CN105289629A

CN105289629A - Method for carrying out catalytic ozone degradation on new pollutant in water by lanthanum-based perovskite oxide

Info

Publication number: CN105289629A
Application number: CN201510658187.9A
Authority: CN
Inventors: 齐飞; 张钰婷
Original assignee: Beijing Forestry University
Current assignee: Beijing Forestry University
Priority date: 2015-10-14
Filing date: 2015-10-14
Publication date: 2016-02-03
Anticipated expiration: 2035-10-14
Also published as: CN105289629B

Abstract

The invention provides a preparation method for preparing a lanthanum-based perovskite oxide with a high specific surface area by utilizing a soft diaphragm plate and application of the lanthanum-based perovskite oxide in a catalytic ozonation technology, and belongs to the field of a water treatment technology and an environment functional material. A lanthanum-based perovskite oxide catalyst can be powder or particles in character and uses a surfactant CTAB and metal nitrate as main materials; the lanthanum-based perovskite oxide is prepared by adopting a precipitation method; capability of degrading an ultraviolet stabilizer PBSA in an advanced oxidation technology is improved. Aiming at the problem of poor effect on removing a new pollutant, i.e. the ultraviolet stabilizer PBSA, of the existing conventional sewage treatment, the invention discloses the preparation method which uses the perovskite oxide prepared by a soft diaphragm plate method as the catalyst, implements application in the advanced oxidation technology, overcomes the defects of conventional ozonation, and not only realizes the characteristics of simple process, low cost, low pollution to the environment and the like in the catalyst preparation, but also improves capability of generating active free radicals in ozone dissociation so as to implement effective removal on organic pollutants.

Description

A kind of emerging pollutant method in lanthanum based perovskite type oxide catalyst ozone degradation water

Technical field

The present invention relates to a kind of emerging pollutant method in preparation method of lanthanum based perovskite type oxide and catalysis ozone degradation water thereof.

Background technology

PBSA (2-phenylbenzimidazole-5-sulfonicacid is called for short PBSA), as a kind of active suncream composition, is one of the most basic medicine and personal care articles (PPCPs).As the water-soluble suncream composition of one, PBSA is a kind of novel micro organic pollution, has potential threat to the impact of water environment.Relevant research shows, this pollutant can be accumulated in adipose tissue by the aquatiles such as fish, and is probably transferred to the next generation.In addition, another harm of suncream shows in neonate's human milk samples and is found containing ultraviolet absorber.The sewage treatment plant that PBSA is being target and design-build with organics removal and some nutriments is difficult to remove, even without removal effect usually.This compounds may have certain environmental persistence and long-distance migration ability.Consider the impact of these pollutants on water quality, water quality safety must be ensured further by further treatment technique.

Heterogeneous catalytic ozonation technology is a kind of economic, efficient wastewater treatment technology of advanced oxidation, is that strengthening ozone oxidation removes one of new technology of high stability organic pollution in water.Be characterized in the hydroxyl radical free radical (OH) producing strong oxidizing property, non-selectivity, make the thorough mineralising of organic pollution be converted into carbon dioxide and water.The process appearing as emerging pollutant in a lot of water of this high-level oxidation technology provides new method.Heterogeneous catalytic ozonation technology utilizes catalyst as metal oxide, metal or metal oxide supported at carrier, active carbon and hollow microporous material etc., to promote that ozone decomposed produces more OH and carrys out degradable organic pollutant, and heterogeneous catalytic ozonation technology overcomes some problems of traditional ozonation technology, as yield of ozone is not high and utilization rate is lower, the oxidation activity of ozone has certain selective, thus adds the disposal cost etc. of ozone oxidation.Therefore, develop one not only economical and practical but also catalytic ozonation technology safely and effectively, prepare a kind of cheap and catalyst of better catalytic activity become solve existing issue in the urgent need to.

Composite oxides have excellent oxidation/reduction characteristic, high mechanical properties, good heat endurance, thus in modern chemical industry, are widely used as catalyst.Wherein, perovskite composite oxide is especially noticeable, and its general formula is expressed as ABO ₃.Its catalytic activity depends primarily on B bit element, at B position doping other alkaline-earth metal a small amount of or transition metal, can greatly change its catalytic performance.The effect of A position ion main stabilization structure.Just because perofskite type oxide has design flexibly, this type of material is quite favored in the field such as physics, chemistry.But the application prospect of these materials is limited due to its low specific surface area.Therefore, soft template method can be adopted to prepare mesoporous perovskite-type oxide catalysts, to the specific area adding raising catalyst by soft template, thus raising catalytic activity, and first form compared with hard template method the method that template adds perovskite again and compare, soft template method has the simple advantage of preparation process step.Therefore, be a kind of catalyst having bright prospects.

