CN86107846A - The methyne urea precipitator method are removed the formaldehyde in the trade effluent - Google Patents
The methyne urea precipitator method are removed the formaldehyde in the trade effluent Download PDFInfo
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- CN86107846A CN86107846A CN 86107846 CN86107846A CN86107846A CN 86107846 A CN86107846 A CN 86107846A CN 86107846 CN86107846 CN 86107846 CN 86107846 A CN86107846 A CN 86107846A CN 86107846 A CN86107846 A CN 86107846A
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Abstract
The present invention is a method of removing formaldehyde with the sedimentary form of methyne urea from trade effluent; belong to the wastewater processing technology in the field of environment protection; the present invention makes catalyzer with acids; under normal temperature or waste water boiling temperature; utilize the formaldehyde in urea and the waste water to react; generate insoluble methyne urea white precipitate; separating reaction precipitated product then; to remove the formaldehyde in the trade effluent; for containing the waste water of formaldehyde 3%, the formaldehyde clearance is 97～99%, and the present invention has the aldehyde removal method selectivity strong; be not subjected to the interference of other coexistence components in the waste water, aldehydes removal rate advantages of higher.
Description
The invention belongs to field of environment protection, is a kind of wastewater processing technology.Its purpose is to remove formaldehyde with methyne urea solid form from trade effluent.The protection environment prevents to pollute.
One, at production fields such as paint, plastics, pharmacy, synthetic resins, petrochemical complex, textile chemical fibers, often runs into the discharging and the handling problem of formaldehyde waste liquid and waste water.Formaldehyde toxicity is bigger, is comparatively common environmental pollution component.
Aspect the formaldehyde waste water treatment technology, many patented technologies have been invented.For example:
1, Japanese Patent (clear 49-132006) ammonification in aldehyde-containing sewage changes into urotropin with formaldehyde, with reduction toxicity, but does not separate.4088818 of United States Patent (USP)s have taked to add operations such as ammonia react, evaporation, crystallization, drying, produce the urotropin byproduct from waste water.4338196 of another patents of the U.S. do not reclaim product after adding ammonia react, and adopt biochemical process to handle.In similar ammonification treatment process, also has the method for Japanese Patent (clear 49-94626), ammonification or ammonium salt aldehydes removal from mill solution; Japanese Patent (clear 50-038957) is removed formaldehyde with diacetyl acetone from waste water in the presence of ammonium salt.
2, Japanese Patent (open special permission, clear 54-3002) adopts through the cupric oxide of special activation treatment and makes catalyzer, makes formaldehyde carry out disproportionation reaction under alkaline condition, is transformed into formaldehyde and sodium formate.Another patent of Japan (clear 49-087613) also is the method that adds alkaline purification formaldehyde.These method alkali consumptions are big, still have secondary pollution.
3, Japanese Patent (clear 49-073849) heats under calcium salt catalysis, with the formaldehyde in the method removal waste water of oxygen oxidation.Japanese Patent (clear 56-111085) then is under the copper sulfate katalysis, removes formaldehyde with hydrogen peroxide oxidation.The Soviet Union then is reported under the mantoquita catalysis, by activated carbon catalytic oxidation bed, carries out oxidation with air.Strong oxidizers such as still useful in addition chlorinated lime, clorox, chlorine, ozone carry out the industrial example of oxide treatment.The oxidation style poor selectivity is subject to the interference of other background components in the water.
4, during the formaldehyde of the Soviet Union in reclaiming vinylon plant waste water, be in water, to add saltcake or calcium chloride, (example 5 gram CaCl
2/ 100ml), make the formaldehyde depolymerization, reclaim formaldehyde (see C, A, VOL64, № 12, P11763,1966) by distillation then.
5, du pont company once adopted the method for wet oxidation, handled to contain 5% formaldehyde and to contain methyl alcohol and the waste water of formic acid (seeing " chemical pollution and prevent " book).Oxidation is to carry out under 700 ℃ and condition of high voltage.The also useful wet oxidation process of Japan is handled the example of 1% aldehyde-containing sewage.Wet oxidation needs high-tension apparatus and higher technical qualification, is difficult for promoting.
