CN101979416B

CN101979416B - Preparation of novel acrylamide high-polymer chelating agent and application thereof to stabilization treatment of hazardous waste

Info

Publication number: CN101979416B
Application number: CN2010102766962A
Authority: CN
Inventors: 孙学芹
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2010-09-09
Filing date: 2010-09-09
Publication date: 2012-08-29
Anticipated expiration: 2030-09-09
Also published as: CN101979416A

Abstract

The invention relates to preparation and application of a novel high-polymer chelating agent which contains a heavy metal hazardous waste and is applied to stabilization treatment. The high-polymer chelating agent of the invention is an addition compound product of polyacrylamide and carbon disulfide, achieves good treatment effect on a solid or liquid waste and reaches the national waste landfill control standard. A synthesis process of the invention is simple, has low cost, can efficiently treat heavy metals in industrial or domestic garbage incineration wastes and is applied to a certain urban incineration fly ash curing enterprise.

Description

The preparation of novel propylene acid amides high-molecular chelating agent and the application in the danger wastes stabilization treatment

Technical field

The invention belongs to a kind of preparation and application that stabilization treatment contains the novel high polymer sequestrant of heavy metal danger wastes that be used for.

Background technology

Along with the rapid propelling of Chinese Urbanization's process, urban population increases rapidly, and the consumption of resident level also improves constantly, and the processing of domestic waste is paid more and more attention.Along with the continuous popularization of consumer waste incineration processing mode, large-scale garbage burning factory has all successively been built on ground such as Beijing, Shanghai, Shenzhen, Chongqing and Changzhou at present.The processing of flying ash becomes a problem that must solve.Through the flying ash after the pretreatment, after reaching " household refuse landfill sites pollution control criterion " marching into the arena in (TB16889-2008) and requiring, the household refuse landfill sites landfill of being allowed for access.

The disposal options of flying ash is a lot, and that generally adopts at present has 4 kinds: cement solidification, sour solvent extraction, melting and solidification and chemical agent stabilization etc.Cement solidification equipment, operational requirement are simple; And the curing expense is relatively low; But it is big that back increase-volume amount is handled in cement solidification, and if contain in the flying ash when hindering the normal agglomerative composition of cement, problems such as cured body intensity is low, objectionable impurities leaching yield height take place in regular meeting; Thereby the acid solvent extraction can propose the part metals in the flying ash to make flying ash get into common landfill yard; But different flying ashs is because differences such as domestic refuse composition, burning conditions; The existence form of heavy metal and content have very big-difference in the flying ash; Therefore, even under same treatment condition, treatment effect has very big difference; Fusion technology mainly is that the flying ash and the tiny vitreous are mixed, after the mixing granulation moulding, and fusion for some time under 1000-1400 ℃ of high temperature; After treating the physics and chemical state change of flying ash; Cooling makes its curing, forms the vitrification body, by Vitrea compact crystal structure; Guarantee the stable of heavy metal, shortcoming is that the required energy and expense are very high; Chemical agent is stable to be to utilize chemical agent to make hazardous and noxious substances change the process of low-solubility, low migration and hypotoxicity material into through chemical reaction; Can be when realizing that refuse is innoxious; Reach the refuse perhaps not increase-volume that reduces, the material after the transformation can carry out sanitary landfill.

Chemical agent stabilization method technology by extensive concern, is used maximum metal chelators that is to use because running cost is low at present, like YD 30 (EDTA), diethylene triamine pentacetic acid (DTPA) (DTPA), terepthaloyl moietie-two-(the amino ether of 2-) tetraacethyl (EGTA).But domestic related patent U.S. Patent No. seldom; Wang Wei, Jiang Jianguo etc. constitute basic framework with polyamines or polymine; Under alkaline condition, reacted the application of synthetic metal chelator related patent U.S. Patent No. (CN200410090662.9) with dithiocarbonic anhydride; Tested the stabilization treatment of electroplating wastewater processing experiment and incineration of refuse flyash, the stabilization treatment of danger wastes is domestic does not also see related patent U.S. Patent No. and similar amide structure is used for as the sequestrant of skeleton.

