CN1385380A - Method for treating acrylonitrile and acrylic waste water - Google Patents

Abstract

The method for treating waste water produced by adopting dry and wet method to produce acrylonitrile and polyacrylonitrile fibre includes the following steps: adopting contact oxidation method of adding carbon black or powdered active carbon into the polymeric waste water to make biological pretreatment, for spinning waste water in waste water produced by using wet method to produce polyacrylonitrile fibre adopting coagulating flotation process to make physic-chemical pretreatment; mixing the pretreated waste water with other waste water and making then undergo the processes of biological oxidation and denitrogenation treatment by utilizing biological A/O method, then making the treated outlet water be up to discharge standard.

Description

Vinyl cyanide, Nitrilon waste water treatment process

The present invention relates to a kind of treatment process of wastewater from chemical industry, more specifically to the treatment process of industrial comprehensive wastewater in a kind of vinyl cyanide, the acrylic fiber production process.

Acrylonitrile polymerization system acrylic fibers method is divided into wet method and dry method two big classes.The wet production Nitrilon waste water generally is divided into vinyl cyanide series waste water and Nitrilon waste water two parts.Vinyl cyanide series waste water C mainly is meant production drainings such as vinyl cyanide, sulphur ammonium, sodium cyanide.Nitrilon waste water mainly is meant polymerization waste water A (comprising waste water such as MONOMER RECOVERY, polymkeric substance dehydration washing) and solvent recuperation waste water D and a small amount of other waste water E.In producing, wet spinning acrylic fiber also has filature wastewater B in addition.The feature of polymerization waste water A is that CODcr concentration is higher, contains a large amount of CN ^-, AN, acetonitrile, B-sodium allylsulfonate, oligopolymer, EDTA, NH ₃-N, SO ₄ ^2-Deng; The feature of solvent recuperation waste water D is that CODcr concentration is higher relatively, contains a large amount of spinning solvent such as NaSCN, dimethyl formamide (DMF) etc.The feature of filature wastewater B is that CODcr concentration is relatively low, contains NaSCN and pollutents such as polymkeric substance, tensio-active agent.

At present both at home and abroad for the treatment process of vinyl cyanide, acrylic fiber production wastewater mainly based on biochemical treatment, each strand waste water is mixed, adopt tower biological filter method, pure-oxygen aeration method, A/O biomembrance process, active sludge table to expose to the sun-biomembrance process contact oxidation method etc.Some also adds SAT-11, SAT-13, TD1, TD2 etc. and removes CN in the aeration tank ^-, SCN ^-Special bacterial classification.But because recalcitrant substance is more in the waste water, the water outlet CODcr after the processing can not reach discharging standards.CN 97107031 discloses a kind of improved wet spinning acrylic fibers production wastewater treatment method.This method is divided into three parts with waste water, adopt mixed condensed gas flotation process pre-treatment polymerization waste water A earlier, after adopting biological contact oxidation process pre-treatment filature wastewater B and solvent recuperation waste water D, again above-mentioned pretreated waste water is mixed with vinyl cyanide series waste water C and other waste water E and carry out the A/O biochemical treatment, remove CODcr, NaSCN, NH in the waste water thereby reach ₃The purpose of pollutents such as-N.The problem that this method exists is:

1, mixed condensed gas flotation process is handled the oligopolymer that the polymerization waste water A can only be removed less than 50%, and it is not obvious to the CODcr in the waste water, AN, acetonitrile and various removal effect to biological nuisance and hard-degraded substance, cause the microorganism active of follow-up A/O section low, zoogloea is loose, a large amount of spores are arranged, treatment effect is relatively poor, and the CODcr clearance is generally 60～80%;

2, add poly-iron in mixed condensed gas flotation process is handled and carry out coagulating treatment, the flocs unit proportion of formation is bigger, is difficult for air supporting and removes, and the residue of staying in the device is more, influences follow-up biochemical treatment;

3, spinning and solvent recuperation waste water D adopt biological contact oxidation process that NaSCN is carried out pre-treatment separately, have increased the complexity of equipment input, working cost and operation, and have not improved the total clearance of CODcr in the waste water;

4, the A/O section adopts the suspension activated sludge process to be unfavorable for reservation, the enrichment of advantage degradation bacteria in the biochemistry pool, and the molysite that adds then causes the increase of working cost for this reason;

5, this method only is applicable to NaSCN the processing of the wet spinning acrylic fibers factory effluent that is solvent, because it is solvent that the dry-spinning acrylic fiber production process adopts DMF, do not contain NaSCN, and contain multiple auxiliary component such as EDTA in the waste water, therefore be unsuitable for adopting this method of wastewater treatment.

