Background technology
Along with developing rapidly of textile industry, the kind and the quantity of dyestuff increase day by day, and DYE PRODUCTION and dyeing waste water have become one of major polluting sources of water surrounding.According to statistics, in the DYE PRODUCTION process, 1 ton of dyestuff of every production will lose 2% product with waste water.And loss amount is bigger in dyeing process, is about 10% of used dyestuff.Waste water from dyestuff has characteristics such as colourity height, inorganic salt content height, composition complexity, biodegradability are poor, decolouring difficulty, and contains the multiple organism that has bio-toxicity or cause " three cause " (carcinogenic, teratogenesis, mutagenesis) performance.Even dye component concentration remaining in the waste water is very low, enter water body and also can cause the transmittance of water body to reduce, and the destruction that causes water ecosystem the most at last.Therefore, effectively dye wastewater treatment using has important theory and realistic meaning.
At present, the treatment process to waste water from dyestuff mainly comprises physics method, biochemical process, chemical method etc.Gac is a kind of physics method commonly used, but owing to be difficult for regeneration, treatment effect is undesirable, and its application is restricted; 20th century of membrane separation technique have begun industrial applications, being applied to the dye wastewater treatment aspect mainly is ultrafiltration and reverse osmosis, but because the existence of problems such as concentration polarization and film pollution, cause permeation flux in service to descend with the prolongation of working time, the price of film is more expensive simultaneously, the replacing frequency is very fast, so processing cost is higher, thereby seriously hinders the more massive industrial application of membrane separation technique.Biological process is low because of its running cost, treatment effect is good is used widely, but not ideal to the clearance of colourity.The processing cost of chemical oxidation and electrochemical oxidation is relative higher, and particularly advanced oxidation processes is in the laboratory study stage at present mostly, does not obtain practical application as yet.Though the Zero-valent Iron reduction method is a kind of important method of dye wastewater treatment using always, the reduction rate of common Zero-valent Iron is slow, efficient is lower.And the photochemical method that grew up in the last few years provides good solution route for the processing that solves poisonous and hazardous difficult degradation persistent organism in the environment.
The patent No. is that 200610024195.9 Chinese invention patent discloses " method of malachite green in a kind of degrading waste water ", this technology uses that content is the malachite green of 10mg/L in the 185nm ultraviolet degradation waste water, the flow velocity of waste water by 40-160L/h circulated in photoreactor, and degradation rate reaches more than 99% in the 40min.But this technology only is only applicable to degrading malachite green.
Application number is that 03137562.6 Chinese invention patent ublic specification of application discloses " a kind of photocatalysis oxidation method that is used for dye wastewater treatment ", and this method is used particulate state TiO
2Photocatalyst and fluidized-bed reactor, and use lower powered ultraviolet lamp to shine as electric light source, blast air simultaneously, make catalyzer in reactor, be fluidized state, this method can reach 69-95% to dye decolored rate, total organic carbon removing rate 47-75%.This method needs equipment such as fluidized-bed, ultraviolet lamp.
Two kinds of main artificial light of light source that photochemical method is commonly used and sunlights.Artificial light typically uses the high pressure ultraviolet lamp as light source, on the one hand, has a large amount of luminous energy and is converted into heat energy, and energy scatters and disappears, and light utilization efficiency is low; On the other hand, this light source need dispose stable-pressure device and cooling system, will cause complicated operation like this, and expense increases.Sunlight is operated simpler then more economically.
Therefore, in order better to solve the waste water from dyestuff pollution problem, with regard to a kind of efficient, simple, economic and safe treatment process of needs.
Summary of the invention
The object of the invention provides a kind of method of photocatalytic oxidation degradation waste water containing dye.
For achieving the above object, the technical solution used in the present invention is: a kind of method of photocatalytic oxidation degradation waste water containing dye, under the natural lighting condition, under the agitation condition, make photocatalyst suspended dispersed in containing the waste water of dyestuff, utilize the dyestuff in the airborne Oxygen Catalytic Oxidation degrading waste water, recycle photocatalyst; Described photocatalyst is platinum (Pt) nano wire of diameter less than 3nm; Specifically may further comprise the steps:
(1) be photocatalyst with diameter less than platinum (Pt) nano wire of 3nm, in pending waste water containing dye, add photocatalyst, under the natural lighting condition, under the agitation condition, make photocatalyst suspended dispersed in containing the waste water of dyestuff, catalytic oxidation 2~480 minutes;
(2) stop to stir, platinum (Pt) nano wire sinks under water, and discharges the upper strata and handles waste water, reclaims photocatalyst, and water flushing 2-3 can reuse after clean.
