimicrobial drugs, antipyretic, analgesic and anti-inflammatory drugs, estrogen and other drugs (such as blood lipids, drugs, etc.) Antiepileptic drugs, tranquilizers, contrast agents, etc.) and fragrances commonly used in cosmetics. Since conventional water treatment and sewage treatment processes are water treatment systems that mainly remove suspended and colloidal pollutants in water, their ability to remove organic pollutants, especially refractory organic pollutants, is very limited or even powerless. Therefore, low concentration and high stability PPCPs in water pose a great threat to surface water quality and ecological security. To this end, it is very important to carry out basic theory and application research on the enhanced removal technology of PPCPs pollutants, and provide scientific basis and technical support for developing economical and efficient water advanced treatment technology, ensuring water quality safety, and improving water environment quality. and practical significance.

The heterogeneous catalytic ozonation technology is one of the common water advanced treatment technologies. It does not introduce other energy and toxic and harmful chemicals into the process. The catalyst can be filled in the reactor at one time, which is simple to operate and convenient to use in the actual process. It has a great application prospect in water treatment process. The catalysts involved in the heterogeneous catalytic ozonation technology are mainly metal oxides (Al ₂ O ₃ and MnO ₂ , etc.), metals or metal oxides (Cu/TiO ₂ , Cu/Al ₂ O ₃ , etc.) ) and porous materials with large specific surface area. The activity of these catalysts is mainly manifested in the catalytic decomposition of ozone and the promotion of the generation of hydroxyl radicals. However, these common catalysts with high catalytic activity also have some limitations:

(1) Most of the catalysts are powdery, although they have a large specific surface area and reactivity, they are unfavorable for realizing their separation in water;

(2) The cost is high, and the catalyst has certain selectivity, so it is difficult to meet the actual demand;

(3) Due to the coexistence of various pollutants in natural water bodies, the adsorption of some substances and their oxidized intermediates leads to the decline or loss of catalytic activity.

Therefore, it is necessary to develop a new type of catalyst, on the basis of further improving the catalytic activity, realize the efficient separation of powder catalyst and water and eliminate the poisoning problem of the catalyst, and apply it to the heterogeneous ozone catalytic oxidation technology to solve the problem of low Concentration of refractory organic pollutants removal problem.

Membrane separation technology refers to the technology that achieves selective separation of mixtures of different particle molecules at the molecular level when they pass through a semi-permeable membrane. It has the functions of separation, concentration, purification and refining, and has the characteristics of high efficiency, energy saving, environmental protection, molecular level filtration and simple filtration process, easy to control, etc. It has been widely used in food, medicine, biology, environmental protection, chemical industry and electronics, etc. field. Among them, ceramic membranes have been widely used in water treatment processes due to their advantages of high separation efficiency, good chemical stability and low energy consumption. It is a kind of inorganic membrane, an asymmetric porous membrane mainly made of inorganic materials such as Al ₂ O ₃ , ZrO ₂ , TiO ₂ and SiO ₂ . Its filtration precision covers microfiltration and ultrafiltration. The pore size of microfiltration membrane is 0.05-1.4μm, and the precision of ultrafiltration membrane is 10-50kDa. The ceramic filter membrane in wastewater treatment is prepared by the sol-gel method, and the tube wall is densely covered with micropores. Under pressure, the raw material liquid flows in the membrane tube or outside the membrane, small molecular substances (or liquid) pass through the membrane, and macromolecular substances (or solids) are intercepted by the membrane, so as to achieve the purposes of separation, concentration, purification and environmental protection. However, membrane fouling occurs during membrane filtration. It refers to the adsorption and deposition of particles, colloidal particles or solute macromolecules in the water on the surface of the membrane or in the pores of the membrane due to the physical, chemical or mechanical interaction with the membrane, causing the membrane pore size to become smaller or blocked, causing the membrane to generate permeation flow. The phenomenon of irreversible changes in separation characteristics, the most common of which is membrane fouling caused by humic acids and natural organic matter (NOMs) in water. Membrane fouling has been regarded as an important problem in the engineering application of ceramic membranes, which will affect the stable operation of the membrane and determine the replacement frequency and service life of the membrane. Therefore, appropriate measures must be taken to reduce or eliminate the adverse effects of membrane fouling.

The nano-copper manganate spinel catalytic membrane reactor involved in the present invention can combine heterogeneous catalytic ozone oxidation with ceramic membrane filtration technology, and use the active component (CuMn ₂ O ₄ ) on the ceramic membrane catalytic layer to catalyze ozone generation Hydroxyl radicals with high oxidizing ability, organic matter can directly react with ozone molecules, or react with OH produced by ozonolysis, to achieve efficient removal of refractory organic pollutants; at the same time, the interception effect of ceramic membranes can also assist in the realization of enhanced ozone oxidation. degrade organic matter. More importantly, ozone can react with natural organic matter in water, effectively preventing the formation of membrane fouling. The construction of the catalytic membrane reactor overcomes the shortcomings of conventional powder catalysts that are not easy to separate from water, and provides a new method for catalyst cleaning and multiple recycling.