The purpose of this invention is to provide a kind of problem that can overcome above-mentioned existence, wet method, dry-spinning acrylic fiber production process all are suitable for, and treatment effect is better than the method for wastewater treatment of CN97107031.

The objective of the invention is to be achieved through the following technical solutions.

In vinyl cyanide of the present invention, the Nitrilon waste water treatment process, described waste water comprises the polymerization waste water A in the acrylic fiber production process device, vinyl cyanide series waste water C, and solvent recuperation waste water D, other waste water E, described wastewater treatment step comprises:

The independent advanced person of the waste water A oxygen biochemical treatment of acting charitably, purpose is with the oligopolymer in the waste water, CN ^-, AN, acetonitrile and various general biochemical treatment difficult degradation and the material decomposition of the toxic effect of biology removed, and remove the CODcr more than 90% in the waste water simultaneously.

To carry out A/O series connection biochemical treatment through above-mentioned pretreated waste water A with not through pretreated waste water C, D, E mixing again.The purpose of A/O series connection biochemical treatment is that the CODcr that further removes in the waste water removes NH simultaneously ₃Discharge behind-the N, draining water quality can reach GB8978-1996 comprehensive wastewater first discharge standard.

In addition, above-mentioned method of wastewater treatment also comprises the processing of the filature wastewater B during wet spinning acrylic fiber produced.Can carry out coagulation-air supporting method pre-treatment separately earlier to waste water B, purpose is recalcitrant substance and the 60% above SCN that removes in the waste water ^-And 70～80% CODcr, and then, carry out A/O series connection biochemical treatment with the pretreated waste water A of above-mentioned process and not through pretreated waste water C, D, E mixing.

Be described in further detail the concrete steps of vinyl cyanide of the present invention, Nitrilon waste water treatment process below in conjunction with accompanying drawing.

Accompanying drawing 1 is an acrylic fiber production wastewater processing technological flow synoptic diagram

As shown in the figure, the kind of waste water comprises the polymerization waste water A in the acrylic fiber production process device in the method for wastewater treatment of the present invention, vinyl cyanide series waste water C, solvent recuperation waste water D, and other easy biochemical treatment waste water E of plant area.Described wastewater treatment step is: the independent advanced person of the waste water A oxygen biochemical treatment of acting charitably; To carry out A/O series connection biochemical treatment behind the solid matters such as floating matter in grid sedimentation basin removal waste water and sand through above-mentioned pretreated waste water A with not through pretreated waste water C, D, E mixing again; Above-mentioned method of wastewater treatment can also comprise the processing to the filature wastewater B in the wet spinning acrylic fiber production, waste water B can carry out coagulation-air supporting method pre-treatment separately earlier, and then, carry out A/O series connection biochemical treatment with the pretreated waste water A of above-mentioned process and not through pretreated waste water C, D, E mixing.

The method of above-mentioned A/O biochemical treatment is: the A section adopts the anaerobic device of up-flow anaerobic sludge blanket; The O section adopts the aerobic bio-contact oxidation pond of containing soft fiber shape immobilization carrier.The A/O biochemical treatment system is meant waste water after overregulating homogenizing process, and in CODcr: P=100: 0.4～0.8 ratio adds microcosmic salt, by in every liter of waste water with CaCO ₃The amount of the basicity of meter 250～300mg adds NaHCO ₃, Na ₂CO ₃Or NaOH, waste water enters the A/O biochemical treatment system processing that contains soft fiber shape immobilization carrier then; Its control condition can for:

The anoxic residence time: 2～10h,

The aerobic residence time: 12～24h,

Volumetric loading: 0.2～2.0Kg CODcr/m ³D,

15～36 ℃ of water temperatures,

pH?????????????????6～9，

A/O reaction tank dissolved oxygen DO A section＜0.1mg/L,

O section＞2.0mg/L,

Sludge concentration 2～10g/L,

Return sludge ratio 1: 1～1: 5.

The A/O biochemical treatment system comprises waste water adjusting homogenizing process.In CODcr: P=100: 0.4～0.8 ratio add microcosmic salt and by the basicity of 250～300mg in every liter of waste water (with CaCO ₃Meter) amount adds NaHCO ₃, Na ₂CO ₃Or NaOH, waste water is introduced into the waste water that A section and the part of being returned by O section second pond finish nitration reaction and carries out denitrification reaction then, and the waste water after the denitrogenation enters the O section again to carry out aerobic biochemical and handles, and removes CODcr, the BOD5 in the waste water and makes NH ₃-N is oxidized to nitric nitrogen, enters second pond then, and supernatant liquor partial discharge, another part are back to the A section and carry out denitrogenation.The condition of controlling in the A/O biochemical treatment is:

