CN110002564A - The processing method of Chrome Tanning Wastewater - Google Patents
The processing method of Chrome Tanning Wastewater Download PDFInfo
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- CN110002564A CN110002564A CN201910415236.4A CN201910415236A CN110002564A CN 110002564 A CN110002564 A CN 110002564A CN 201910415236 A CN201910415236 A CN 201910415236A CN 110002564 A CN110002564 A CN 110002564A
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- waste water
- flocculant
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
- B01J20/26—Synthetic macromolecular compounds
- B01J20/264—Synthetic macromolecular compounds derived from different types of monomers, e.g. linear or branched copolymers, block copolymers, graft copolymers
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
- C02F1/56—Macromolecular compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F2001/007—Processes including a sedimentation step
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/20—Heavy metals or heavy metal compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/22—Nature of the water, waste water, sewage or sludge to be treated from the processing of animals, e.g. poultry, fish, or parts thereof
- C02F2103/24—Nature of the water, waste water, sewage or sludge to be treated from the processing of animals, e.g. poultry, fish, or parts thereof from tanneries
Abstract
The processing method of present invention offer Chrome Tanning Wastewater, belong to technical field of waste water processing, including grid impurity elimination, alkali is added to adjust, waste water sedimentation, acid adding is adjusted, and wherein waste water sedimentation is handled by flocculant, includes amphiprotic high-molecule chelated flocculating agent PDMAMDTC and chitosan derivative adsorbent material in above-mentioned flocculant；Chitosan derivative adsorbent material preparation step is as follows: dispersing triethylene tetramine and chitosan in acetic acid solution, adds crosslinking agent and reacted, then cleaned, is drying to obtain；Contain glutaraldehyde, triethanolamine and 3- mercaptopropionic acid in above-mentioned crosslinking agent.Reaction time needed for the processing method of Chrome Tanning Wastewater provided by the invention is short, and decontamination dust removal rate is high, and resource sufficiently recycles, and production and processing cost is effectively reduced；Flocculant used have the advantages that react completeness is high, surface can it is low, cationic degree is high, inherent viscosity is big, ionic adsorption capacity is big, net catches that ability is strong, flocculating settling characteristics are good.
Description
Technical field
The invention belongs to technical field of waste water processing, and in particular to the processing method of Chrome Tanning Wastewater.
Background technique
China is that maximum leatherware manufacture country, chrome tanning are an important procedure of leather production, and generation in the world
Unique process of source of heavy metal pollution, the Chrome Tanning Wastewater that this process generates is one of industrial wastewater difficult to deal with.Currently, leather
The wastewater flow rate that industry generates every year is about 80,000,000 t, accounts for the 1.6% of China's discharged volume of industrial waste water, it can be seen that, leather industry
It is quite serious to environment bring pollutant.
Processing, tanning, neutralization and the dyeing and fat-liquoring of a large amount of chromate waste water from raw material skin etc. four is discharged in leather industry
Process, wherein a large amount of chrome tanning agents used in tanning processes are main sources, chrome tanning agent be used for the main tan of rawhide, retanning and
To the fixation of other chemical materials when post-production.Chrome tanning technology has easy to operate, quality stabilization, cheap advantage,
The optimal tannery of cost performance, thus be more than 90% leather-making enterprises all use this method carry out leather production.However
In the tanning stage, rawhide is limited to the absorptivity of chrome tanning agent (about 60%), and the content of chromium is up to 1000 in waste water after tanning
~3000mg/L, content is significantly larger than the concentration of emission limit value (< 1.5mg/L) of chromium in waste water, in addition, this kind of waste water also has
Have the characteristics that water is big, water-quality constituents is complicated, not only the organic matters such as including dyestuff, but also contains chloride and sulfate species, and
The daily drain time of leather-making waste water is uncertain, and instantaneity is strong, causes sewage quality under-represented, so that sewage is difficult.
Chrome Tanning Wastewater mainly contains the organic matter of chromium and high concentration, and wherein chromium is with Cr3+Form based on, content is in 3~6g/
L, Cr6+Content it is generally very low；COD is 4~8g/L.Suspended matter and high organic content in waste water, coloration is big and color not
Fixed, biodegradability is bad.The chromate waste water for discharging high concentration, not only results in water pollution, the health of harmful to human,
It will cause the resource of waste.Therefore, it needs to research and develop practicable method and it is effectively administered.So far, both at home and abroad
A variety of Chrome Tanning Wastewater processing methods are had developed, such as alkaline precipitation, ion-exchange, electrolysis method, absorption method, chemical flocculation
Deng.Compared with other methods, and chemical method chelate precipitation has the advantage that due to forming insoluble stable chelate,
High treating effect can make heavy metal ion be reduced to very low level；Treatment process is simple, and chelating agent only need to be added into waste water,
Agitated mixing, then precipitation and separation；Efficiently, it is suitable for extensive heavy metal containing wastewater treatment；Processing cost is lower.Therefore, by
The attention of heavy metal containing wastewater treatment circle.