Summary of the invention

The present invention provides a kind of novel high polymer sequestrant, is used for the stabilization treatment of danger wastes; The present invention provides and uses this novel high polymer sequestrant to carry out the flying ash curing process flow process (Fig. 1) of the stabilization treatment of danger wastes.Flying ash after the processing is tested through national authentication unit, and effect is obvious, has reached heavy metal refuse landfill state control standard, has been used for certain city flying ash and has solidified enterprise.

Novel high polymer sequestrant provided by the invention, staple are the adduct of a kind of polyacrylamide polymers (or multipolymer) and dithiocarbonic anhydride.With polyacrylamide polymers (or multipolymer) is skeleton, and surveyor's chain connects the dithiocarbonic anhydride molecule, structure and reaction formula such as Fig. 2.Its advantage: cost of material is cheap, and the preparation method is simple.

The present invention with SEPIGEL 305 as polymer backbone; Be because SEPIGEL 305 (PAM) is a kind of linear macromolecule polymkeric substance commonly used; Price low (SEPIGEL 305 (PAM) market value is far below polycaprolactam polyamine (PPA)), water-soluble strong, can carry out the number of chemical reaction; Have good flocculence, can be used as flocculation agent, sludge dehydrating agent etc.SEPIGEL 305 has been widely used in water treatment and wastewater treatment at present.SEPIGEL 305 and CS in the present invention ₂In conjunction with after formed PAM-S with strong sequestering action, the sulphur atom on the surveyor's chain is contents of many kinds of heavy metal ion such as the Hg in chelating solid or the solution, Cd, Cu, Pb, Mn, Ni, Zn, Cr effectively.

SEPIGEL 305 high-molecular chelating agent of the present invention (PAM-S) is with after flying ash mixes; Form intramolecularly, intermolecular firm metal-S key with heavy metal; With similar flying ash chemical stabilizer polycaprolactam polyamine chelators; The sulphur atom that plays sequestering action more is prone to and heavy metal chelating away from polymer chain, and polymkeric substance has also formed the molecular structure (Fig. 3) of crosslinked shape through chelating simultaneously.The different metal atom is owing to the different amts that forms covalent linkage with sulphur atom forms the inner complex of different structure, but finally forms the molecular structure of crosslinked shape.The molecular structure of this crosslinked shape has the molecular weight and complicated three-dimensional structure of super large, and solubleness is very poor, and has very high stability.

Embodiment

Embodiment 1

(1) preparation of high-molecular chelating agent:

The SEPIGEL 305 of buying on the market can be anionic polyacrylamide (APAM), cationic polyacrylamide (CPAM), non-ionic polyacrylamide (NPAM), zwitter-ion SEPIGEL 305 (ACPAM).Molecular weight is at 200-1000 ten thousand.

70g SEPIGEL 305,40g NaOH, 500mL water are added reaction kettle.Stirring mixes it, is heated to 80 ℃ and continues 1 hour.Be cooled to 40 ℃, drip dithiocarbonic anhydride 70g, dropwise continued and stirred 10 hours, get the brown clear solution.Be cooled to the secure satisfactory grades aqueous solution of sub-sequestrant of room temperature.

(2) utilize of the processing experiment of above-mentioned sequestrant to flying ash:

Domestic and foreign literature shows; What flying ash leached concentration over-standard mainly is plumbous; Certain city flying ash solidifies enterprise, and the content of arsenic is also higher in the flying ash, uses above-mentioned sequestrant to carry out the flying ash solidification treatment; Adopt TCLP method dissolution test, measured the concentration (seeing table 1) that flying ash after handling leaches plumbous and arsenic.