Summary of the invention

The present invention is directed to the polluted-water containing UV stabilizer PBSA, for solving the problem of existing conventional sewage poor processing effect, proposing of novelty prepares the application of perovskite-type oxide catalysts in heterogeneous catalytic ozonation technology with soft template method, and the Synthesis and applications condition of the perovskite-type oxide catalysts prepared for soft template method is described.The invention is intended to the specific area being improved perovskite-type oxide catalysts by the introducing of soft template, and adopt the precipitation method to prepare, utilize the self assembly ability of metal mesoporous to be formed, to improve the avtive spot of catalyst, thus improve the catalytic capability of catalyst, realize organic fast degradation.

The invention provides a kind of preparation and catalytic degradation UV stabilizer effect research thereof of lanthanum based perovskite type oxide, it is characterized in that (one) utilizes the ability of soft template and self assembly thereof, form loose structure; Novel perovskite-type oxide catalysts is prepared by means of the simple and easy precipitation method; Improve specific area and the pore volume of traditional perofskite type oxide, and then strengthening ozone is to the degradation capability of hardly degraded organic substance.; It is characterized in that (two) can complete preparation by following process: (1) takes 0 ~ 2g softex kw (CTAB), be at room temperature dissolved in 10 ~ 50ml deionized water; (2) in above-mentioned solution, add 2 ~ 8mmol lanthanum nitrate and 2 ~ 8mmol cobalt nitrate and stir, by solution warms to 60 ~ 80 DEG C, and stirring 30 ~ 60 minutes further; (3) reduce to after room temperature until solution temperature, dropwise adding 4.0mol/LNaOH to pH is 12 ~ 13, and solution gradually becomes suspension; (4) suspension is stirred 6 ~ 8 hours at 60 ~ 80 DEG C, then at room temperature stir 10 ~ 14 hours; (5) dry, the amorphous precursor of sample step (4) obtained puts into baking oven, at 90 ~ 110 DEG C, carry out drying crystalline; (6) calcine, the dried powder obtained through step (5) is calcined 3.8 ~ 4.2 hours at 700 ~ 800 DEG C; (7) cool, Temperature fall is to room temperature.

The invention provides a kind of preparation and catalytic degradation UV stabilizer effect research thereof of lanthanum based perovskite type oxide, it is characterized in that (three) this technique is realized by following step: O needed for (1) technique ₃concentration is 0.5 ~ 2.0mg/L; (2) needed for technique, lanthanum based perovskite type oxide catalyst throwing amount is 0.5 ~ 2.0g/L; (3) in staying water, pollutant levels are 2.0 ~ 10.0mg/L; (4) time of contact is 10 ~ 60min; (5) reaction system pH scope is 3.0 ~ 9.00.

Accompanying drawing content

That accompanying drawing is that detailed description of the invention one obtains take CTAB as LaCoO prepared by template ₃for catalyst removal usefulness figure to UV stabilizer PBSA in O3 catalytic oxidation system, wherein ■ represents the removal usefulness of independent ozone oxidation PBSA, ▲ represent CTAB/LaCoO ₃to the adsorption capacity of PBSA, ● represent CTAB/LaCoO ₃the usefulness of PBSA is removed in O3 catalytic oxidation.As can be seen from the figure, CTAB/LaCoO ₃the removal effect of the more independent ozonation technology of catalytic oxidation scrubbing technology to PBSA significantly improves, and CTAB/LaCoO ₃there is certain adsorption capacity to pollutant PBSA, can realize equally removing the strengthening of emerging pollutant PBSA in water body.

Detailed description of the invention

By the preparation method of this lanthanum based perovskite type oxide and be described in the application of the effect research of catalytic degradation water medium ultraviolet stabilizing agent, technical solution of the present invention is not limited to following exemplified detailed description of the invention, also comprises any combination between each detailed description of the invention.

