A kind of preparation method of the catalyst for ultraviolet catalytic wet oxidation
Technical field
The present invention relates to a kind of preparation method of catalyst for ultraviolet catalytic wet oxidation, more particularly to one kind are available
In the preparation method of the catalyst of ultraviolet catalytic wet oxidation coal chemical industrial waste water film concentrate.
Background technique
For the requirement for meeting coal chemical industry " zero-emission ", coal chemical industrial waste water advanced treatment unit frequently with UF membrane
Technology.Membrane separation technique can carry out Selective Separation, but film point to impurity in coal gasification waste water on molecule or ion concentration
Essential from technology is separation pollutant, can not be degraded to pollutant, therefore can still generate during processing
A certain amount of film concentrate.Film concentrate has the characteristics that organic concentration is high, coloration is big, biodegradability is poor.How effectively
Process film concentrate is the significant challenge faced in coal chemical industrial waste water advanced treating.
Ultraviolet-catalytic wet peroxide oxidation (UV-CWPO) is in catalytic wet hydrogen peroxide oxidation system
(CWPO) ultraviolet light (UV) is introduced in, assists to promote using the effect direct photolysis organic pollutant of ultraviolet light and by ultraviolet light
Into catalysed oxidn degradable organic pollutant, organic and part inorganic pollution difficult to degrade in waste water is completely decomposed into
CO2, the harmless composition such as water, while can realize the harmless treatment of toxic wastewater with deodorization, decoloration and sterilizing, compared to
Catalysis wet-type oxidation technology reduces the temperature and pressure of conventional catalyst wet oxidation due to the introducing of ultraviolet light (UV).Catalysis
Agent is the key that ultraviolet-catalytic wet peroxide oxidation, and the active component in catalyst can reduce reaction condition, mention
High reaction efficiency, how to find a kind of catalyst of efficient stable is the key that promote this technology.Perovskite type catalyst is one
Kind crystal structure is the metal composite oxide of cubic system, has good structure-controllable, thermal stability, high catalytic efficiency and oxygen
Change the advantages that reducing power is strong, is with a wide range of applications in catalytic field.Gao Wenwen etc. has studied LaCoO3Ca-Ti ore type
Catalyst heterogeneous Fenton handles semi-coke wastewater, and under optimum process condition, the COD removal rate of semi-coke wastewater reaches
72.7%.Zou Wen waits quietly having studied LaBO3(B=Cr, Mn, Fe, Co, Ni) perofskite type oxide Surfactant dodecane
Base benzene sulfonic acid sodium salt (SDS) photolytic efficiency, wherein LaCoO3There is preferable degradation effect to SDS solution, degradation rate reaches
85.19%.
Summary of the invention
It is provided a kind of for ultraviolet catalytic wet oxidation the purpose of the invention is to improve the deficiencies in the prior art
The preparation method of catalyst, the catalyst can sufficiently cooperate as a kind of novel photochemical catalyst with the ultraviolet light in system,
And due to its structure-controllable, the feature that thermal stability is good, high catalytic efficiency, redox ability are strong, can be suitable for
Wet oxidation system, provides new approaches in order to overcome the deficiencies of the prior art.
The technical solution of the present invention is as follows: a kind of preparation method of the catalyst for ultraviolet catalytic wet oxidation of, specific
Steps are as follows:
(1) La (NO is stoichiometrically accurately measured3)3With Co (NO3)2It is dissolved in distilled water and forms mixed solution;
(2) citric acid is added into mixed solution to stir to being completely dissolved to form colloidal sol;
(3) drying forms gel at a certain temperature;
(4) by gel abrasive sieving for standby;
(5) LaCoO is obtained after heating calcining3Perovskite type catalyst.
La (NO described in preferred steps (1)3)3With Co (NO3)2Stoichiometric ratio be 1:(1~2);In mixed solution
The mass concentration of solute is 10%~20%.
The citric acid and metal ion molar ratio added in preferred steps (2) is 3:(1~2), colloidal sol is thick shape.
The temperature of drying described in preferred steps (3) is 90 DEG C~110 DEG C;Gel form is bread-like.
Grinding sieves with 100 mesh sieve in preferred steps (3).
Calcination temperature described in preferred steps (5) is 700 DEG C~900 DEG C, and calcination time is 5~7h;Gained catalyst
For grey powder.
Beneficial effects of the present invention:
(1) catalyst of the invention is prepared using sol-gel method, and synthesis technology is simple;
(2) catalyst of the invention is high-efficient, thermal stability is strong, redox ability is strong;
(3) catalyst of the invention, can be with ultraviolet-catalytic wet hydrogen peroxide as a kind of novel photochemical catalyst
Ultraviolet light in oxidation technology sufficiently cooperates, the catalytic efficiency in raising system;
(4) reaction condition needed for catalyst of the invention can reduce conventional catalyst wet oxidation, in the shape of low-temperature atmosphere-pressure
The oxidation to coal gasification film concentrate is realized under state, reduces operating cost;
(5) catalyst of the invention can realize recycling, good economy performance.
Detailed description of the invention
Fig. 1 is LaCoO3The X-ray diffractogram of perovskite type catalyst.
Fig. 2 is LaCoO3The scanning electron microscope (SEM) photograph of perovskite type catalyst.
Fig. 3 is LaCoO3The nonexpondable catalytic effect of perovskite type catalyst compares histogram.