6, the phenolic aldehyde polymerization is handled the waste water that contains phenol and contain aldehyde, abroad with domestic all existing numerous industrial example.As Japanese Patent (clear 57-75187), russian patent 791607,743952,829582 all belongs to this example.Domestic Tianjin resin processing plant (seeing " environment protection " № 5, P19,1979), Changchun chemical industry two factories (seeing " chemical industry environmental protection " № 4, P195,1983), Shanghai Plastic Factory, Xinhua Resin Factory, Shanghai etc. be industrial application already all.But adopt the main purpose of phenolic aldehyde polymerization, still remove phenol with excessive aldehyde, the effect of aldehydes removal is also unsatisfactory.
7, Japanese Patent (clear 57-075187) was once used the method aldehydes removal of trimeric cyanamide and oxymethylene polymerization.Concentration of formaldehyde can be reduced to 800mg/l, but raw material is rare, and cost is too high.Japanese Patent (clear 56-010391) adopts cyanamide calcium (CaCN
2, the popular name lime nitrogen) handle aldehyde-containing sewage, but the separation method of reaction product is not proposed.
8, present domestic vinylon plant as Sichuan vinylon plant, Chaohu, Anhui vinylon plant etc., all adopts biochemical process to handle aldehyde-containing sewage.The cyanide wastewater that China 3rd Design Inst., Ministry of Chemical Industry once at first tested with formaldehyde and fertilizer plant gas making workshop in 1979 carries out chemical reaction, generates formaldehyde cyanalcohol HO-CH
2-CN carries out biochemical treatment then.France then uses oxygenant oxidation formaldehyde cyanalcohols such as ozone, hydrogen peroxide, and Japanese Patent (clear 48-60454) provides biochemical process to handle the method for cyanalcohol.High-concentration formaldehyde can contain the following waste water of aldehyde 800mg/l so biochemical process can only be handled to production by biological toxigenicity restraining effect.
9, in addition, also have under the thermokalite effect, formaldehyde, self is aggregated into the treatment process (seeing Jilin applied chemistry institute of Chinese Academy of Sciences volume " polyoxymethylene " book, 1973) of polyol.But this method is difficult for water soluble resin is separated from waste water, thereby can not reduce the COD concentration in the water.Also have, require alkali concn more than 2～3%.
10, formaldehyde in water very easily autopolymerization become Paraformaldehyde 96, or being hydrolyzed into methylene glycol, most formaldehyde all do not exist with the form of unbound state, thereby physical separation method and physical chemistry separation method commonly used, as evaporation, extraction, distillation etc., all be difficult to obtain good separating effect.
Two, foregoing invention and patent though certain aldehydes removal effect is arranged, are applicable to specific occasions separately, have following subject matter:
1, some method, as wet oxidation process, distillation method, the equipment and technology condition and the investment of having relatively high expectations.
2, some method as chemical oxidation, is subjected to the interference of other coexistence components in the waste water, and use range is restricted.
3, some method,, discrimination method legal etc. as alkaline hot polymerization, all can not be from waste water reaction product isolated.Some method belongs to the conversion method of attenuating, can not reduce organic quantity in the waste water, can not reduce COD concentration in the waste water, even produces secondary pollution.
4, some method, for example biochemical process should not be handled the high density aldehyde-containing sewage, and the volumetric loading of handling is lower, needs bigger volume of equipment.
5, some method, as phenolic aldehyde polymerization, trimeric cyanamide polymerization, cyanalcohol method etc., main purpose is not aldehydes removal, on the contrary, or even adds aldehyde in waste water, to remove the bigger pollution components of another kind of toxicity.
6, in addition, above-mentioned treatment process exists more or less all that equipment is many, long flow path, investment height, chemical agent is expensive, processing efficiency is low.Waste water is produced secondary pollution, need certain temperature, pressure, air blast aeration condition, reaction product isolated from waste water fully, and carry out problem such as second stage employ.