The anoxic residence time: 2～10h;

The aerobic residence time: 12～24h;

Volumetric loading: 0.2～1.0Kg CODcr/m ³D

0.025～0.5Kg?NH ₃-N/m ³·d

Water temperature: 15～36 ℃

pH：??????????????6～9

Reaction tank dissolved oxygen DO:A section＜0.1mg/L

O section＞1.5mg/L

Active mud content: 2～30g/L

Reflux ratio: 1: 1～5: 1

The aerobic biochemical of above-mentioned waste water A is handled can adopt the embrane method charcoal method of wastewater treatment that contains soft fiber shape immobilization carrier.The steps include: waste water A after settling tank is removed suspended substance, adjusting pH=3～9, preferred pH=6～8; In waste water COD cr: P=100: 0.4～0.8 ratio adds microcosmic salt; Enter the charcoal contact-oxidation pool that has added carbon black and/or Powdered Activated Carbon then and carry out the aerobic biochemical pre-treatment.Make in sealed furnace by several atomic little powder particles of forming to the dozens of carbon atom by cracking by Sweet natural gas, coal gas or stock oil for carbon black, and its particle size range is 9～130nm, and majority is 40～50nm.Powdered Activated Carbon is meant the finely powdered gac of being made by timber, shell, coal class, and granularity is 0.12～2.75mm.These powder particle parts combine with microbial cells, and another part is suspended in the water then freely.Carbon black or Powdered Activated Carbon can adsorb pollutants in waste water, increase its residence time in treatment system, shorten the space length of pollutent and microorganism, make the biochemical degradation reaction be easier to carry out.Carbon black granules more can permeate through cell membranes enter thalline inside, and influence also changes the inherited character of bacterium, and mutagenesis or induce the enzyme system of efficient decomposing organic matter makes originally non-biodegradable organism be degraded, and makes waste water obtain deep purifying.Handle through aeration biochemical, make CODcr, AN, NaSCN and oligopolymer etc. in the polymerization waste water A be converted into NH ₃-N, SO ₄ ^2-, CO ₂Deng inorganics and remove, water outlet relies on the gravity natural subsidence in second pond, and isolated charcoal flco returns contact-oxidation pool.

Carbon black or Powdered Activated Carbon can use separately also can mix use.The adding mode can join in the biochemical treatment apparatus with any suitable manner, as: add by pipeline continuously or off and on or solid directly adds with the form of aqueous slurry.Total dosage of carbon black can be 5～50% of an active mud content, and is preferred 10～15%, and carbon black also can be by 0.02～20g/L (reactor volume), and preferred 0.04～10g/L adds; Total dosage of Powdered Activated Carbon can be 3～5 times of carbon black, also can be by 0.1～50g/L, and preferred 0.2～20g/L adds.Along with the generation of newborn active sludge, need often add carbon black or Powdered Activated Carbon, the gap periods that carbon black or Powdered Activated Carbon add is 1～150 day, preferred 30～60 days.The control condition of above-mentioned aerobic biochemical treating processes can for:

Biochemical treatment load≤5Kg CODcr/m ³D is preferably 0.5～3Kg CODcr/m ³D;

Water inlet CODcr concentration 800～2000 mg/L

5～40 ℃ of water temperatures are preferably 15～35 ℃;

PH 5～10, are preferably 6～9;

Dissolved oxygen concentration 2～5mg/L is preferably 4～10g/L.

The treating processes of above-mentioned waste water B mixed condensed gas flotation process is: filature wastewater B is through the homogeneous equalizing tank, regulate pH=5～8, be preferably 6～7, water temperature＜40 ℃, adding earlier coagulating agent makes in the water dissolved pollutent separate out, add flocculation agent then and fine suspension assembled be big suspended substance, after air-floating apparatus from waste water, remove.Above-mentioned coagulating agent can be polymerize aluminum chloride or bodied ferric sulfate, and the dosage of poly-aluminium is 20～120mg/L waste water, is preferably 60～100mg/L; PH is 5.5～7; The dosage of poly-iron can be 50～150mg/L waste water, and described flocculation agent is meant anionic polyacrylamide, and dosage is 1.5～10mg/L waste water.

Obviously, for dry-spinning acrylic fiber production process method, its waste water is mainly the waste water that produces after polymerization waste water A, the solvent recuperation and reaches other waste water such as a small amount of cleaning, fluid-tight.This waste water only need adopt the charcoal catalytic oxidation pre-treatment polymerization waste water A in the aforesaid method flow process to mix with other waste water E then to carry out A/O bio-oxidation and denitrogenation processing, need not the flocculation-flotation pre-treatment.