Heavy metal ion is handled using chelate precipitation, is by the functional group and a huge sum of money on chelator molecule
Belong to ion chelating and form insoluble salt, or curl macromolecular chain to form wadding body by charge neutrality, enables heavy metal ion
Separation.Currently, the research of heavy metal chelant, is concentrated mainly on the organic matter containing coordination atoms such as N, P, O, S, can be divided into small
Molecule heavy metal chelant and high-molecular chelating agent two major classes.And use small molecule heavy metal chelating flocculant process chromate waste water
The particle of formation is smaller, and settling property is poor, is typically necessary plus (wadding) is helped to coagulate agent, and small molecule precipitating reagent is easy to remain in
It handles in water, causes secondary pollution.It is generated in electricity after chelation group is in conjunction with heavy metal ion in traditional high-molecular chelating agent
And effect, it curls macromolecular chain and generates flocculation, imitated than small molecule heavy metal precipitator with better flocculating setting
The residual quantity of fruit, flocculant is also less, but all there is the case where steric hindrance or Space mismatching, the micro-floccule resulted in
With superfluous negative electrical charge, the repulsion of identical charges makes micro-floccule be difficult to be formed and the big floc sedimentation of long great achievement, and flocculating settling characteristics are poor,
It is bad to the removal effect of heavy metal.Therefore the positive charge that appropriate amount is introduced in macromolecular chain is then conducive to neutralize wadding body shape
At the negative electrical charge generated in the process, to be conducive to the generation and growth of micro-floccule, heavy metal ions in wastewater is gone in raising
Except the settling property of effect and wadding body.
Summary of the invention
The purpose of the present invention is to provide a kind of reaction time is short, decontamination dust removal rate is high, resource sufficiently recycles, has
The processing method for reducing the Chrome Tanning Wastewater of production and processing cost is imitated, wherein flocculant used has reaction completeness height, surface
Energy is low, cationic degree is high, inherent viscosity is big, ionic adsorption capacity is big, net catches the advantage that ability is strong, flocculating settling characteristics are good.
The technical solution that the present invention is taken to achieve the above object are as follows:
A kind of flocculant is handled for Chrome Tanning Wastewater, includes chitosan derivative adsorbent material in the flocculant；Above-mentioned shell is poly-
The derivative adsorbent material of sugar is prepared by following steps: being dispersed triethylene tetramine and chitosan in acetic acid solution, is added friendship
Connection agent is reacted, and is then cleaned, is drying to obtain；Contain glutaraldehyde, triethanolamine and 3- mercaptopropionic acid in above-mentioned crosslinking agent.It
Right high molecular polymer chitosan is a kind of aminated polysaccharide with cationic polyelectrolyte characteristic, and good biocompatibility, acid
Property under the conditions of can with anionic compound occur ion exchange, can be used for adsorbing and agglomerating flocculation process, to heavy metal
Or organic pollutant has numerous adsorption sites, before having a wide range of applications chitosan derivative material in terms of the wastewater treatment
Scape.
Preferably, chitosan derivative adsorbent material is prepared by step in detail below: by weight the ratio for being 1:4~5
Example takes triethylene tetramine and chitosan, 20~30 times of amounts is then added, the acetic acid solution that concentration is 2~3%, and stir using ultrasound
20~30min of mixing is mixed, the crosslinking agent of chitosan weight 0.15~0.2% is added, is placed in the water-bath that temperature is 45~50 DEG C
Middle constant temperature is stirred to react 2~3h, after fully reacting use washes of absolute alcohol, be drying to obtain, in above-mentioned crosslinking agent containing glutaraldehyde,
Triethanolamine and 3- mercaptopropionic acid, wherein the weight accounting of triethanolamine and 3- mercaptopropionic acid in crosslinking agent be respectively 2.1~
3.1wt% and 1.7~2.7wt%.The crosslinking agent of addition introduces amido, aldehyde radical, sulfydryl and carboxyl into system, wherein aldehyde radical
And it can be crosslinked with the amido in system, the hydroxyl in chitosan can promote mercapto with the hydroxyl condensation in chitosan
Valence link power is formed between base and amido, carboxyl, finally under Coulomb force, lone pair electrons and electrostatic interaction, forms similar net
The structure of lattice, by chitosan and triethylene tetramine bridge joint at an entirety, this structure keeps the structure of product more loose, surface
Can reduce, thus increase with the touch opportunity of Pollutants in Wastewater, be conducive to carry out net to the pollutant in waste water to catch, increase is gone
Miscellaneous dirty removal capacities, while hole can also be used and carry out ionic adsorption, increase the ionic adsorption capacity of product.
The invention also discloses a kind of processing methods of Chrome Tanning Wastewater, including grid impurity elimination, and alkali is added to adjust, waste water sedimentation,
Acid adding is adjusted, and wherein waste water sedimentation is handled by flocculant, includes amphiprotic high-molecule chelated flocculating agent in above-mentioned flocculant
PDMAMDTC and chitosan derivative adsorbent material.
Preferably, grid goes to use mixedly mesh screen to be 30~50 mesh, hydraulic detention time is 2~4h.Using grid to waste water
It is pre-processed, waste water flow velocity can be slowed down, while can stop and remove the granular dirt of water part (outstanding by grid
Floating object and floating material), smaller fibrous matter, grease and hair etc., effectively play protection subsequent handling equipment and run well and subtract
The effect of light processing load.
