CN1884148A - Process for treating dyeing waste water with high COD value and high colour - Google Patents

Abstract

The invention discloses a disposing method of high-COD value high-colority printing and dyeing wastewater, which comprises the following steps: 1. utilizing waste H2SO4 with Cl2 to adjust 70 percent weakly-acidic printing and dyeing wastewater; making pH value at 3-5; entering wastewater into micro-electrolyser reacting system; 2. adopting NaClO to adjust outlet without Fe++; adding NaOH until pH value is about 6; adding anion polyacrylamide to polymerize Fe (OH) 3 to sediment; 3. entering upper supernatant layer to catalyze O3 oxidizing reacting system through activated carbon with nanometer grade TiO2; removing O3 in the outlet through NaHSO3; 4. entering water in the biochemical reaction system to reach drainage standard. The invention removes colority in the printing and dyeing wastewater from 40 percent to 100 percent, which eliminates COD (1000-4000mg/L) from 10 percent to 60-90 percent.

Description

Treatment process to dyeing waste water with high COD value and high colour

Technical field

The present invention relates to a kind of treatment process of dyeing waste water, particularly use nano-TiO ₂The O3 catalytic oxidation method is to the treatment process of dyeing waste water with high COD value and high colour.

Background technology

Remove high chroma and high COD value in the dyeing waste water, become two key issues of long-term puzzlement dyeing water treatment.Along with chemical industry, dyestuffs industries and human consumer raising to the printing and dyeing processing request, the employing of novel dyeing and printing auxiliary, dyestuff, chemical sizwe and finishing composition constantly appears, be difficult to the widespread use of biodegradable organism in dyeing, cause that organic component becomes increasingly complex changeable in the dyeing waste water, greatly changed the character of waste water, increased intractability, biodegradability reduces greatly.Therefore, the clearance that how to improve COD is one of technical barrier anxious to be solved in the dyeing water treatment.

Can solve with the wet method catalytic oxidation, but need high temperature more than 280 ℃, working cost and investment are all expensive.How to reduce investment cost, how to reduce working cost, comparatively difficult especially thing.

The treatment process of present domestic routine: adopt " flocculation reflocculation "; " biochemistry is biochemical again " causes the working cost height, and floor space is big, and investment is big, handles back water outlet COD and colourity and still can not reach gratifying result.Also useful ozone oxidation method or photochemical catalytic oxidation decolouring and degraded COD, but for the high chroma of dyestuffs (accounting for 10%) such as weak acid dye (accounting for 70%) reactive dyestuffs (accounting for 20%) and dispersion and the printing and dyeing dual disposal waste water of high COD value, the clearance of directly logical ozone method or photochemical catalytic oxidation colourity and COD is respectively 40% and 10-40%, if the wide-scale adoption power consumption is too high.What abroad adopt usually is: one-level is just heavy, again through secondary biochemical, again through the method for three grades of charcoal absorptions, but the renovation process of gac and equipment, regeneration times is all limited, and it can only be brought in constant renewal in, and working cost is also high, show from test-results, extremely low for the eliminating rate of absorption of above-mentioned comprehensive discharge dyeing waste water gac.Also useful nano level TiO ₂Photocatalysis treatment printing and dyeing water, but be catalysis O with gac ₃Oxidation, the dyeing waste water of the high COD value of solution high chroma, data information does not appear in the newspapers at present.The proposition of present technique will solve above-mentioned these technological difficulties just.

Summary of the invention

For solving the problem that exists in the above-mentioned technology, the purpose of this invention is to provide a kind of treatment process, to solve this type of decolorization of dyeing and organic removal problem to dyeing waste water with high COD value and high colour.

For achieving the above object, the technical scheme that present technique adopts provides a kind of treatment process to dyeing waste water with high COD value and high colour, and its method may further comprise the steps:

1. will be that 1000-4000mg/L, colourity are＞5000 times dye printing and dyeing wastewater to contain 70% weakly acidic COD value, with containing Cl ₂Useless H ₂SO ₄Regulate, making PH is 3～5, enters the micro cell reactive system then, hydraulic detention time 6-10 hour;

2. water outlet is regulated with NaClO, transfers to no Fe ⁺⁺Exist, add NaOH to PH ≈ 6, add anionic polyacrylamide then and make Fe (OH) ₃Poly-glue, precipitation;

3. supernatant liquid enters with being loaded with nano level TiO ₂Activated carbon catalysis O ₃Oxidation system, the middle level of reaction tank dress gac 300mm bed thickness in the system, O ₃Gas distribution system is positioned at its layer down, reacts after 3-6 hour water outlet NaHSO ₃Remove O ₃

4. enter Biochemistry Reaction System then, anaerobic hydrolysis and aerobic, double oxygen alternate repetition carry out, and hydraulic detention time 12-20 hour, can reach as the subscript discharge index:

Handle back water-quality guideline: COD≤150mg/L; Colourity≤80 times; SS＜50mg/L; PH6-9.