The inventive method characteristics and advantage:

1, the inventive method to the treatment effect of vinyl cyanide, acrylic fiber production wastewater is: CODcr, BOD ₅, NaSCN, AN, NH ₃The clearance of principal pollutant such as-N is respectively 90～95%, 95～98%, 98～100%, 98～100%, 85～90%.This method can make the drainage index after any vinyl cyanide, acrylic fiber production wastewater are handled all reach national GB 8978-1996 comprehensive wastewater primary standard.

2, the present invention is directed to the different characteristics of each strand waste water in vinyl cyanide, the acrylic fibers industry waste water, adopt different treatment processs to handle respectively.Have simple and practical flow, stable, the high characteristics of removal efficient of treatment effect with present method flow processing acrylic fibers industry waste water.Acrylic fiber production wastewater for wet method, dry method all is suitable for, and difference is not have the flocculation-flotation pre-treatment step that spinning waste water B saves filature wastewater B because of dry method.

3, the present invention adopts carbon black and Powdered Activated Carbon to bring out can not to be degraded usually in the microbiological deterioration waste water or the organic pollutant of difficult degradation first, and utilize they not only adsorbed in the waste water organism but also can be attached to the characteristics on the microbe, under the synergy of carbon black and Powdered Activated Carbon and microbial cells, improve the efficient of bio-purifying wastewater, and induce or mutagenesis produces special biological bacterial strain or biological enzyme system.CODcr clearance in the waste water significantly improves.Particularly the acrylic fiber polymerization waste water A is after the charcoal pre-treatment, because some routine biochemistry method difficult degradations are degraded to CO with the polymkeric substance that can not degrade and some to the deleterious material of biology ₂, NH ₃-N avoids follow-up biochemical treatment is had a negative impact.

4, the present invention is first with acrylic spinning waste water B and solvent recuperation waste water D separate treatment.Acrylic spinning waste water B carries out the coagulation air-float pre-treatment separately, removes most of difficult biochemical substances, has saved the catalytic oxidation pre-treatment step.The flocculation-flotation pre-treatment is compared with the bio-contact oxidation pre-treatment, and flocculation-air supporting pre-treatment makes the BOD of waste water ₅/ CODcr brings up to 0.4～0.6 by original 0.17～0.22, significantly improves the biodegradability of waste water, has improved follow-up A/O biochemical treatment effect.And the bio-contact oxidation pre-treatment not only can not improve the biodegradability of waste water, makes BOD on the contrary ₅/ CODcr reduces to 0.15～0.2 by 0.17～0.22, has increased the difficulty of follow-up A/O biochemical treatment, has reduced treatment effect.Therefore solvent recuperation waste water D directly carries out the A/O biochemical treatment owing to have biodegradable preferably, can reduce equipment volume, dosing and the working cost of coagulation air-float operating unit like this, and the overall process effect of waste water is had no effect.

5, acrylic spinning waste water B is after the coagulation air-float pre-treatment, and CODcr removes 70～80%, and NaSCN removes more than 50%.The CODcr of waste water can drop to 20～50mg/L after further biochemical treatment again, and the total clearance of CODcr is 90～95%.And the bio-contact oxidation pre-treatment connects the total clearance of the CODcr of A/O biochemical treatment only is 70～80%.In addition, the coagulation air-float pretreatment process has the treatment time, and few (the bio-contact oxidation time is 16～20h, and flocculation-flotation only needs 1.5h), save floor space (floor space of flocculation-flotation device only be bio-contact oxidation plant area area 1/5～1/4), working cost advantages such as low (flocculation-flotation methods be generally bio-contact oxidation about 3/4).

6, the O section in pre-treatment of acrylic fiber polymerization waste water A charcoal and the follow-up A/O biochemical system has all adopted the embrane method mode, and the A section adopts up-flow anaerobic sludge blanket (UASB) method, can make the special efficacy degradation bacteria be grown on the carrier regularly in a large number, and under a stable envrionment conditions, keep higher concentration, thereby make treatment system have higher degradation capability and shock resistance, and bookkeeping is convenient.

Further introduce and illustrate technical scheme of the present invention and technique effect below in conjunction with embodiment.Protection scope of the present invention is as the criterion with the content of claims, is not subjected to the restriction of following embodiment.The carbon black trade mark that uses among the following embodiment is N339, and Powdered Activated Carbon is that domestic certain gac factory tails over charcoal.