Preferably, plus alkali adjust be into waste water after impurity elimination add 3.8~4.3kg/t waste water alkaline solution sunk
Shallow lake processing, and the pH value of waste water is adjusted to 7~9.Wastewater pH is adjusted to alkalinity, can make in waste water partially free metal from
Son forms insoluble precipitating, removes a part of metal ion in conjunction with hydroxyl, trivalent chromic ion especially therein, energy
Form chromium hydroxide precipitation.
Further preferably, alkaline solution in sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate extremely
Few one kind.
Further preferably, it after adding alkali to adjust the precipitating recycling generated, can be back in leather-making technology by acidolysis.It generates
Precipitating based on chromium hydroxide is reduced into chromic salts after acidleach is handled, and can be used as supplement and is back in chrome tanning operation,
Both resource can be made full use of, chromium discharge is reduced, and alleviates subsequent wastewater treatment burden.
Preferably, waste water settlement treatment step are as follows: after adding flocculant into waste water, in the stirring of 80~100r/min
After reacting 20~30min under speed, 0.5~1h is stood, supernatant is then sent into conditioning tank, after lower sediment filtering, filtrate
It is sent into conditioning tank, filter residue is sent into sludge drying pond.The high polymer coagulant added into waste water can utilize charge neutrality effect and frame
Bridge suction-operated, jointly remaining Cr VI, trivalent chromium and other metal ions in flocculation waste water, and rapid subsidence, wadding
Body is coarse and closely knit, can decolourize, reduce turbidity, removal COD etc., treatment effect is excellent.
Preferably, the dosage of flocculant be 28~35L/m2, wherein amphiprotic high-molecule chelated flocculating agent PDMAMDTC and
The weight ratio of chitosan derivative adsorbent material is 2.1~2.6:1.3.
Preferably, amphiprotic high-molecule chelated flocculating agent PDMAMDTC is prepared by following steps: taking two allyl of dimethyl
Ammonium chloride and acrylamide monomer are caused by initiator and generate copolymer p (DMDAAC-AM)；Be then respectively adding formaldehyde and
Polyamines is linked, and aminated copolymer is obtained；Finally under alkaline environment, aminated copolymer and carbon disulfide is made to react life
At PDMAMDTC.Basic framework is constituted through causing copolymerization with dimethyl diallyl ammonium chloride and acrylamide, then in alkalinity
Under environment, copolymer and formaldehyde and polyamines occur Mannich and reacts, by the macromolecular chain of polyamines access copolymer, it is subsequent and
Carbon disulfide carries out xanthan acidification response, accesses xanthogen anion, and reaction completeness is higher, is able to achieve in molecule and both contained
Quaternary ammonium cations, and contain xanthan acid radical anion, to achieve the purpose that both sexes are copolymerized, effectively neutralized because of steric hindrance or
The phenomenon of wadding body negative electrical charge surplus caused by Space mismatching, is conducive to the generation and growth of wadding body, effectively increases to waste water
The removal effect of middle heavy metal ion and the settling property of wadding body.
Further preferably, the inherent viscosity of copolymer p (DMDAAC-AM) is 130~150mL/g, cationic degree 30.5
~35.5%.
Further preferably, specific preparation process is as follows by amphiprotic high-molecule chelated flocculating agent PDMAMDTC:
Step 1,0.48~0.51:1 takes dimethyl diallyl ammonium chloride and acrylamide monomer in molar ratio, and addition is gone
Ionized water dissolution is made into the mixed solution that mass concentration is 21~25%, then passes to nitrogen flooding 25~35min of oxygen, then to mixing
The initiator of 0.11~0.17wt% is added in solution, 1.5~2.5h is reacted at a temperature of 60~65 DEG C, is rinsed with methanol
Afterwards, copolymer p (DMDAAC-AM) is obtained；
Step 2, deionized water is added in gained copolymer into step 1, is made into the solution that mass concentration is 11~15%,
Adjusting pH value of solution is 10~11, and formaldehyde is first added and reacts 35~45min at 40~50 DEG C, adds polyamines at 45~50 DEG C
1.5~2h is reacted, obtains aminated copolymer, above-mentioned formaldehyde and polyamines are acrylamide by weight: formaldehyde: polyamines=1:
The ratio of 0.68~0.72:1.15~1.25 is added；
Step 3, deionized water is added into aminated copolymer, be made into mass concentration be 5~8% solution, successively plus
Enter sodium hydroxide and carbon disulfide, prior to 25~35 DEG C at react 1.5~2h after, at 45~50 DEG C react 1~1.5h, then
It after anhydrous propanone precipitating, can obtain, above-mentioned reactant is by weight N atom in polyamines: sodium hydroxide: carbon disulfide=1:
The ratio of 1.6~2.1:2.1~2.8 is added.
Still further preferably, initiator used is ammonium persulfate, potassium peroxydisulfate or redox initiator in step 1；Step
Polyamines used is selected from least one of ethylenediamine, diethylenetriamine, triethylene tetramine, tetraethylenepentamine in rapid 2.