Effect of the present invention be this method with carrying nano TiO 2 activated carbon catalysis ozone oxidation, ozone can be reached from (during catalyst-free) 40% clearance of such dyeing waste water colourity (2500-5000 is doubly) is increased to (the TiO2 activated-carbon catalyst is arranged) 100%; COD (1000-4000mg/L) is increased to 60-90% from about 10%.Thereby, solved the processing difficult problem of the dyeing waste water of the high COD value of high chroma difficult degradation.

Embodiment

In conjunction with the embodiments the treatment process to dyeing waste water with high COD value and high colour of the present invention is illustrated.

Present method realizes according to the following steps:

1, adopting the micro cell method, will be that 1000-4000mg/L, colourity are＞5000 times dye printing and dyeing wastewater to contain 70% weakly acidic COD value, add NaClO and contain Cl ₂Sulfur waste acid (the industrial sulfuric acid of making to contain after the chlorine dehydration 78% concentration), transfer PH3～5, hydraulic detention time 6-10 hour.Wherein the part larger molecular organics is decomposed into small organic molecule, removes partial organic substances simultaneously.Add NaClO then with Fe ⁺⁺Be oxidized to Fe ⁺⁺⁺, add NaOH to PH6-7, with anionic polyacrylamide with colloid Fe (OH) ₃Poly-glue, precipitation; It is about 50% that this COD degrades, percent of decolourization about 30%.The upper strata clear water enters TiO ₂Activated carbon catalysis O ₃Oxidation system.

2, TiO ₂Activated carbon catalysis ozone oxidation reaction system:

Supernatant liquid enters with being loaded with nano level TiO ₂Activated carbon catalysis O ₃Oxidation system, the middle level of reaction tank dress gac 300mm bed thickness in the system, O ₃Gas distribution system is positioned at its layer down, reacts after 3-6 hour water outlet NaHSO ₃Remove O ₃Be dark 3.0 meters of reaction tank in the reactive system, 1 meter has grid, glass steel to arrange net at the bottom of the pond, and it is thick to adorn the about 300mm of gac on the net; Grid is divided into O ₃Gas distribution pipe; The 300mm place is for receiving water system at the bottom of the pond.Also there is one deck grid underwater, reaction tank surface, is placed with on this grid that the thick glass steel cloth bag of about 50mm is equipped with gac so that absorption remains O ₃The dyeing waste water water distributor is positioned on the packed gac, surperficial underwater.In the pond, waste water and O ₃Cross-flow up and down.This moment, colourity reached below 80 times, and it is about 30% that COD removes again, and remaining larger molecular organics is the oxidized small-molecule substance that is decomposed into further.

3, Biochemistry Reaction System:

The combination ball-type filler (￠ 150mm plastic hollow porous spherical shell is filled out about 150-200 gram macrobead gac and nylon net in the ball, its proportion approaches 1) of volume about 30% is housed in the biochemistry pool, grid and air aeration pipe are arranged under the filler.Biochemical reaction tank divides three sections again: first section is anaerobic hydrolysis: under the anaerobic bacteria flora effect, larger molecular organics is converted into small organic molecule, bites the breeding of phosphorus bacterium jumpbogroup simultaneously, and nitrogen compound transfers ammonia nitrogen to.

Second section: the aerobic nitrification reactive system: most of organism is owing to the decomposition of a large amount of microorganisms, process such as synthetic change into CO ₂And H ₂O bites the phosphorus bacterium and absorbs phosphorus in a large number, and ammonia nitrogen transforms nitrate nitrogen.Owing to handle the microorganism of printing and dyeing water, its special efficacy flora belongs to this microorganism that generally is present in the physical environment in fact, just with the method for routine carried out domestication, spread cultivation, biofilm.The method of described routine is: printing and dyeing mill's sewage of the abundant amount of fetching is always arranged mouthful contains the same trade effluent of bacterium mud, clear water and nutriment (sanitary sewage or chemical fertilizer, some trade effluent does not need to add nutriment) mix sprinkle biological filter, back by suitable proportion, water outlet enters second pond, and with second pond as circulating water pool, circular flow.After microbial film mark phenomenon obviously appears in filter bed, be reference with the second pond effluent quality, in circulation, progressively adjust the ratio of trade effluent and water outlet, normal up to water outlet.At this moment, domestication-biofilm finishes.Because of microbial metabolism fast (20 minutes the fastest generation), easily tamed, and domestication back species easily are retained and breed.