Three, the methyne urea precipitator method aldehydes removal technology that proposes of the present invention, purpose is to improve existing aldehyde removal method, with enterprise obtain simply, efficient, low cost, blanket effect.
As far back as nineteen forty-seven～1948 year, existing abroad scholar mentions that in monograph formaldehyde and urea effect generate the reaction of cotton-shaped gel, promptly generate the reaction of methyne urea.This is the side reaction that should fight off and prevent in the aminoresin production process.This chemical reaction does not still have a practical use industrial so far.Effect of the present invention is:
The main reaction that (I) is used as side reaction as aldehydes removal is used, and the control reaction conditions, avoids being intended to generating the generation of the former main reaction of solubility aminoresin fully.
(II) is generalized to the former reaction that takes place in dilute solution and the waste water and carries out in the high density processing medium, and obtained reactivity completely.
(III) is generalized to the normal temperature scope with the former reaction of carrying out under hot conditions, and obtains speed of response faster.
Four, the reaction equation of utilization of the present invention is:
Five, implementation step of the present invention is: under the temperature condition of normal temperature or waste water boiling point, with acid the PH of waste liquid (or waste water) is transferred to appropriate value, in urine aldehyde ratio is that 1～2 ratio (weight ratio) adds solid urea, and slightly thing stirs, and reacts 1～2 hour, promptly generate methyne urea white precipitate, at this moment extremely neutral with alkali readjustment PH, solid-liquid separation is carried out in sedimentation or filtration then, the formaldehyde clearance is 97～99%, and the urea utilization ratio is more than 92%.
Six, implement the present invention, should control proper technical conditions:
1, urine aldehyde ratio:
Urine aldehyde weight ratio can change in 1～2 scope, requires to decide on the treatment scheme and the processing degree of depth.Urine aldehyde weight ratio is 1 o'clock, mainly generates two methyne ureas, and this reaction need higher temperature and stronger acidity, and the rate that reacts completely is lower slightly.Urine aldehyde weight ratio is 2 o'clock (and meal with wine adds surplus), mainly generates a methyne urea, and this reaction can be carried out under lower temperature and acidity, reaction completion rate height, and the formaldehyde residual concentration is low.
2, pH value
In the present invention, acid is used as catalyzer.The acid of using can be sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid or other inorganic acids.Though the use organic acid is effectively same, does not recommend to use organic acid, because it can increase the COD value in the waste water extraly.Take all factors into consideration, comparatively suitable to use 93～98% sulfuric acid.
The pH value of catalyzed reaction is in 1～5 scope, and (amounts to and add H during PH=2
2SO
45 grams per liters), acid consumption is little, and the reaction efficiency height is best pH value.
3, temperature
Evidence in 10～100 ℃ scope, all can obtain good effect.High temperature need consume heat energy, easily causes the volatilization of background component methyl alcohol in the waste water again, contaminate environment, thereby must adopt the Sealing Arrangement of taking back flow condenser, so, to be advisable with normal temperature, temperature is low excessively.Strengthen acid catalyst consumption (annotate: reaction heat can make water temperature raise 10～13 ℃, and reaction is had initiation).
4, the reaction times:
Reaction times is different variant because of conditions such as urine aldehyde ratio, temperature of reaction, pH values.In the time of 40 ℃, it is 1～2 hour.
5, stir
Only need after adding urea, slightly thing stirs, and can stop later on.But the reaction product during continuously stirring, sedimentation and separation property is preferable.
Seven, implement the present invention, direct polymerization method, indirect polymerized method and three kinds of approach of Precondensed UreaFormaldehyde Resin " set " method are arranged.
1, direct polymerization method is characterized in that urea and formaldehyde directly generate the methyne urea under acidic catalyst, sees reaction equation (1), (2), and implementation step is referring to example one, two, four.