Specific embodiment
Embodiment 1:
The preparation of the catalyst of the present embodiment carries out as follows:
(1) stoichiometrically 1:1 accurately measures La (NO3)3·nH2O and Co (NO3)2·6H2O is dissolved in a certain amount of steaming
The mixed solution that Solute mass concentration is 10% is formed in distilled water;
(2) citric acid (citric acid and metal ion molar ratio be 3:1) is added into mixed solution to stir to being completely dissolved
Form colloidal sol;
(3) drying forms gel at 90 DEG C;
(4) gel abrasive is sieved with 100 mesh sieve spare;
(5) 5h is calcined at 700 DEG C obtain LaCoO3Perovskite type catalyst;The X-ray diffractogram of gained catalyst and
Scanning electron microscope (SEM) photograph difference is as depicted in figs. 1 and 2.
Using catalyst manufactured in the present embodiment, using certain coal gasification film concentrate as process object, using it is ultraviolet-urge
Change wet-type peroxide oxidizing to be handled.Experiment carries out in photochemistry autoclave, takes 250ml waste water in reaction kettle
In, reaction condition: H is set2O2Dosage 1.2ml/L, catalyst amounts 0.8g/L, 120 DEG C of reaction temperature, reaction pressure
0.5MPa, pH=3, reaction time 60min.It is analyzed after reaction in sample tap sampling, the oxidation effect of 1 waste water of embodiment
Fruit is as shown in table 1.
Table 1
Detection project |
COD |
TOC |
UV254 |
Raw water |
1510 |
658 |
1.562 |
Oxidation water outlet |
184 |
114 |
0.05 |
Removal rate |
87.8% |
82.7% |
96.8% |
Embodiment 2:
The preparation of the catalyst of the present embodiment carries out as follows:
(1) stoichiometrically 2:3 accurately measures La (NO3)3·nH2O and Co (NO3)2·6H2O is dissolved in a certain amount of steaming
The mixed solution that Solute mass concentration is 15% is formed in distilled water;
(2) citric acid (citric acid and metal ion molar ratio be 2:1) is added into mixed solution to stir to being completely dissolved
Form colloidal sol;
(3) drying forms gel at 100 DEG C;
(4) gel abrasive is sieved with 100 mesh sieve spare;
(5) 6h is calcined at 800 DEG C obtain LaCoO3Perovskite type catalyst.
Catalyst prepared by Application Example 2, using certain coal gasification film concentrate as process object, using ultraviolet-catalysis
Wet-type peroxide oxidizing is handled.Experiment carries out in photochemistry autoclave, takes 250ml waste water in reaction kettle,
Reaction condition: H is set2O2Dosage 1.2ml/L, catalyst amounts 0.8g/L, 120 DEG C of reaction temperature, reaction pressure
0.5MPa, pH=3, reaction time 60min.It is analyzed after reaction in sample tap sampling, the oxidation effect of 2 waste water of embodiment
Fruit is as shown in table 2.
Table 2
Detection project |
COD |
TOC |
UV254 |
Raw water |
1510 |
658 |
1.562 |
Oxidation water outlet |
146 |
101 |
0.044 |
Removal rate |
90.3% |
84.6% |
97.2% |
Embodiment 3:
The preparation of the catalyst of the present embodiment carries out as follows:
(1) stoichiometrically 1:2 accurately measures La (NO3)3·nH2O and Co (NO3)2·6H2O is dissolved in a certain amount of steaming
The mixed solution that Solute mass concentration is 20% is formed in distilled water;
(2) citric acid (citric acid and metal ion molar ratio be 3:2) is added into mixed solution to stir to being completely dissolved
Form colloidal sol;
(3) drying forms gel at 110 DEG C;
(4) gel abrasive is sieved with 100 mesh sieve spare;
(5) 7h is calcined at 900 DEG C obtain LaCoO3Perovskite type catalyst.
Catalyst prepared by Application Example 3, using certain coal gasification film concentrate as process object, using ultraviolet-catalysis
Wet-type peroxide oxidizing is handled.Experiment carries out in photochemistry autoclave, takes 250ml waste water in reaction kettle,
Reaction condition: H is set2O2Dosage 1.2ml/L, catalyst amounts 0.8g/L, 120 DEG C of reaction temperature, reaction pressure
0.5MPa, pH=3, reaction time 60min.It is analyzed after reaction in sample tap sampling, the oxidation effect of 3 waste water of embodiment
Fruit is as shown in table 3.
Table 3
Detection project |
COD |
TOC |
UV254 |
Raw water |
1510 |
658 |
1.562 |
Oxidation water outlet |
177 |
109 |
0.05 |
Removal rate |
88.3% |
83.4% |
96.8% |
Embodiment 4:
By catalyst prepared by the embodiment 2 after first use after centrifugation, deionized water washing and being dried,
It repeatedly uses under the same conditions.Using certain coal gasification film concentrate as process object, using ultraviolet-catalytic wet
Hydrogen peroxide oxidation is handled.Experiment carries out in photochemistry autoclave, takes 250ml waste water in reaction kettle, is arranged
Reaction condition: H2O2Dosage 1.2ml/L, catalyst amounts 0.8g/L, 120 DEG C of reaction temperature, reaction pressure 0.5MPa, pH
=3, reaction time 60min.It is analyzed after reaction in sample tap sampling, the oxidation effectiveness of 4 waste water of embodiment such as 4 institute of table
Show, it can be seen that the catalyst catalytic performance for reusing 5 times shows that catalyst stability is good, such as Fig. 3 there is no significant change
It is shown.
Table 4
Detection project |
COD |
TOC |
UV254 |
Raw water |
1510 |
658 |
1.562 |
For the first time using water outlet |
147 |
101 |
0.044 |
For the second time using water outlet |
149 |
103 |
0.045 |
Third time uses water outlet |
154 |
105 |
0.047 |
4th use water outlet |
162 |
109 |
0.049 |
5th use water outlet |
168 |
112 |
0.052 |