Preferably, acid adding regulating step are as follows: add acidic liquid into the clear liquid being sent into conditioning tank, adjust clear liquid
After pH is neutral, the waste water for being up to discharge standard is discharged.Waste water after processing can be with direct emission, can also be with reuse
In leather-making technology, resource is taken full advantage of, has saved production cost.
The invention has the benefit that
1) made amphiprotic high-molecule chelated flocculating agent is that positive charge is introduced in macromolecular chain in the present invention, is effectively neutralized
Wadding body forms the negative electrical charge of rear surplus, and free radical quantity is more, diffusion rate height, chain tra nsfer and stopping of chain rate in system when preparation
It reduces, reaction completeness is high, and product has higher cationic degree, inherent viscosity and relative molecular mass, is conducive to wadding body
Generate and growth, wadding body is coarse and closely knit, can rapid subsidence it is complete, effectively improve to heavy metal ions in wastewater removal effect
The settling property of fruit and wadding body；
2) chitosan derivative adsorbent material short texture used in the present invention, surface can be low, can be to the heavy metal in waste water
Or organic pollutant carries out net and catches, while the hole in structure and numerous adsorption site progress ionic adsorptions can also be used, and produces
The ionic adsorption capacity of object is big, and impurity elimination dirty removal capacities are strong；
3) composite flocculant used integrates chelated metal ions, absorption and flocculation ability in the present invention, is applicable in model
It encloses extensively, is not required to separately add flocculation aid, can be reacted at normal temperature with each metal ion species in waste water, and generate not soluble in water and property
Can stable sediment, wadding body is coarse and closely knit, can rapid subsidence it is complete, treatment effect is excellent, reach decoloration, reduce it is turbid
The multiple efficacies such as degree, removal COD, and effectively saved processing cost；
4) Chrome Tanning Wastewater obtains that processing technological flow is simple, and the reaction time is short in the present invention, and removal efficiency is high, at the same to chromium from
Son is recycled, and can not only be reduced subsequent processing burden, be also saved production cost, realize clean manufacturing, follow
Ring economy.
Present invention employs above-mentioned technical proposals to provide the processing method of Chrome Tanning Wastewater, compensates for the deficiencies in the prior art,
Reasonable design, easy operation.
Detailed description of the invention
Fig. 1 is flow diagram of the invention.
Specific embodiment
Technical solution of the present invention is described in further detail below in conjunction with specific embodiment and attached drawing:
Embodiment 1:
A kind of flocculant is handled for Chrome Tanning Wastewater, includes chitosan derivative adsorbent material in the flocculant；Above-mentioned shell is poly-
The derivative adsorbent material of sugar is prepared by following steps: being dispersed triethylene tetramine and chitosan in acetic acid solution, is added friendship
Connection agent is reacted, and is then cleaned, is drying to obtain；Contain glutaraldehyde, triethanolamine and 3- mercaptopropionic acid in above-mentioned crosslinking agent.It
Right high molecular polymer chitosan is a kind of aminated polysaccharide with cationic polyelectrolyte characteristic, and good biocompatibility, acid
Property under the conditions of can with anionic compound occur ion exchange, can be used for adsorbing and agglomerating flocculation process, to heavy metal
Or organic pollutant has numerous adsorption sites, before having a wide range of applications chitosan derivative material in terms of the wastewater treatment
Scape.
Chitosan derivative adsorbent material is prepared by step in detail below: taking triethylene by weight for the ratio of 1:4.5
Then 20 times of amounts are added, the acetic acid solution that concentration is 2%, and mix 25min using being stirred by ultrasonic in tetramine and chitosan, then plus
The crosslinking agent for entering chitosan weight 0.16% is placed in constant temperature in the water-bath that temperature is 45 DEG C and is stirred to react 3h, uses after fully reacting
Washes of absolute alcohol is drying to obtain, and glutaraldehyde, triethanolamine and 3- mercaptopropionic acid is contained in above-mentioned crosslinking agent, wherein three ethyl alcohol
The weight accounting of amine and 3- mercaptopropionic acid in crosslinking agent is respectively 2.3wt% and 1.9wt%.The crosslinking agent of addition is into system
Amido, aldehyde radical, sulfydryl and carboxyl are introduced, wherein aldehyde radical can be with the hydroxyl condensation in chitosan, and can be with the amine in system
Base crosslinks, the hydroxyl in chitosan can promote between sulfydryl and amido, carboxyl formed valence link power, finally Coulomb force,
Under lone pair electrons and electrostatic interaction, the structure of similar grid is formed, chitosan and triethylene tetramine bridge joint is whole at one
Body, this structure keep the structure of product more loose, and surface can reduce, thus increase the touch opportunity with Pollutants in Wastewater,
Be conducive to carry out net to the pollutant in waste water to catch, increase impurity elimination dirty removal capacities, while hole can also be used and carry out ionic adsorption,
Increase the ionic adsorption capacity of product.
A kind of processing method of Chrome Tanning Wastewater, including grid impurity elimination, add alkali to adjust, and waste water sedimentation, acid adding is adjusted, wherein giving up
Water sedimentation is handled by flocculant, includes amphiprotic high-molecule chelated flocculating agent PDMAMDTC and chitosan in above-mentioned flocculant
Derivative adsorbent material.