Embodiment 1

Certain wet spinning acrylic fiber factory discharging water quantity and quality such as table 1:

Table 1

		Vinyl cyanide series waste water C	Nitrilon waste water
						The polymerization waste water A	Filature wastewater B	Solvent recuperation waste water D
			Water	Normal (m 3/h)	????84.5				?104	????160	????50
Amount	Maximum (m 3/h)	????111				?230	????190	????80
			???????pH		????6～9				?3.5～7	????4～7.5	????4～7
??CODcr(mg/L)		????863～1400				?859～1820	????350～477	????572
			??BOD 5(mg/L)		????362～520				?178～320	????82～110	????232
??NaSCN(mg/L)		????/				?10	????32	????298
			??AN(mg/L)		????8.5～30				?110
??CN -(mg/L)		????1～5				?5.5	????1.3	????0.8
			??NH 3-N(mg/L)		????15				?38	????3.5	????3.9
??(NH 4) 2SO 4(mg/L)		????312
			Oligopolymer (mg/L)						?145	????29

Handle the method flow that adopts accompanying drawing 1, the continous way operation.Steady running result through 2 months is as follows:

1, the pre-treatment of polymerization waste water A charcoal

At first after settling tank sedimentation 4h removes part suspended particle and oligopolymer, enter the homogeneous pond, adjust pH to 6～8, entering the charcoal contact-oxidation pool again handles, carbon black and Powdered Activated Carbon add in the mode of progressively successively decreasing, and what of add-on are so that carbon black and Powdered Activated Carbon are not as the criterion substantially in the bio-chemical effluent.Water outlet after processing natural subsidence in second pond is separated active sludge with waste water, mud returns reaction tank, and supernatant liquor goes the A/O biochemical treatment.

The pretreated control condition of polymerization waste water A charcoal method is:

Hydraulic detention time: contact-oxidation pool 16h; Settling tank 2h;

Filler: soft cellulose filler;

Load: 2.4Kg CODcr/m3d; 800～2000mg CODcr/L

Water temperature: 20～35 ℃;

pH：??????????6～8；

Microcosmic salt dosage: CODcr: P=100: 0.5;

Carbon black dosage: 1-3 days 1g/L; 4-10 days 0.5g/L; 0.2g/L after the 16th day,

Account for 30% of active mud content until carbon black;

Powdered Activated Carbon dosage: 1-3 days 3g/L; 4-10 days 1.5g/L; 0.6g/L after the 11st day,

Account for 90% of active mud content until Powdered Activated Carbon;

Add the cycle: 60d;

Reaction tank DO:3～4mg/L;

The pre-treatment operation result sees Table 2.

Polymerization waste water A pre-treatment result during table 2 wet spinning acrylic fiber is produced

??CODcr(mg/L)			????AN(mg/L)			??NaSCN(mg/L)			Oligopolymer (mg/L)			????NH 3-N ????(mg/L)
														Water inlet	Water outlet	Clearance %	Water inlet	Water outlet	Clearance %	Water inlet	Water outlet	Clearance %	Water inlet	Water outlet	Clearance %	Water inlet	Water outlet
??859	??79	??90.8	??101	??1.2	??98.8	??9	????0.7	??92.2	??133	??9	??93.2	??42	?98
														??916	??92	??90.0	??103	??2.4	??97.7	??8	Do not detect	??100	??151	??13	??91.4	??38	?117
??1156	??100	??91.3	??108	??2.9	??97.3	??9	Do not detect	??100	??146	??11	??92.5	??41	?191
														??1426	??113	??92.1	??109	??1.6	??98.5	??10	????0.1	??99.0	??145	??10	??93.1	??39	?202
??1614	??115	??92.9	??110	??1.2	??98.9	??10	????0.6	??94.0	??145	??13	??91	??38	?209
														??1901	??127	??93.3	??100	??2.7	??97.3	??9	Do not detect	??100	??148	??17	??88.5	??40	?104

By table 2 as seen, polymerization waste water A CODcr clearance after the charcoal pre-treatment is 90.0～93.9%, and the NaSCN clearance is 92～100%, and the oligopolymer clearance is 88.5～93.2%, NH ₃-N has increased by 0.33～3.5 times.

2, filature wastewater B pre-treatment (method 1)

After the advanced homogeneous of filature wastewater B pond, equalizing tank transfer to 6～8 with pH, carry out coagulation air-float and handle, waste water is discharged into the second-stage treatment station after the air supporting, and scum silica frost goes processed.

Filature wastewater B coagulation air-float pretreatment condition:

Poly-aluminium dosage: 80mg/L;

Negatively charged ion PAM dosage: 2mg/L;

Coagulation pH:6～7;

Pre-treatment the results are shown in Table 3.