In the technique scheme, every 1L waste water need add photocatalyst 10-100mg; The preparation method of described photocatalyst Pt nano wire is a prior art, can reference: Angew.Chem.Int.Ed.2007,46, document on the 6333-6335 " universal method of synthetic Fe-Pt nano wire and nanometer rod " (A GeneralStrategy for Synthesizing FePt Nanowires and Nanorods), be specially: prepare the Fe-Pt nano wire earlier, then the Fe-Pt nano wire is scattered in the methanol solution, add again hydrochloric acid HCl and acetic acid HAc stir respectively under 60-70 ℃ removed outer Fe in 1-3 hour after centrifugal making.
In the technique scheme, described catalytic oxidation carries out under the solar light irradiation in air ambient.If solar irradiation less than the place, can be used as light source with infrared lamp.
In the technique scheme, the dyestuff in the described waste water that contains dyestuff includes but not limited to: rhodamine b, the pink B of slightly acidic, DISPERSE NAVY BLUE EXSF 300﹠ BLUE 56 100 HGL, DISPERSE BLUE 2BLN, acid peach GS, indigo K-3R, acid bright red 10B, dyestuff D1, sun-proof emerald green blue GL, lucifer yellow 8GFF, water-soluble purple dye
In the optimized technical scheme, the concentration of dyestuff is 5-60mg/L in the waste water.
Because the technique scheme utilization, the present invention compared with prior art has following advantage:
1, to adopt natural light be light source in the present invention, utilizes the Pt nano wire to be photocatalyst, and the dyestuff in the catalyzing oxidizing degrading waste water owing to select for use sunlight as light source, therefore has save energy, and cost is low, advantage simple to operate; And Pt nano wire photocatalytic activity height, stable performance, regeneration is simple, can reuse, and can not cause secondary pollution, is fit to large-scale production and application;
2, adopt the Pt nano wire among the present invention, by the mode that stirs can be in waste water suspended dispersed, do not need to use equipment such as fluidized-bed, not high to equipment and processing requirement; If reunion to a certain degree can take place the use nano particle, influence catalytic effect in whipping process;
3, technical scheme of the present invention is applied widely, and is better to the photocatalytic degradation effect of the dye composition of multiple difficult degradation, no matter be azo also be non-azo, tart is alkalescence still, fine degradation effect is all arranged, and do not need special processing.
Embodiment
Below in conjunction with embodiment the present invention is further described:
Following examples dye wastewater is industrial common dyes and deionized water.
Used instrument mainly contains U-3900 UV, visible light luminosity meter, magnetic stirring apparatus etc.
In the finite concentration scope, the concentration of dyestuff and its absorbancy meet lambert-law of Beer:
The concentration and the relation between the liquid layer thickness of absorbancy, solution are as follows:
A=εbc
(A is an absorbancy, and ε is a molar absorptivity, and b is a liquid pool thickness, and c is a strength of solution).
Following examples utilize this principle to measure the concentration of dyestuff in the solution of degraded front and back with ultraviolet-visible pectrophotometer in certain concentration range.
Calculate the dyestuff clearance according to following formula:
y=((C
o-C
e)/C
o)×100%
Y represents clearance C in the formula
oAnd C
eRepresent the concentration of initial and final dyestuff respectively.
Embodiment one
Choosing rhodamine b in the present embodiment is research object, dye wastewater.
The rhodamine b solution 50mL of preparation 5mg/L, get Pt nano wire 0.5-0.8mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out centrifugation behind the 2min, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff reaches 94.6%, and solution becomes achromaticity and clarification liquid at last.
Embodiment two
Choosing rhodamine b in the present embodiment is research object, dye wastewater.
The rhodamine b solution 50mL of preparation 10mg/L, get Pt nano wire 2.5-3.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, respectively in the sampling of reaction different time sections, sample takes out the back centrifugation, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.Calculate the clearance (percent of decolourization) of dyestuff.Along with the reaction times increases, liquid color shoals gradually, becomes achromaticity and clarification liquid at last.
Experimental result is as follows:
Reaction times (minute) |
??0 |
??20 |
??40 |
??60 |
??80 |
Dye decolored clearance (%) |
??0 |
??86.1 |
??91.8 |
??96.7 |
??99.8 |
Reaction after finishing is left standstill beaker, and the Pt nano wire sinks to beaker bottom, pours out the upper strata stillness of night, and the Pt line is washed the centrifugal recycling in back with clear water.Continue to add in beaker the rhodamine b solution of 10mg/L, dye solution becomes colorless after several minutes, and the clearance of dyestuff (percent of decolourization) reaches more than 95%.After the such repeated use of Pt nano wire 4 times, dye solution still presents colourless at last, and the dyestuff clearance also reaches more than 90%.