Grid goes to use mixedly mesh screen to be 30 mesh, hydraulic detention time 2.5h.Waste water is pre-processed using grid, it can be with
Slow down waste water flow velocity, at the same by grid can stop and remove the granular dirt of water part (suspended matter and floating material),
Smaller fibrous matter, grease and hair etc. effectively play the normal operation of protection subsequent handling equipment and mitigate the work of processing load
With.
Adding alkali to adjust is the alkaline solution progress precipitation process of 3.8kg/t waste water to be added into waste water after impurity elimination, and will give up
The pH value of water is adjusted to 7.Wastewater pH is adjusted to alkalinity, can make metal ion partially free in waste water in conjunction with hydroxyl,
Insoluble precipitating is formed, a part of metal ion is removed, it is heavy to form chromium hydroxide for trivalent chromic ion especially therein
It forms sediment.Above-mentioned alkaline solution is selected from least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, this reality
It applies and selects sodium hydroxide in example.
After adding alkali to adjust the precipitating recycling generated, it can be back in leather-making technology by acidolysis.Generate with chromium hydroxide
Based on precipitating be reduced into chromic salts after acidleach is handled, can be used as supplement be back to chrome tanning operation in, both can be abundant
Using resource, chromium discharge is reduced, and alleviates subsequent wastewater treatment burden.
Waste water settlement treatment step are as follows: after adding flocculant into waste water, reacted under the mixing speed of 90r/min
After 20min, 1h is stood, supernatant is then sent into conditioning tank, after lower sediment filtering, filtrate is sent into conditioning tank, and filter residue is sent into
Sludge drying pond.The high polymer coagulant added into waste water can utilize charge neutrality effect and bridge formation suction-operated, common to flocculate
Remaining Cr VI, trivalent chromium and other metal ions in waste water, and rapid subsidence, wadding body is coarse and closely knit, can decolourize,
Turbidity, removal COD etc. are reduced, treatment effect is excellent.
The dosage of flocculant is 30L/m2, wherein amphiprotic high-molecule chelated flocculating agent PDMAMDTC and chitosan derivative absorption
The weight ratio of material is 2.1:1.3.
Amphiprotic high-molecule chelated flocculating agent PDMAMDTC pass through following steps prepare: take dimethyl diallyl ammonium chloride and
Acrylamide monomer is caused by initiator and generates copolymer p (DMDAAC-AM)；It is then respectively adding formaldehyde and polyamines carries out chain
It connects, obtains aminated copolymer；Finally under alkaline environment, reacts aminated copolymer and carbon disulfide and generate
PDMAMDTC.Basic framework is constituted through causing copolymerization with dimethyl diallyl ammonium chloride and acrylamide, then in alkaline ring
Under border, copolymer and formaldehyde and polyamines occur Mannich and reacts, subsequent and two by the macromolecular chain of polyamines access copolymer
Nitric sulfid carries out xanthan acidification response, accesses xanthogen anion, realizes and not only contains quaternary ammonium cations in molecule, but also contains Huang
Former acid radical anion, thus achieve the purpose that both sexes are copolymerized, wadding caused by effectively having neutralized because of steric hindrance or Space mismatching
The phenomenon of body negative electrical charge surplus, is conducive to the generation and growth of wadding body, effectively increases the removal to heavy metal ions in wastewater
The settling property of effect and wadding body.
Specific preparation process is as follows by amphiprotic high-molecule chelated flocculating agent PDMAMDTC:
Step 1,0.48:1 takes dimethyl diallyl ammonium chloride and acrylamide monomer in molar ratio, and deionized water is added
Dissolution is made into the mixed solution that mass concentration is 22.5%, then passes to nitrogen flooding oxygen 35min, then be added into mixed solution
The initiator of 0.13wt% reacts 2h at a temperature of 60 DEG C, after being rinsed with methanol, obtains copolymer p (DMDAAC-AM)；
Step 2, deionized water is added in gained copolymer into step 1, is made into the solution that mass concentration is 12%, adjust
PH value of solution is 10, and formaldehyde is first added and reacts 35min at 45 DEG C, adds polyamines and reacts 1.5h at 45 DEG C, obtain aminated
Copolymer, above-mentioned formaldehyde and polyamines are acrylamide by weight: formaldehyde: the addition of polyamines=1:0.68:1.19 ratio；
Step 3, deionized water is added into aminated copolymer, is made into the solution that mass concentration is 7.5%, sequentially adds
Sodium hydroxide and carbon disulfide, prior to 30 DEG C at react 1.5h after, react 1.5h at 45 DEG C, then with anhydrous propanone precipitating
Afterwards, can obtain, above-mentioned reactant is by weight N atom in polyamines: sodium hydroxide: carbon disulfide=1:1.7:2.3 ratio adds
Add.
Initiator used is ammonium persulfate, potassium peroxydisulfate or redox initiator in above-mentioned steps 1, is selected in the present embodiment
Use ammonium persulfate；In step 2 polyamines used in ethylenediamine, diethylenetriamine, triethylene tetramine, tetraethylenepentamine at least
One kind selecting triethylene tetramine in the present embodiment.