Table 3 filature wastewater B adopts poly-aluminium pre-treatment result

??????????CODcr(mg/L)			???????????NaSCN(mg/L)
						Water inlet	Water outlet	Clearance	Water inlet	Water outlet	Clearance
????350	????75	????78.6％	????41	????13	????68.3％
						????350	????79	????77.4％	????21	????10	????52.3％
????477	????91	????80.9％	????40	????13.5	????66.3％
						????477	????93	????80.5％	????29	????14	????51.7％
????477	????102	????78.6％	????32	????13.9	????56.6％

By the visible filature wastewater B of table 3 CODcr clearance after the flocculation pre-treatment is 77.4～80.9%, and the NaSCN clearance is 51.7～68.3%.

3, filature wastewater B pre-treatment (method 2)

The filature wastewater B identical with 2 adopts poly-iron to carry out the coagulation air-float pre-treatment as coagulating agent, and operation is with 2.

Filature wastewater B coagulation air-float pretreatment condition:

Poly-iron dosage: 80mg/L;

Negatively charged ion PAM dosage: 2mg/L;

Coagulation pH:6～7;

Pre-treatment the results are shown in Table 4.

Table 4 filature wastewater B adopts poly-iron pre-treatment result

???????????CODcr(mg/L)			??????????NaSCN(mg/L)
						Water inlet	Water outlet	Clearance	Water inlet	Water outlet	Clearance
????350	????77	????78.0％	????41	????15	????63.4％
						????350	????74	????78.9％	????21	????11	????47.6％
????477	????112	????76.5％	????40	????12	????70.0％
						????477	????91	????80.9％	????29	????12	????58.6％
????477	????93	????80.5％	????32	????15	????53.1％

By the visible filature wastewater B of table 4 CODcr clearance after poly-iron flocculation pre-treatment is 76.5～80.9%, and the NaSCN clearance is 47.6～70.0%, and treatment effect is close with poly-aluminium.In use can choose one as the case may be wantonly.

4, A/O biochemical treatment

, enter the A/O biochemical treatment system and handle by after producing the water displacement mixed through pretreated polymerization, filature wastewater B and solvent recuperation water, acrylonitrile process waste water, remove CODcr, NH in the waste water ₃Pollutents such as-N.The control condition of A/O biochemical treatment is:

Hydraulic detention time: A section 4h; O section 16h; Precipitation 2h;

Handle load: 0.6～0.8Kg CODcr/m ³D; 0.1～0.2Kg NH ₃-N/m ³D

Water temperature: 20～35 ℃

pH：????????????7～9

Dissolved oxygen (DO): A section＜0.1mg/L, O section 2～4mg/L

Sludge concentration: A section 15g/L, O section 5g/L

Reflux ratio: 4: 1

Total effluent quality such as table 5 after the A/O biochemical treatment:

The total effluent quality of table 5

Analysis project	?pH	????CODcr ????(mg/L)	??BOD 5??(mg/L)	????CN -???(mg/L)	??SCN -??(mg/L)	???NH 3-N ???(mg/L)
							Stable back the 5th day	8.18	????78	???28.5	????0.012	????2.1	????15.1
Stable back the 10th day	7.19	????117			????1.9	????14.4
							Stable back the 20th day	6.88	????54		????0.009		????12.9
Stable back the 35th day	6.01	????39	???29.2		????2.4	????10.6
							Stable back the 50th day	6.65	????63		????0.011	????1.6	????13.2

Mean value	??6.98	??70	????28.9	??0.011	??2.0	??13.2
							Discharge index	??6～9	??≤100	????≤30	??≤0.5	??≤30	??≤15
The individual event qualification rate	??100％	??100％	????100％	??100％	??100％	??100％

Test shows that every index of this treatment process water outlet all reaches national GB8978-1996 comprehensive wastewater first discharge standard.

Embodiment 2

The waste water water quantity and quality such as the table 6 of certain dry-spinning acrylic fiber production process factory discharging:

Table 6

		Vinyl cyanide series waste water C	The polymerization waste water A
				The water yield	Normal (m 3/h)	????80.4	????166
Maximum (m 3/h)	????121	????180
			????pH		????6～9	????3.5～6.5
CODcr(mg/L)		????822～1308					????959～1501
			BOD 5(mg/L)		????358～402	????150～271
AN(mg/L)		????8.4～31					????104
			CN-(mg/L)		????1.2～5.2	????5.5
NH 3-N(mg/L)		????15					????38～42
			(NH 4) 2SO 4(mg/L)		????311	????498
DMF(mg/L)							????101～122
			Oligopolymer (mg/L)			????143～175

Treatment process adopts the method flow (not comprising filature wastewater B) of accompanying drawing 1.Working method is a continous way.Treatment condition and result are as follows: the pre-treatment of 1, polymerization waste water A charcoal

At first after settling tank sedimentation 4h removes part suspended particle and oligopolymer, enter the homogeneous pond, adjust pH to 6～8, entering the charcoal contact-oxidation pool again handles, carbon black and Powdered Activated Carbon add in the mode of progressively successively decreasing, and what of add-on are so that carbon black and Powdered Activated Carbon are not as the criterion substantially in the bio-chemical effluent.Water outlet after processing natural subsidence in second pond is separated active sludge with waste water, mud returns reaction tank, and supernatant liquor goes the A/O biochemical treatment.