The 3rd section is the oxygen section of holding concurrently: under double oxygen animalcule effect, nitrate nitrogen transfers N to ₂And H ₂O, by getting rid of the excess sludge dephosphorization, further degradation of organic substances is CO simultaneously ₂+ H ₂O, thus sewage is purified.

Make anaerobic hydrolysis and aerobic, double oxygen alternate repetition carry out about 12 hours of hydraulic detention time.

The principal pollutant index of water quality before handling:

COD1000-4000mg/L; Colourity 2500-5000 doubly; SS～500mg/L; BOD ₅/ COD＜0.1; PH5-7;

Handle back water quality: COD≤150mg/L; Colourity≤80 times; SS≤80mg/L; BOD ₅≤ 30mg/L; PH6-9.

Embodiment: Tianjin printing and dyeing mill, present main products is chemical ﹠ blended fabrics such as chemical fibre colored zone, uses weak acid dye to account for 70%, and reactive dyestuffs account for 20%, and also having other dispersion to wait dyestuff is 10%; In waste water, contain adhesive agent on a large amount of chemical fibres and fine chemical fiber and tinting material, adjustment agent or the like, leaving water temperature(LWT) is up to more than 70 ℃, but anaerobic hydrolysis such as no water collecting basin reaction, originally directly advanced Biochemistry Reaction System, behind the hydraulic retention 48 hours, COD clearance only about 20% always can not be up to standard, influences the development of enterprise.Water inlet COD1000-4000mg/L before it is handled; Colourity 2500-6000 extension rate; PH5-7; SS～500mg/L.Day water displacement 200m ³/ day.

It is as follows to transform aftertreatment technology by method of the present invention:

1, waste water is with containing Cl ₂PH to 4 is regulated in sulfur waste acid, enters micro electrolytic reaction system, and aerated reaction 5-6 hour is filler with waste iron filing and charcoal (gac and selected slag) in the system.Filler: water=10～20: 100; Iron filings: charcoal=5～3: 1.

2, water outlet is regulated with NaClO, transfers PH6-7 to there not being Fe with NaOH ⁺⁺(with the blue method qualitative detection in Prussian) adds anionic polyacrylamide then, flocculation, sedimentation, and supernatant liquid enters next processing unit.

3, enter the ozone catalytic reactive system, hydraulic detention time 6 hours, system is made up of three cement pits, and each is equipped with TiO ₂Thick and the ozonation aerated system of the about 300mm of gac.Through reaction water outlet in 3-6 hour water white transparency, if COD be up to standard can the discharging, if not up to standardly enter following treatment system.

4, in above-mentioned water outlet, add earlier sodium bisulfite (0.5% solution) to the shallow lake little blue look of amount Faxian and show O ₃Oneself removes.

5, enter Biochemistry Reaction System (biological filter process), the wherein used bacterium mud that contains is always arranged a mouthful extraction from this factory's sewage.Hydraulic detention time 12-20 hour (relevant with temperature), water outlet gets final product qualified discharge.

Claims (1)

1, a kind of treatment process to dyeing waste water with high COD value and high colour, its method may further comprise the steps:

1. will be that 1000-4000mg/L, colourity are＞5000 times dye printing and dyeing wastewater to contain 70% weakly acidic COD value, with containing Cl ₂Useless H ₂SO ₄Regulate, making PH is 3～5, enters the micro cell reactive system then, hydraulic detention time 6-10 hour;

2. water outlet is regulated with NaClO, transfers to no Fe ⁺⁺Exist, add NaOH to PH ≈ 6, add anionic polyacrylamide then and make Fe (OH) ₃Poly-glue, precipitation;

3. supernatant liquid enters with being loaded with nano level TiO ₂Activated carbon catalysis O ₃Oxidation system, the middle level of reaction tank dress gac 300mm bed thickness in the system, O ₃Gas distribution system is positioned at its layer down, reacts after 3-6 hour water outlet NaHSO ₃Remove O ₃

4. enter Biochemistry Reaction System then, anaerobic hydrolysis and aerobic, double oxygen alternate repetition carry out, and hydraulic detention time 12-20 hour, can reach as the subscript discharge index:

Handle back water-quality guideline: COD≤150mg/L; Colourity≤80 times; SS＜50mg/L; PH6-9.