Acid adding regulating step are as follows: add acidic liquid into the clear liquid being sent into conditioning tank, adjust the pH of clear liquid as neutrality
Afterwards, the waste water for being up to discharge standard is discharged.Waste water after processing can also be back to process hides work with direct emission
In skill, resource is taken full advantage of, has saved production cost.
Embodiment 2:
The processing method of Chrome Tanning Wastewater, specifically includes the following steps:
1) grid impurity elimination: Chrome Tanning Wastewater is subjected to impurity elimination processing by grid, mesh screen used is 40 mesh, hydraulic detention time
For 3h；
2) plus alkali is adjusted: the sodium hydroxide solution for adding 4.2kg/t waste water after to impurity elimination in waste water carries out precipitation process, and
The pH value of waste water is adjusted to 8, after then recycling the precipitating of generation, leather-making technology can be back to by acidolysis；
3) waste water settles: 33L/m is added into waste water2After flocculant, 30min is reacted under the mixing speed of 80r/min
Afterwards, 1h is stood, supernatant is then sent into conditioning tank, after lower sediment filtering, filtrate is sent into conditioning tank, and it is dry that filter residue is sent into sludge
Change pond, the weight of the amphiprotic high-molecule chelated flocculating agent PDMAMDTC and chitosan derivative adsorbent material that contain in above-mentioned flocculant
Than for 2.5:1.3；
4) acid adding is adjusted: acidic liquid is added into the clear liquid being sent into conditioning tank, it, will after adjusting the pH of clear liquid as neutrality
The waste water for reaching discharge standard is discharged, or is back to leather-making technology.
Specific preparation process is as follows by amphiprotic high-molecule chelated flocculating agent PDMAMDTC used in above-mentioned flocculant:
Step 1,0.5:1 takes dimethyl diallyl ammonium chloride and acrylamide monomer in molar ratio, and deionized water is added
Dissolution is made into the mixed solution that mass concentration is 23.5%, then passes to nitrogen flooding oxygen 30min, then be added into mixed solution
The ammonium persulfate of 0.16wt% reacts 1.5h at a temperature of 65 DEG C, after being rinsed with methanol, obtains copolymer p (DMDAAC-
AM)；
Step 2, deionized water is added in gained copolymer into step 1, is made into the solution that mass concentration is 11.5%, adjust
Saving pH value of solution is 10.5, and formaldehyde is first added and reacts 40min at 45 DEG C, adds triethylene tetramine and reacts 2h at 50 DEG C, obtain
To aminated copolymer, above-mentioned formaldehyde and polyamines are acrylamide by weight: formaldehyde: polyamines=1:0.72:1.23 ratio
Addition；
Step 3, deionized water is added into aminated copolymer, is made into the solution that mass concentration is 5.5%, sequentially adds
Sodium hydroxide and carbon disulfide, prior to 35 DEG C at react 2h after, react 1.25h at 50 DEG C, then with after anhydrous propanone precipitating,
It can obtain, above-mentioned reactant is by weight N atom in polyamines: sodium hydroxide: carbon disulfide=1:2.1:2.5 ratio addition.
Chitosan derivative adsorbent material used passes through step in detail below and prepares in above-mentioned flocculant: by weight being 1:5
Ratio take triethylene tetramine and chitosan, then be added 30 times amount, concentration be 3% acetic acid solution, and using ultrasonic agitation
30min is mixed, the crosslinking agent of chitosan weight 0.2% is added, constant temperature in the water-bath that temperature is 50 DEG C is placed in and is stirred to react
2.5h uses washes of absolute alcohol, is drying to obtain after fully reacting, glutaraldehyde, triethanolamine and 3- mercapto are contained in above-mentioned crosslinking agent
Base propionic acid, wherein the weight accounting of triethanolamine and 3- mercaptopropionic acid in crosslinking agent is respectively 2.8wt% and 2.5wt%.