2, indirect polymerized method, it is characterized in that urea and formaldehyde react earlier under neutrality or alkaline condition, generate solubility intermediate product methylolurea, formaldehyde is converted into involatile substance, then by distillation or evaporation, reclaim other volatile organic constituents in the waste water, as methyl alcohol, butanols, phenol etc.At this moment methylolurea is all stayed in the distillation kettle liquid, adds acid at last again in waste water, and PH is transferred to 1～2, makes water-soluble Oxymethurea change into insoluble methyne urea precipitation.Polymerization is undertaken by reaction equation (3), (4), and implementation step is referring to example three.
3, water-soluble Precondensed UreaFormaldehyde Resin " set " method, promptly under suitable acidity and temperature condition, the free methylol in the Precondensed UreaFormaldehyde Resin molecule of water-soluble low molecular weight, can dewater forms methyne key and ehter bond, thereby changed the dissolving resin performance, become the water-insoluble solid precipitation.When the formaldehyde of handling with the present invention in the aminoresin factory effluent, original solvability Precondensed UreaFormaldehyde Resin in the waste water (and resol resin etc.), all the mode with this " set " changes into insolubles, be separated simultaneously, thereby COD removal is higher.
Eight, implement the present invention, can adopt polymerization and two kinds of technical process of after polymerization method.
1, polymerization, promptly the weight ratio by urine and aldehyde is 2: 1, once throws sufficient urea, reaction product mainly is a methyne urea.One time the polymeric flow process is brief, but amount of urea is many, the processing costs height.
2, after polymerization method is 1 to add urea with urine aldehyde ratio earlier promptly, carries out the polymerization first time, and at this moment Fan Ying primary product is two methyne ureas.The filtering reaction throw out, residual formaldehyde in the analysis and filter mother liquor is 2 to add additional urea by urine aldehyde ratio then, carries out the polymerization second time.At this moment reaction product mainly is a methyne urea, reacts more thorough.Though after polymerization method flow process prolongs one times, amount of urea can reduce by 30%, referring to example two.
Nine, the present invention all is better than existing aldehyde removal method at aspects such as technico-economical comparison, the scope of application, implementation condition requirements, mainly is:
1, aldehydes removal reaction preference is strong, is not subjected to the interference of other background components in the waste water, thereby adaptability is strong, use range is wide.
2, reaction completion rate height, reaction product is separated fully, total COD clearance height.
3, flow process is brief, and tooling is simple, and is easy to implement, is convenient to promote.
4, starting material are easy to get, and expense is lower.
5, handle product the possibility of utilizing again, non-secondary pollution are arranged.
Ten, reaction product methyne urea of the present invention is insoluble infusibility white powder, and the about 189mg/l of solubleness is insoluble to hot water in cold water, diluted acid and diluted alkaline.Nitrogen content 32.68～36.7%, nothing is smelt, and chemical stability is strong.The methyne urea can be made slow-release fertilizer, or makes Precondensed UreaFormaldehyde Resin with special method dissolving back.
Be to implement example of the present invention below:
Example one:
The aminoresin factory effluent contains formaldehyde 29 λ 20mg/l.Get waste water 500ml, add sulfuric acid 2.45 grams, be warming up to 95 ℃, add urea 29 grams, stirring reaction 30 minutes is crossed filter solid, and residual formaldehyde 508mg/l in the waste water continues reaction 30 minutes, crosses filter solid, residual formaldehyde 393mg/l in the waste water.Formaldehyde clearance 98.6%.Urine aldehyde weight ratio is 1 for the 2(mol ratio).
Example two:
The aminoresin factory effluent contains formaldehyde 29120mg/l.Get waste water 300ml, enriching H
2SO
43.5ml, regulate PH=1, for the first time processing industry urea 10.8 grams, 12 ℃ of starting temperatures, stirred 10 minutes, arrest reaction half an hour is after the filtration, residual formaldehyde 5750mg/l in the waste water, add again in the filtrate and replenish urea 1.5 grams, stirred 10 minutes, reacted one hour, filter residual formaldehyde 250mg/l in the waste water of back, the total clearance of formaldehyde is 99%.Total urine aldehyde weight ratio is 0.7 for the 1.4(mol ratio).