Contents of the invention

1. technical scheme of the present invention is as follows, the construction method of nano-copper manganese acid spinel (CuMn ₂ O ₄ ) catalytic membrane reactor can be realized by following several steps:

(1) Accurately weigh 40.1893g of citric acid monohydrate and dissolve it in 800mL of deionized water to completely dissolve the solute to obtain a clear solution;

(2) Add 10.2681g Cu(NO ₃ ) ₂ ·3H ₂ O and 10.2mL Mn(NO ₃ ) ₂ with a concentration of wt.50% to the above solution, and at the same time, keep stirring the mixed solution at 600rpm/min for 24h to make the solute Dissolve completely to obtain a clear solution;

(3) The above solution is heated and stirred at 150°C, and the heating is stopped after the sol is formed;

(4) Soak the ceramic membrane in the above-mentioned sol solution and let it stand for 60 minutes;

(5) Place the once-loaded ceramic film in a high-temperature muffle furnace for burning, the burning temperature is 750°C, the burning time is 240min, the heating rate of the muffle furnace is 2°C/min, and then naturally cool to room temperature;

(6) Steps (4) and (5) were repeated three times to complete the construction of the nano-copper manganate spinel catalytic membrane reactor.

2. The outstanding effects of the present invention are as follows:

The nano-copper manganese oxide spinel catalytic membrane reactor is designed to combine heterogeneous ozone oxidation with ceramic membrane filtration technology, using the active component (CuMn ₂ O ₄ ) on the ceramic membrane catalytic layer to catalyze ozone to produce hydroxyl with high oxidation ability Free radicals and organic matter can react directly with ozone molecules, or react with OH produced by ozonolysis, and the interception effect of ceramic membranes can also assist in the strengthening of ozone oxidation for refractory organic matter. In addition, ozone can react with natural organic matter (NOMs) in water bodies, effectively preventing membrane fouling from forming. The catalytic membrane reactor overcomes the shortcomings of conventional powder catalysts that are not easy to separate from water, and provides a new method for catalyst cleaning and multiple recycling.

Description of drawings

Accompanying drawing 1 shows the construction method of the nano-copper manganese oxide spinel catalytic membrane reactor, first prepares the mixed sol by sol-gel method, then soaks the ceramic membrane in the sol mixed solution, then calcines the ceramic at a high temperature under the condition of 750°C membrane, repeat the soaking and calcination process three times to obtain a highly catalytically active supported nano-copper manganese spinel catalytic membrane.

Accompanying drawing 2 is the nano-copper manganate spinel catalyst film of different loadings to the removal performance figure of BP-3 in water, and experimental condition is: the initial concentration of 2-hydroxyl-4-methoxybenzophenone [BP- 3] ₀ ＝2.0mg/L, the concentration of dissolved ozone in water [O ₃ ] ₀ ＝1.0mg/L, pH＝7.24±0.15. It can be seen from the figure that the degradation rate of BP-3 by the CuMn ₂ O ₄ catalyzed ceramic membrane is significantly higher than that of the unmodified ceramic membrane (51.6%). The degradation rate of dipping once (60min) was 71.2%, while the ceramic membrane dipped twice (120min) and dipped three times (180min) had no significant difference in the degradation effect of BP-3, and the removal rates were 76.5% and 76.6% respectively . With the increase of immersion times and time, the removal rate of BP-3 also increased, but when the adsorption of the ceramic membrane reached saturation, the catalyst loading reached the maximum and the removal effect was the best.

Detailed ways

The construction method of the catalyst membrane reactor loaded with nano-copper manganate spinel will be described below in conjunction with specific embodiments, so as to further understand the invention. The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

Embodiment 1: The construction method of nano-copper manganate spinel (CuMn ₂ O ₄ ) catalytic membrane reactor can be realized through the following steps:

(1) Accurately weigh 40.1893g of citric acid monohydrate and dissolve it in 800mL of deionized water to completely dissolve the solute to obtain a clear solution;

(2) Add 10.2681g Cu(NO ₃ ) ₂ ·3H ₂ O and 10.2 mL of wt.50% Mn(NO ₃ ) ₂ to the above solution, and at the same time, keep stirring the mixed solution at 600rpm/min for 24h to make the solute completely dissolved to obtain a clear solution;

(3) The above solution is heated and stirred at 150°C, and the heating is stopped after the sol is formed;

(4) Soak the ceramic membrane in the above-mentioned sol solution and let it stand for 60 minutes;

(5) Place the once-loaded ceramic film in a high-temperature muffle furnace for burning, the burning temperature is 750°C, the burning time is 240min, the heating rate of the muffle furnace is 2°C/min, and then naturally cool to room temperature;

(6) Steps (4) and (5) were repeated three times to complete the construction of the nano-copper manganate spinel catalytic membrane reactor.