Embodiment 3:
In the present embodiment, the preparation of amphiprotic high-molecule chelated flocculating agent PDMAMDTC used in flocculant is optimized,
Specific Optimized Measures are as follows:
Step 1,0.5:1 takes dimethyl diallyl ammonium chloride and acrylamide monomer in molar ratio, and deionized water is added
Dissolution is made into the mixed solution that mass concentration is 23.5%, then passes to nitrogen flooding oxygen 30min, then be added into mixed solution
The ammonium persulfate of 0.16wt%, 0.04% sodium oxalate and 0.02% dimethyl sulfoxide, react 1.5h at a temperature of 65 DEG C,
After being rinsed with methanol, copolymer p (DMDAAC-AM) is obtained, as the cationic degree of copolymerization product is continuously increased, due to cation
Three-dimensional effect and the electrical charge rejection effect formed after addition is also enhancing, and can reduce reactivity of the monomer in system, also press down
The sustainable growth of polymerizate inherent viscosity has been made, sodium oxalate and dimethyl sulfoxide is added, two kinds of monomers has been can trigger and generates more
More free radical participates in reaction, and free radical is constantly spread and is added in reaction system, free radical quantity and diffusion rate
Increase, dramatically increase the collision probability of two kinds of monomers, so that polymerization is continued for carrying out, while vacation can be formed between cation again
Property replace, reduce the free energy of cationic institute's band, reaction is able to persistently carry out towards the direction of polymerization, chain tra nsfer and stopping of chain
Rate reduce, reaction completeness is high so that the existing higher cationic degree of copolymer has biggish inherent viscosity again, increasing
Add the relative molecular mass of copolymer, and then increases the flocculating settling characteristics of final product；
Step 2, deionized water is added in gained copolymer into step 1, is made into the solution that mass concentration is 11.5%, adjust
Saving pH value of solution is 10.5, and formaldehyde is first added and reacts 40min at 45 DEG C, adds triethylene tetramine and reacts 2h at 50 DEG C, obtain
To aminated copolymer, above-mentioned formaldehyde and polyamines are acrylamide by weight: formaldehyde: polyamines=1:0.72:1.23 ratio
Addition；
Step 3, deionized water is added into aminated copolymer, is made into the solution that mass concentration is 5.5%, sequentially adds
Sodium hydroxide and carbon disulfide, prior to 35 DEG C at react 2h after, react 1.25h at 50 DEG C, then with after anhydrous propanone precipitating,
It can obtain, above-mentioned reactant is by weight N atom in polyamines: sodium hydroxide: carbon disulfide=1:2.1:2.5 ratio addition.
The present embodiment is to optimize test on the basis of embodiment 2, other steps and embodiment 2 are consistent, carries out chromium
The processing of tan waste water.
Embodiment 4:
In the present embodiment, chitosan derivative adsorbent material used passes through step in detail below and prepares in flocculant: by weight
Triethylene tetramine and chitosan are taken than the ratio for 1:5,30 times of amounts are then added, the acetic acid solution that concentration is 3%, and using super
Sound stirs and evenly mixs 30min, adds the glutaraldehyde of chitosan weight 0.2%, is placed in constant temperature stirring in the water-bath that temperature is 50 DEG C
2.5h is reacted, washes of absolute alcohol is used after fully reacting, is drying to obtain, i.e., is not added with triethanolamine and 3- in above-mentioned preparation process
Mercaptopropionic acid.
The present embodiment is to compare test on the basis of embodiment 2, other steps and embodiment 2 are consistent, carries out chromium
The processing of tan waste water.
Embodiment 5:
The present embodiment is to compare test on the basis of embodiment 2, and wherein flocculating setting step is only single with flocculant
One includes amphiprotic high-molecule chelated flocculating agent PDMAMDTC, and chitosan derivative adsorbent material, other steps and embodiment 2 is not used
Unanimously, the processing of Chrome Tanning Wastewater is carried out.
Embodiment 6:
The present embodiment is to compare test on the basis of embodiment 2, and wherein flocculating setting step is only single with flocculant
One includes chitosan derivative adsorbent material, and amphiprotic high-molecule chelated flocculating agent PDMAMDTC, other steps and embodiment 2 is not used
Unanimously, the processing of Chrome Tanning Wastewater is carried out.
Embodiment 7:
Amphiprotic high-molecule chelated flocculating agent performance measurement
1) measurement of inherent viscosity: using 1mol/L sodium chloride solution as solvent, the P (DMDAAC-AM) of synthesis is dissolved in
Wherein, it is subsequently placed in 30 DEG C of water bath with thermostatic control, using its delivery time of determination of ubbelohde viscometer, the ratio between with the solvent delivery time
Relative viscosity is calculated, then calculates its inherent viscosity [η] as follows:
In formula: c- solution concentration, ηspPolymer solution specific viscosity, ηrRelative viscosity.
2) measurement of cationic degree: using the C1 of chloride ion-selective electrode method measurement and cation balance-Content, i.e.,
For the content of cation group in P (DMDAAC-AM) strand.
The embodiment 1,2 and 3 of phase homogenous quantities is taken to prepare the copolymer p that flocculant PDMAMDTC step 1 obtains respectively
(DMDAAC-AM), the measurement of inherent viscosity and cationic degree, measurement result such as the following table 1 are carried out.
The inherent viscosity and cationic degree measurement result of 1 copolymer p of table (DMDAAC-AM)
| Inherent viscosity mL/g | Cationic degree mol% | |
| Embodiment 1 | 132 | 31.14 |
| Embodiment 2 | 138 | 30.86 |
| Embodiment 3 | 146 | 31.63 |
As seen from the above table, after optimization, the inherent viscosity and sun of made copolymer p (DMDAAC-AM) in embodiment 3
Ion degree is all increased compared with the gained of embodiment 2, and inherent viscosity increases, and the relative molecular mass of product also increases, to metal from
The flocculating effect of son also will increase；Cationic degree increase illustrates that the conversion ratio of reaction increases, and reacts and carries out towards the direction of copolymerization,
Optimization is achieved the purpose that.
Embodiment 8:
Chrome Tanning Wastewater processing test
At the wastewater treatment center of certain tannery, the processing method being respectively adopted in embodiment 2~6 is useless to same a collection of chrome tanning
Water is handled, and homologous waste water is randomly divided into 5 groups, and every group 2 parallel, after to be processed, the waste water of discharge is taken to be examined
It surveys, every Testing index such as table 2.