Example three:
The aminoresin factory effluent contains formaldehyde 26400mg/l, methyl alcohol 60400mg/l, and butanols 54600mg/l gets waste water 500ml, regulates PH 〉=7, adds urea 35.5 grams, carries out precision fractional distillation, steams methyl alcohol and butanols, enriching H in the residuary water
2SO
42.5 gram, is incubated 2.5 hours, the elimination solid precipitation by PH=3.89 ℃.The about 10mg/l of residual formaldehyde in the waste water, the formaldehyde clearance is greater than 99.9%.
Example four:
The aminoresin factory effluent contains formaldehyde 26500mg/l, and contains methyl alcohol 6%, and butanols 5.5% also contains the small amounts of water soluble resin, and COD is 228700mg/l, gets waste water 780ml, is heated to 40 ℃, enriching H
2SO
43.5ml, urea 37.1 grams, stirring reaction 2 hours, filtering precipitate gets solid reactant 46 grams after the oven dry, the remaining aldehyde concentration 1296mg/l of filtrate, aldehyde clearance 95.1%.
Filtrate is then carried out precision fractional distillation, reclaims methyl alcohol and butanols, and final residual distillate volume is 418ml, and raffinate COD is 10250mg/l, the total clearance 97.3% of COD.
Claims (8)
1, a kind of chemical precipitation method is removed the method for formaldehyde, it is characterized in that: under acidic catalyst and suitable temperature condition, carry out polyreaction with the formaldehyde in urea and the waste water, generate water-fast precipitated product, carry out solid-liquid separation after, can from trade effluent, remove formaldehyde.
2, the described urea of claim 1, its consumption calculates by urine aldehyde weight ratio: urea: formaldehyde is between 1: 1～2: 1, and meal with wine adds surplus.Specifically, when adopting a polymerization technique, urine aldehyde weight ratio is 2: 1, and when adopting after polymerization technology, first set reaction is by adding urea, react according to residual formaldehyde concentration in the water after the preceding primary first-order equation for the second time at 1: 1, by adding additional urea at 2: 1.
3, the described acidic catalyst condition of claim 1 is PH=1～5, and is optimum with PH=2 especially.Regulating the used acid of PH, can be sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid or other inorganic acids, also can use organic acid, wherein comparatively suitable with 93～98% sulfuric acid.
4, the described proper temperature of claim 1 is 10～100 ℃, and is generally more suitable with normal temperature (20～40 ℃).
5, the urine aldehyde polyreaction described in the claim 1 is stirring or all can not finish under the stirring condition.Usually the stirring of summary thing gets final product after adding urea, can not make continuously stirring.
6, the urine aldehyde polyreaction described in the claim 1, its required time of reaction, conditions such as temperature were different and variant because of PH.At PH=2, under t=40 ℃ the condition, the reaction deadline is 1～2 hour.
7, synthetic according to claim 1 and claim 4, the feature of a polymerization technique are to be 2: 1 by urine aldehyde weight ratio, once throw sufficient urea in waste water, and primary first-order equation can obtain the aldehydes removal rate more than 97%.The purpose of after polymerization technology is to save amount of urea, it is characterized in that at first by urine aldehyde weight ratio being to add urea at 1: 1, carries out first set reaction, and the separating reaction precipitated product, the rate of aldehydes removal for the first time about 70～80%.Then according to residual formaldehyde concentration in the water behind the first set reaction, be to add additional urea at 2: 1 by urine aldehyde weight ratio, carry out the polymerization second time, to obtain aldehydes removal rate completely.Total urine aldehyde ratio of after polymerization is 1.4～1.5: 1.