The loaded nano-copper manganate spinel catalytic membrane reactor assembled in this embodiment has a better removal rate of PPCPs containing 2-hydroxyl-4-methoxybenzophenone than the existing conventional powdery heterogeneous catalysts. CuMn ₂ O ₄ on the membrane catalyzes ozone to generate hydroxyl radicals with high oxidizing ability, and at the same time, membrane interception can also remove a small part of PPCPs, which greatly reduces the cost of water treatment and improves the pollution removal ability of water treatment technology. In addition, CuMn ₂ O ₄ nanoparticles loaded on the surface of ceramic membrane can effectively realize the separation of catalyst and water.

Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that 10.2681gCu(NO ₃ ) ₂ ·3H ₂ O in step (2) can be replaced by 8.4851gCu(CH ₃ COO) ₂ ·H ₂ O, other steps And the parameters are the same as those in Embodiment 1.

Embodiment 3: The difference between this embodiment and Embodiment 1 is that the concentration of 10.2 mL in step (2) is wt.50% Mn(NO ₃ ) ₂ can be replaced by 22.7885 g Mn(CH ₃ COO) ₂ ·2H ₂ O , other steps and parameters are the same as those in the first embodiment.

Embodiment 4: The difference between this embodiment and Embodiment 1 is that heating and stirring at 150°C in step (3) can be replaced by heating in a water bath at 150°C.

Claims (3)

1. a kind of nanometer of mangaic acid copper spinelle (CuMn₂O₄) catalytic film reactor structure and its application process in water process, It is characterized in that：Using ceramic membrane as carrier, the nanometer mangaic acid copper spinelle with high activity is carried on catalysis film surface, is formed Catalytic film reactor；The CuMn of high catalytic activity₂O₄It is carried on ceramic membrane surface, realizes point of nanometer powder catalyst and water From, for catalyst cleaning and be recycled for multiple times and provide new method；Catalytic film reactor can be by heterogeneous catalysis ozone oxygen Change is combined with ceramic membrane filter technology, and the reinforcing to ozone oxidation is completed in the form of catalytic membrane；Catalytic Layer is utilized simultaneously Catalytic action completes the elimination and degradation of the fouling membrane factor, prevents the formation of fouling membrane；Wherein, CuMn₂O₄Catalytic film reactor It completes to build by following steps：

(1) precise 40.1893g monohydrate potassiums, are dissolved in the deionized water of 800mL, and solute is made to be completely dissolved, with Obtain clear solution；

(2) by 10.2681g Cu (NO₃)₂·3H₂Mn (the NO of a concentration of wt.50% of O and 10.2mL₃)₂It is added in above-mentioned solution, Mixed solution is persistently stirred for 24 hours with 600rpm/min simultaneously, so that solute is completely dissolved, to obtain clear solution；

(3) above-mentioned solution heating stirring under the conditions of 150 DEG C stops heating after colloidal sol is formed；

(4) ceramic membrane is immersed in above-mentioned sol solution, stands 60min；

(5) primary ceramic membrane will be loaded and be placed on calcination in high temperature Muffle furnace, calcination temperature is 750 DEG C, and calcination time is The heating rate of 240min, Muffle furnace are 2 DEG C/min, later cooled to room temperature；

(6) step (4), (5) 3 times, the i.e. structure of completion nanometer mangaic acid copper spinelle catalytic film reactor are repeated.

2. described in accordance with the claim 1 nanometer of mangaic acid copper spinelle (CuMn₂O₄) catalytic film reactor structure, feature exists It is used by α-Al in the membrane module₂O₃For inner standoff layer, ZrO₂For the tubular ceramic film of filter layer；Its The concrete specification is Length 25.0cm, port number 4~19, outer diameter 30mm, 0.12~0.20m of membrane area², fenestra size is 10.0~50.0nm.

3. a kind of using nanometer mangaic acid copper spinelle (CuMn described in claim 1₂O₄) catalytic film reactor is in water process Using being realized by following steps：

(1) ozone concentration needed for technique is 0.5~2.0mg/L；

(2) ozone gas flow velocity needed for technique is 200~400mL/min；

(3) a concentration of 0.002~0.018mmol/L of persistent organic pollutants is horizontal in staying water；

(4) ranging from 6.0~8.0 staying water pH；

(5) operating parameter of load nanometer mangaic acid copper spinelle catalytic film reactor is：Regurgitant volume 3.0m³/ h, pressure 0.11Mpa, 20~30 DEG C of operation temperature.