2 Chrome Tanning Wastewater of table handles test result
As seen from the above table, comprehensive all data, the processing result of the embodiment 3 by optimization is optimal, and embodiment 2 is taken second place,
The result of embodiment 4 is slightly worse compared with embodiment 2, is primarily due to prepare chitosan derivative adsorbent material crosslinking agent in embodiment 4
In be not added with triethanolamine and 3- mercaptopropionic acid so that product property is declined slightly；The comparison discovery of embodiment 5 and 6, chitosan spread out
Removal effect of the raw adsorbent material in COD, turbidity and coloration is more significant, and amphiprotic high-molecule chelated flocculating agent PDMAMDTC
Removal effect on total chromium, suspended matter and SS becomes apparent, and when the two is used together, synergy is played, to Chrome Tanning Wastewater
Treatment effect can be optimal.
The prior art of routine techniques dawn known to those skilled in the art in above-described embodiment, therefore herein no longer in detail
It repeats.
The above embodiments are only used to illustrate the present invention, and not limitation of the present invention, the ordinary skill people of this field
Member can also make a variety of changes and modification without departing from the spirit and scope of the present invention.Therefore, all equivalent
Technical solution also belong to scope of the invention, scope of patent protection of the invention should be defined by the claims.
Claims (10)
1. a kind of flocculant is handled for Chrome Tanning Wastewater, it is characterised in that: including chitosan derivative adsorbent material；
The chitosan derivative adsorbent material is prepared by following steps: dispersing acetic acid solution for triethylene tetramine and chitosan
In, it adds crosslinking agent and is reacted, then cleaned, is drying to obtain；
Contain glutaraldehyde, triethanolamine and 3- mercaptopropionic acid in the crosslinking agent.
2. a kind of flocculant according to claim 1, it is characterised in that: the preparation of the chitosan derivative adsorbent material walks
In rapid, the weight ratio of raw material triethylene tetramine and chitosan is 1:4 ~ 5, and the concentration of acetic acid solution is 2 ~ 3%, the addition of crosslinking agent
Amount is the 0.15 ~ 0.2% of chitosan weight, and wherein the weight accounting of triethanolamine and 3- mercaptopropionic acid in crosslinking agent is respectively
2.1 ~ 3.1wt% and 1.7 ~ 2.7wt%.
3. a kind of flocculant according to claim 1, it is characterised in that: the dispersion is using ultrasonic agitation, mixing time
For 20 ~ 30min；The reaction condition is constant temperature water bath, and temperature is 45 ~ 50 DEG C, and the reaction time is 2 ~ 3h.
4. the processing method of Chrome Tanning Wastewater, including grid impurity elimination, add alkali to adjust, waste water sedimentation, acid adding is adjusted, it is characterised in that:
Waste water sedimentation is handled by flocculant, include in the flocculant amphiprotic high-molecule chelated flocculating agent PDMAMDTC and
Chitosan derivative adsorbent material.
5. the processing method of Chrome Tanning Wastewater according to claim 4, it is characterised in that: the grid goes to use mixedly mesh screen to be 30
~ 50 mesh, hydraulic detention time are 2 ~ 4h.
6. the processing method of Chrome Tanning Wastewater according to claim 4, it is characterised in that: the adjusting of described plus alkali is after impurity elimination
The alkaline solution that 3.8 ~ 4.3kg/t waste water is added in waste water carries out precipitation process, and the pH value of waste water is adjusted to 7 ~ 9.
7. the processing method of Chrome Tanning Wastewater according to claim 4, it is characterised in that: the waste water settlement treatment step
Are as follows: after adding flocculant into waste water, after reacting 20 ~ 30min under the mixing speed of 80 ~ 100r/min, 0.5 ~ 1h is stood, so
Supernatant is sent into conditioning tank afterwards, after lower sediment filtering, filtrate is sent into conditioning tank, and filter residue is sent into sludge drying pond.
8. the processing method of Chrome Tanning Wastewater according to claim 4, it is characterised in that: the dosage of the flocculant be 28 ~
35L/m2, wherein the weight ratio of amphiprotic high-molecule chelated flocculating agent PDMAMDTC and chitosan derivative adsorbent material is 2.1 ~ 2.6:
1.3。
9. the processing method of Chrome Tanning Wastewater according to claim 4, it is characterised in that: the amphiprotic high-molecule chelated flocculation
Agent PDMAMDTC is prepared by step in detail below: dimethyl diallyl ammonium chloride and acrylamide monomer is taken, by initiator
Cause and generates copolymer p (DMDAAC-AM)；It is then respectively adding formaldehyde and polyamines is linked, obtain aminated copolymer；Most
Afterwards under alkaline environment, reacts aminated copolymer and carbon disulfide and generate PDMAMDTC.
10. the processing method of Chrome Tanning Wastewater according to claim 9, it is characterised in that: the copolymer p (DMDAAC-
AM inherent viscosity) is 130 ~ 150mL/g, and cationic degree is 30.5 ~ 35.5%.
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Application publication date: 20190712 |