The pretreated control condition of polymerization waste water A charcoal method is:

Hydraulic detention time: contact-oxidation pool 16h; Settling tank 2h; Filler: soft cellulose filler; Load: 2.2Kg CODcr/m ³D; Water temperature: 20～35 ℃; PH:6～8; Microcosmic salt dosage: CODcr: P=100: 0.8; Carbon black dosage: 1-5 days 1g/L; 6-15 days 0.5g/L; 0.2g/L after the 16th day,

Account for 50% of active mud content until carbon black; Powdered Activated Carbon dosage: 1-3 days 4g/L; 4-10 days 2g/L; 1g/L after the 11st day,

Account for 150% of active mud content until Powdered Activated Carbon; Add the cycle: 30d; Reaction tank dissolved oxygen DO:3～5mg/L; Operation pre-treatment through 2 months the results are shown in Table 7.

Polymerization waste water A pre-treatment result during table 7 dry acrylic fiber is produced

??CODcr(mg/L)			?????AN(mg/L)			???????????DMF(mg/L)			Oligopolymer (mg/L)			??????NH 3-N ??????(mg/L)
														Water inlet	Water outlet	Clearance %	Water inlet	Water outlet	Clearance %	Water inlet	Water outlet	Clearance %	Water inlet	Water outlet	Clearance %	Water inlet	Water outlet
?959	??102	?89.4	??99	?1.4	??98.6	101	??3.1	?96.9	?143	?17	??88.1	?40	?108
														?1140	??93	?91.8	??102	?2.1	??97.9	115	??4.9	?95.7	?162	?14	??91.4	?39	?172
?1140	??100	?91.2	??102	?2.3	??97.7	119	??5.1	?95.7	?164	?13	??92.1	?41	?181
														?1501	??116	?92.3	??119	?1.8	??98.5	122	??6.2	?94.9	?171	?10	??94.2	?39	?201
?1213	??109	?91.0	??110	?1.3	??98.8	111	??5.3	?95.2	?169	?11	??93.5	?38	?199
														?1206	??107	?91.1	??108	?2.1	??98.1	108	??4.7	?95.6	?175	?15	??91.4	?42	?163

By table 7 as seen, the CODcr clearance in charcoal pre-treatment post polymerization waste water A is 89.4～92.3%, and the DMF clearance is 94.9～96.9%, and the oligopolymer clearance is 88.1～94.2%, and NH3-N has increased by 0.7～3.24 times.

2, A/O biochemical treatment

, enter the A/O biochemical treatment system and handle by after producing the water displacement mixed through pretreated Nitrilon waste water and acrylonitrile process waste water and other waste water E, remove CODcr, NH in the waste water ₃Pollutents such as-N.

The control condition of A/O biochemical treatment is:

Hydraulic detention time: A section 4h; O section 16h; Precipitation 2h; Handle load: 0.5～0.8Kg CODcr/m ³D

0.1～0.2Kg NH ₃-N/m ³The d water temperature: 15～35 ℃ of pH:7～9 dissolved oxygens (DO) A section＜0.1mg/L, O section＞4: 1 total effluent quality such as tables 8 after the A/O biochemical treatment of 1.5mg/L sludge concentration 8～20g/L reflux ratio:

The total effluent quality of table 8

Analysis project	????pH	??CODcr ??(mg/L)	????BOD 5???(mg/L)	????CN- ??(mg/L)	??NH 3-N ??(mg/L)
						Stable back the 4th day	????7.73	????82		??0.008	??14.5
Stable back the 10th day	????7.28	????91	????16.3		??14.8
						Stable back the 16th day	????6.46	????121		??0.017	??12.9
Stable back the 22nd day	????6.17	????71	????21.2		??14.1
						Stable back the 28th day	????6.09	????96		??0.021	??13.7
Mean value	????6.75	????92.2	????18.8	??0.015	??14.2
						Discharge index	????6～9	???≤100	????≤30	??≤0.5	??≤15
The individual event qualification rate	????100％	???100％	????100％	??100％	??100％

Test shows that every index of this treatment process water outlet all reaches national GB8978-1996 comprehensive wastewater first discharge standard.