Detailed description of the invention one: the preparation method of present embodiment lanthanum based perovskite type oxide catalyst is: (1) takes 0 ~ 2g softex kw (CTAB), is at room temperature dissolved in 10 ~ 50ml deionized water; (2) in above-mentioned solution, add 2 ~ 8mmol lanthanum nitrate and 2 ~ 8mmol cobalt nitrate and stir, by solution warms to 60 ~ 80 DEG C, and stirring 30 ~ 60 minutes further; (3) reduce to after room temperature until solution temperature, dropwise adding 4.0mol/LNaOH to pH is 12 ~ 13, and solution gradually becomes suspension; (4) suspension is stirred 6 ~ 8 hours at 60 ~ 80 DEG C, then at room temperature stir 10 ~ 14 hours; (5) dry, the amorphous precursor of sample step (4) obtained puts into baking oven, at 90 ~ 110 DEG C, carry out drying crystalline; (6) calcine, the dried powder obtained through step (5) is calcined 3.8 ~ 4.2 hours at 700 ~ 800 DEG C; (7) cool, Temperature fall is to room temperature.

In O3 catalytic oxidation system, scrubbing technology realizes according to following steps: O needed for (1) technique ₃concentration is 0.5 ~ 2.0mg/L; (2) needed for technique, lanthanum based perovskite type oxide catalyst throwing amount is 0.5 ~ 2.0g/L; (3) in staying water, pollutant levels are 2.0 ~ 10.0mg/L; (4) time of contact is 10 ~ 60min; (5) reaction system pH scope is 3.0 ~ 9.00.

The clearance of lanthanum based perovskite type oxide catalyst to UV stabilizer PBSA be prepared from present embodiment reaches more than 80%, the adsorption and oxidation to PBSA can be strengthened, achieve and the strengthening of UV stabilizer PBSA is removed, and catalyst preparation process is simple, cheap, be a kind of catalyst with extensive prospect.

In the effect research of the lanthanum based perovskite type oxide catalyst degradation water medium ultraviolet stabilizing agent that present embodiment obtains, can realize removing the strengthening of the emerging pollutant UV stabilizer PBSA of the difficult for biological degradation existed in water.Can find from accompanying drawing, adopt CTAB/LaCoO ₃can reach more than 80% as catalyst to the clearance of PBSA, more independent ozone oxidation improves 35 percentage points, and CTAB/LaCoO ₃catalyst has certain adsorption capacity, can improve equally and remove the strengthening of PBSA.

Claims

1. the present invention relates to a kind of emerging pollutant method in lanthanum based perovskite type oxide catalyst ozone degradation water, mainly comprise emerging pollutant method in the preparation method of novel lanthanum based perovskite type oxide and lanthanum based perovskite type oxide catalyst ozone degradation water, it is characterized in that: the ability utilizing soft template and self assembly thereof, form loose structure; Novel perovskite-type oxide catalysts is prepared by means of the simple and easy precipitation method; Improve specific area and the pore volume of traditional perofskite type oxide, and then strengthening ozone is to the degradation capability of hardly degraded organic substance.

2. novel lanthanum based perovskite type oxide catalyst according to claim 1, is characterized in that completing preparation by following process:

(1) take 0 ~ 2g softex kw (CTAB), be at room temperature dissolved in 10 ~ 50ml deionized water.

(2) in above-mentioned solution, add 2 ~ 8mmol lanthanum nitrate and 2 ~ 8mmol cobalt nitrate and stir, by solution warms to 60 ~ 80 DEG C, and stirring 30 ~ 60 minutes further.

(3) reduce to after room temperature until solution temperature, dropwise adding 4.0mol/LNaOH to pH is 12 ~ 13, and solution gradually becomes suspension.

(4) suspension is stirred 6 ~ 8 hours at 60 ~ 80 DEG C, then at room temperature stir 10 ~ 14 hours.

(5) dry, the amorphous precursor of sample step (4) obtained puts into baking oven, at 90 ~ 110 DEG C, carry out drying crystalline.

(6) calcine, the dried powder obtained through step (5) is calcined 3.8 ~ 4.2 hours at 700 ~ 800 DEG C.

(7) cool, Temperature fall is to room temperature.

3. the preparation of lanthanum based perovskite type oxide according to claim 1 and the effect research of catalytic degradation UV stabilizer thereof, is realized by following step:

(1) O needed for technique ₃concentration is 0.5 ~ 2.0mg/L;

(2) needed for technique, lanthanum based perovskite type oxide catalyst throwing amount is 0.5 ~ 2.0g/L;

(3) in staying water, pollutant levels are 2.0 ~ 10.0mg/L;

(4) time of contact is 10 ~ 60min;

(5) reaction system pH scope is 3.0 ~ 9.00.