Embodiment three
Choosing rhodamine b in the present embodiment is research object, dye wastewater.
The rhodamine b solution 50mL of preparation 50mg/L, get Pt nano wire 2.5-3.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 8h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 89.8%.
Embodiment four
Choosing the pink B of slightly acidic in the present embodiment is research object, dye wastewater.
The pink B solution of the slightly acidic 50mL of preparation 20mg/L, get Pt nano wire 2.5-3.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 1h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 82.1%.
Embodiment five
Choosing DISPERSE NAVY BLUE EXSF 300﹠ BLUE 56 100 HGL in the present embodiment is research object, dye wastewater.
The DISPERSE NAVY BLUE EXSF 300﹠ BLUE 56 100 HGL solution 50mL of preparation 25mg/L, get Pt nano wire 4.0-4.5mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 5h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 71.1%.
Embodiment six
Choosing DISPERSE BLUE 2BLN in the present embodiment is research object, dye wastewater.
The DISPERSE BLUE 2BLN solution 50mL of preparation 20mg/L, get Pt nano wire 3.5-4.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 2h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 61.0%.
Embodiment seven
Choosing acid peach GS in the present embodiment is research object, dye wastewater.
The acid peach GS solution 50mL of preparation 25mg/L, get Pt nano wire 3.5-4.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 3h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 80.1%.
Embodiment eight
Choosing indigo K-3R in the present embodiment is research object, dye wastewater.
The indigo K-3R solution 50mL of preparation 25mg/L, get Pt nano wire 3.5-4.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 1h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 41.8%.
Embodiment nine
Choosing acid gorgeous 10B in the present embodiment is research object, dye wastewater.
The acid bright red 10B solution 50mL of preparation 25mg/L, get Pt nano wire 2.5-3.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 8h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 94.2%.
Embodiment ten
Choosing dyestuff D1 in the present embodiment is research object, dye wastewater.
The dyestuff D1 solution 50mL of preparation 25mg/L, get Pt nano wire 2.0-2.5mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 1h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 71.3%.
Embodiment 11
Choosing the emerald green blue GL of the direct sun-proof of dyestuff in the present embodiment is research object, dye wastewater.
The emerald green blue GL solution 50mL of the direct sun-proof of preparation 25mg/L, get Pt nano wire 2.0-2.5mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 2h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 67.9%.
Embodiment 12
Choosing dyestuff dispersion lucifer yellow 8GFF in the present embodiment is research object, dye wastewater.
The dispersion lucifer yellow 8GFF solution 50mL of preparation 25mg/L, get Pt nano wire 2.0-2.5mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 2h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 68.8%.
Embodiment 13
A kind of water-soluble purple dye of choosing in the present embodiment is used as research object, dye wastewater.This structure of matter is as follows:
This dye solution 50mL of preparation 50mg/L, get Pt nano wire 2.5-3.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, 1.5h back sample takes out the back centrifugation, supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 93.3%.
Embodiment 14
Choosing material that a kind of water-soluble bluish voilet can be used as dyestuff (referring to J.Med.Chem., 2010,53 (1), pp 368-373) in the present embodiment is research object, dye wastewater, and this structure of matter is as follows:
This dye solution 50mL of preparation 60mg/L, get Pt nano wire 4.5-5mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 1h, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 90.9%.
Embodiment 15
Choosing a kind of water-soluble yellow nitroso compound in the present embodiment is research object, dye wastewater, and this material is intermediate of multiple dyestuff synthetic, this structure of matter is as follows:
This dye solution 50mL of preparation 10mg/L, get Pt nano wire 1.5-2.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 30min, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 82.8%.
Embodiment 16
Choosing a kind of water-soluble dark brown nitroso compound in the present embodiment is research object, dye wastewater, and this material is intermediate of multiple dyestuff synthetic, this structure of matter is as follows:
This dye solution 50mL of preparation 10mg/L, get Pt nano wire 0.5-1.0mg, be placed on the magnetic stirring apparatus and stir, in air, be exposed under the sunlight, sample takes out the back centrifugation behind the 30min, and supernatant liquor is measured the concentration of excess dye with ultraviolet-visible pectrophotometer.The clearance (percent of decolourization) that calculates dyestuff is 84.4%.