8, according to claim 1, claim 3, the reaction that the aldehyde polymerization generates precipitated product is urinated in synthesizing of claim 4 and claim 7, and available direct method or indirect method realize.Direct method be characterised in that earlier aldehyde-containing sewage is transferred to acidity, again add urea, directly generate precipitated product.Indirect method is characterised in that elder generation transfers to neutrality or alkalescence with the PH of waste water, adds urea again, at this moment at first generates the water-soluble intermediate product of name meaning methylolurea, then with acidified aqueous solution, and regeneration infusible precipitate product.Indirect method aldehydes removal process application in advance with methods such as distillation or evaporations, is separated the occasion of other volatile organic constituents that coexist with formaldehyde in need from contain the aldehyde aqueous solution.Another kind of indirect method is the set method, is about to contain the waste water acidifying heating of low-molecular-weight soluble Precondensed UreaFormaldehyde Resin, makes wherein soluble resin become insoluble precipitate and separates from waste water.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 86107846 CN86107846A (en) | 1986-11-19 | 1986-11-19 | The methyne urea precipitator method are removed the formaldehyde in the trade effluent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 86107846 CN86107846A (en) | 1986-11-19 | 1986-11-19 | The methyne urea precipitator method are removed the formaldehyde in the trade effluent |
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| CN86107846A true CN86107846A (en) | 1988-06-01 |
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| CN 86107846 Pending CN86107846A (en) | 1986-11-19 | 1986-11-19 | The methyne urea precipitator method are removed the formaldehyde in the trade effluent |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0436082A2 (en) * | 1990-01-05 | 1991-07-10 | SàD-West-Chemie Gmbh | Separation of formaldehyde and/or dispersed colloids from production waste water, as well as usage of the generated precipitate |
| CN101348299B (en) * | 2008-09-05 | 2011-12-21 | 江苏扬农化工股份有限公司 | Glyphosate synthesized mother liquor processing method |
| CN102924510A (en) * | 2012-11-05 | 2013-02-13 | 沙隆达集团公司 | Method for recycling glyphosate and formaldehyde from glyphosate industrial wastewater |
| CN103435214A (en) * | 2013-09-09 | 2013-12-11 | 山东省泰和水处理有限公司 | Comprehensive treatment method for formaldehyde-containing acid wastewater |
| CN104108811A (en) * | 2014-06-27 | 2014-10-22 | 华南理工大学 | Treatment method for removing high concentration urea from wastewater |
| CN109111014A (en) * | 2017-06-26 | 2019-01-01 | 彤程化学（中国）有限公司 | A kind of resource utilization method of the aldehyde-containing sewage containing phenol |
-
1986
- 1986-11-19 CN CN 86107846 patent/CN86107846A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0436082A2 (en) * | 1990-01-05 | 1991-07-10 | SàD-West-Chemie Gmbh | Separation of formaldehyde and/or dispersed colloids from production waste water, as well as usage of the generated precipitate |
| EP0436082A3 (en) * | 1990-01-05 | 1991-09-25 | Sued-West-Chemie Gmbh | Separation of formaldehyde and/or dispersed colloids from production waste water, as well as usage of the generated precipitate |
| CN101348299B (en) * | 2008-09-05 | 2011-12-21 | 江苏扬农化工股份有限公司 | Glyphosate synthesized mother liquor processing method |
| CN102924510A (en) * | 2012-11-05 | 2013-02-13 | 沙隆达集团公司 | Method for recycling glyphosate and formaldehyde from glyphosate industrial wastewater |
| CN103435214A (en) * | 2013-09-09 | 2013-12-11 | 山东省泰和水处理有限公司 | Comprehensive treatment method for formaldehyde-containing acid wastewater |
| CN103435214B (en) * | 2013-09-09 | 2014-09-03 | 山东省泰和水处理有限公司 | Comprehensive treatment method for formaldehyde-containing acid wastewater |
| CN104108811A (en) * | 2014-06-27 | 2014-10-22 | 华南理工大学 | Treatment method for removing high concentration urea from wastewater |
| CN104108811B (en) * | 2014-06-27 | 2016-01-06 | 华南理工大学 | A kind for the treatment of process removing Coal Gas Washing Cycling Water urea |
| CN109111014A (en) * | 2017-06-26 | 2019-01-01 | 彤程化学（中国）有限公司 | A kind of resource utilization method of the aldehyde-containing sewage containing phenol |
| CN109111014B (en) * | 2017-06-26 | 2021-08-27 | 彤程化学（中国）有限公司 | Resource utilization method of phenol-containing and aldehyde-containing wastewater |
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