Claims (10)

1. a vinyl cyanide, Nitrilon waste water treatment process, described waste water comprises the polymerization waste water A in the acrylic fiber production process device, vinyl cyanide series waste water C, solvent recuperation waste water D, other waste water E, described wastewater treatment step comprises:

The independent advanced person of the waste water A oxygen biochemical treatment of acting charitably;

To carry out A/O series connection biochemical treatment through above-mentioned pretreated waste water A with not through pretreated waste water C, D, E mixing again.

2. method of wastewater treatment according to claim 1, it is characterized in that: described waste water also comprises the filature wastewater B in the wet spinning acrylic fiber production, after waste water B carried out coagulation-air supporting method pre-treatment separately earlier, with the pretreated waste water A of above-mentioned process and not through pretreated waste water C, D, E mixing, carry out A/O series connection biochemical treatment again.

3. method of wastewater treatment according to claim 1 and 2 is characterized in that described A/O biochemical treatment is: the A section adopts the anaerobic device of up-flow anaerobic sludge blanket; The O section adopts the aerobic bio-contact oxidation pond of containing soft fiber shape immobilization carrier.

4. according to the described method of wastewater treatment of claim 1, it is characterized in that described aerobic biochemical is treated to the embrane method charcoal method of wastewater treatment that contains soft fiber shape immobilization carrier, the steps include: waste water A after settling tank is removed suspended substance, adjusting pH=3～9; In waste water COD cr: P=100: 0.4～0.8 ratio adds microcosmic salt; Enter the charcoal contact-oxidation pool that has added carbon black and/or Powdered Activated Carbon then and carry out the aerobic biochemical processing.

5. method of wastewater treatment according to claim 4 is characterized in that: described waste water A is regulated pH=6～8 after settling tank is removed suspended substance; Total dosage of described carbon black is 5～50% of an active mud content, and total dosage of Powdered Activated Carbon is 3～5 times of carbon black; Or carbon black adds by 0.02～20g/L, and Powdered Activated Carbon is by 0.1～50g/L; The gap periods that carbon black or Powdered Activated Carbon add is 1～150 day.

6. method of wastewater treatment according to claim 4 is characterized in that: total dosage of described carbon black is 10～15% of an active mud content; Carbon black adds by 0.04～10g/L; Powdered Activated Carbon adds by 0.2～20g/L; The adding gap periods of carbon black or Powdered Activated Carbon is 30～60 days.

7. according to the described method of wastewater treatment of claim 2, the mixed condensed gas flotation process treating processes that it is characterized in that waste water B is: filature wastewater B is through the homogeneous equalizing tank, regulate pH=5～8, water temperature＜40 ℃, adding earlier coagulating agent makes in the water dissolved pollutent separate out, add flocculation agent then and fine suspension assembled be big suspended substance, after air-floating apparatus from waste water, remove.

8. method of wastewater treatment according to claim 7 is characterized in that described coagulating agent is polymerize aluminum chloride or bodied ferric sulfate, and the dosage of poly-aluminium is 20～120mg/L waste water, and the dosage of poly-iron is 50～150mg/L waste water; Described flocculation agent is meant anionic polyacrylamide, and dosage is 1.5～10mg/L waste water.

9. according to claim 1,3,4,5, one of 6 described method of wastewater treatment, it is characterized in that the control condition of described aerobic biochemical treating processes is:

Biochemical treatment load≤5Kg CODcr/m ³D;

Water inlet CODcr concentration 800～2000mg/L;

5～40 ℃ of water temperatures;

pH?????????????????????5～10；

Dissolved oxygen concentration 2～5mg/L.

10. method of wastewater treatment according to claim 3 is characterized in that the A/O biochemical treatment system is meant waste water after overregulating homogenizing process, and in CODcr: P=100: 0.4～0.8 ratio adds microcosmic salt, by in every liter of waste water with CaCO ₃The amount of the basicity of meter 250～300mg adds NaHCO ₃, Na ₂CO ₃Or NaOH, waste water enters the A/O biochemical treatment system processing that contains soft fiber shape immobilization carrier then; Its control condition is:

The anoxic residence time: 2～10h,

The aerobic residence time: 12～24h,

Volumetric loading: 0.2～2.0Kg CODcr/m ³D,

15～36 ℃ of water temperatures,

pH?????????????????????6～9，

A/O reaction tank dissolved oxygen DO A section＜0.1mg/L,

O section＞2.0mg/L,

Sludge concentration 2～10g/L,

Return sludge ratio 1: 1～1: 5.