Leach plumbous concentration after the table 1 flying ash solidification treatment

Project	Test 1	Test 2	Test 3	Test 4	Leaching standard (mg/l)
						Flying ash (g)	100	100	100	100
Sequestrant (g)	0	0	1	2
						Cement (g)	0	20	20	0
Water (g)	30	30	29	28
						Plumbous (mg/l)	14.4	1.4	0.05 below	0.05 below	5
Arsenic (mg/l)	10.9	7.1	1.13	1.02	5

Annotate: the concentration that other heavy metal of stipulating among the GB5085.3-2007 leaches has also reached national refuse standard of landfill

Embodiment 2

(1) preparation of high-molecular chelating agent:

70g SEPIGEL 305,80g NaOH, 1L water are added reaction kettle.Stirring mixes it, is heated to 80 ℃ and continues 1 hour.Be cooled to 40 ℃, drip dithiocarbonic anhydride 140g, dropwise continued and stirred 10 hours, get the brown clear solution.Be cooled to the secure satisfactory grades aqueous solution of sub-sequestrant of room temperature.

The same employing implemented certain city flying ash curing enterprise flying ash in 1; Use above-mentioned sequestrant to carry out the flying ash solidification treatment; Adopt TCLP method dissolution test, measured the concentration (seeing table 2) that flying ash after handling leaches plumbous and arsenic, reached national refuse landfill control criterion.

Leach plumbous concentration after the table 2 flying ash solidification treatment

Project	Test 1	Test 2	Test 3	Test 4	Leaching standard (mg/l)
						Flying ash (g)	100	100	100	100
Sequestrant (g)	0	0	1	2
						Cement (g)	0	20	20	0
Water (g)	30	30	29	28
						Plumbous (mg/l)	14.4	1.4	0.05 below	0.05 below	5
Arsenic (mg/l)	10.9	7.1	1.73	1.32	5

Table 1, table 2 show, add cement in the flying ash and can reduce heavy metal and leach concentration, thereby use sequestrant less, but when the sequestrant dosage be 2% when above of flying ash amount, interpolation cement is little to the leaching concentration affects.

After adding cement, the ultimate compression strength of flying ash cured article increases, and cured article keeps its block-shape morphology after getting into landfill yard when high compressive strength helps compacting operation, weaken the erosion of acidic liq.

Handle flying ash with intercalating agent, can realize innoxious in, reach the refuse perhaps not increase-volume that reduces, thereby improve the overall efficiency and the economic rationality of Hazardous wastes treatment and disposal system.

Description of drawings: Fig. 1 is a flying ash curing process flow process.Fig. 2 is structure and reaction formula.Fig. 3 is a polymkeric substance chelating corsslinking molecular structure.

Claims

1. novel high polymer sequestrant that is used for the stabilization treatment of danger wastes is characterized in that staple is the adduct of SEPIGEL 305 and dithiocarbonic anhydride, the preparation method of this novel high polymer sequestrant:

(1) SEPIGEL 305, NaOH, water are added reaction kettle, stirring mixes it;

(2) mole number of NaOH be the SEPIGEL 305 mole number 0.8-2 doubly, every gram SEPIGEL 305 adds 7-14g water;

(3) be heated to 50-80 ℃ of lasting 1-5 hour;

(4) be cooled to 10-40 ℃, drip dithiocarbonic anhydride, dropwise continued and stirred 2-16 hour;

(5) the brown clear solution, be cooled to the secure satisfactory grades aqueous solution of sub-sequestrant of room temperature.

2. a kind of novel high polymer sequestrant that is used for the stabilization treatment of danger wastes as claimed in claim 1 is characterized by Molecular Weight for Polyacrylamide at 200-1000 ten thousand.

3. a kind of novel high polymer sequestrant that is used for the stabilization treatment of danger wastes as claimed in claim 2, it is characterized by SEPIGEL 305 can be anionic polyacrylamide (APAM), cationic polyacrylamide (CPAM), non-ionic polyacrylamide (NPAM), zwitter-ion SEPIGEL 305 (ACPAM).

4. a kind of novel high polymer sequestrant that is used for the stabilization treatment of danger wastes as claimed in claim 1 is characterized by described dithiocarbonic anhydride and adds proportional 0.8-2 times for acid amides in the polymkeric substance.

5. use novel high polymer sequestrant as claimed in claim 1 to handle the technology of danger wastes.