Advanced treatment process for pulping papermaking sewerage and device thereof
Technical field
The present invention relates to a kind of advanced treatment process and device of pulping papermaking sewerage.
Background technology
Pulping papermaking sewerage belongs to high chroma, high basicity, high organic pollutant, highly difficult trade effluent that bio-degradable is low, contains organism such as multiple alkane, hydrocarbon, phenol, acid, benzene, alcohol, aldehyde, ketone, ether, anthracene, quinone, sugar, amine, Mierocrystalline cellulose, hemicellulose and lignin and derivative thereof, polymkeric substance, halides in the sewage.Enterprises in pulp and paper industry has generally all been carried out secondary biochemical treatment to its sewage, but the chemical oxygen demand (COD) of its water outlet (being called for short CODcr) is generally more than 150mg/L, the extension rate of colourity is greater than 64 times, can't satisfy the requirement of new national standard " pulp and paper industry pollution discharge standard " GB3544-2008, so must after existing secondary biochemical treatment, carry out advanced treatment.
Difference between new standard (GB3544-2008) and the old standard (GB3544-2001) mainly is: new standard is to CODcr, BOD
5(five-day BOD), SS index requests such as (suspended substances) are stricter, and have increased colourity, TN, TP index.Because nitrogen phosphorus lacks in the pulping papermaking sewerage, BOD has dropped to very low degree (being generally less than 10mg/L) in secondary biochemical treatment, and SS is easy to remove by coagulation, depositing technology, so what the advanced treatment of pulping papermaking sewerage was main is exactly the problem that solves its nondegradable organic pollutant and colourity, and be a great problem that field of water treatment faces for the removal and the decolouring of water-soluble and the organic pollutant that is not easy to degrade.
At present, the advanced treatment process for pulping papermaking sewerage that occurs at new standard generally adopts physico-chemical process, such as the absorption method of gac/activated coke, strong oxidizer oxidation style, electrolytic process, photocatalytic method, UF+RO (ultrafiltration+reverse osmosis) embrane method, lignin by acid separation method etc.But all there is certain defective in the technology of these several routines: absorption method need add a large amount of sorbent materials, adsorbs saturated back and loses efficacy, and cost is high and produce a large amount of mud; Oxidation style (ozone, hydrogen peroxide, hypochlorous acid etc.) decolorizing effect is not obvious, the processing cost height; Electrolytic process, that effect is sent out in photochemical catalysis is better, but the power consumption height causes running cost to accept; Although UF+RO embrane method treatment effect is good, need very strict pretreatment system, laid down cost and working cost are all very expensive; Lignin by acid separation need add a large amount of acid to water quality, adjusts back pH value with alkali again after xylogen is separated out, the processing cost height, and Xiang Shuizhong has added a large amount of ions.Want to reduce processing cost and can reach good treatment effect, must change traditional processing mode.
Summary of the invention
The technical problem to be solved in the present invention provides that a kind of technology is simple, cost is relatively low and guarantees the advanced treatment process for pulping papermaking sewerage and the device thereof of water outlet qualified discharge.
A kind of advanced treatment process for pulping papermaking sewerage may further comprise the steps:
1. the pulping papermaking sewerage after secondary biochemical treatment is carried out physico-chemical pretreatment;
2. the water outlet after 1. step being handled is introduced in the aerobe pond and is carried out biochemical treatment;
3. the water outlet after 2. step being handled is introduced in the sterilization pool and is carried out sterilization and disinfection;
4. the water after 3. step being handled carries out the qualified discharge or the clean water basin that induce one, and sends into the reuse water pipe network after the water pump pressurization.
The physico-chemical pretreatment of step described in 1. may further comprise the steps:
In A, the preaeration tank that will the pulping papermaking sewerage after secondary biochemical treatment induces one, make sewage carry out limited aeration and thorough mixing therein, remove in the sewage and can produce the foamy tensio-active agent;
B, the steps A water outlet introduced to take off in the steady pond react, and Xiang Chizhong adds recombiner, improve the biodegradability of sewage;
C, coagulation basin and settling tank are introduced in step B water outlet, in coagulation basin, added coagulating agent and flocculation agent, impel sewage to carry out coagulating sedimentation, in settling tank, realize mud-water separation.
The process of reacting in taking off steady pond is carried out aeration and effluent recycling simultaneously, and reflux ratio is 100%~200%, and then accelerates speed of reaction.
The sludge part that settling tank is discharged is back to coagulation basin, and sludge back flow quantity is 30%~50%, to save the input amount of medicament.
The residue biological sludge of remaining chemical sludge in the settling tank and the generation of aerobic biological tank is entered mud homogeneous concentration basin, outward transport after dewatering; Simultaneously, the overflowing liquid of dehydration filtrate and mud homogeneous concentration basin is introduced in the coagulation basin and is handled.
The coagulating agent that adds in coagulation basin is a polymerize aluminum chloride, and its dosage is 200~300mg/L; The flocculation agent that adds is a polyacrylamide, and its dosage is 0.5~1.0mg/L.
In sterilization pool, add strong oxidizer to the sewage sterilization that carries out disinfection, make CODcr from 80~100mg/L be reduced to 60~80mg/L, colourity is reduced to 8~16 times from 16~32 times; The strong oxidizer that adopts is dioxide peroxide or ozone, and be 15min the duration of contact of dioxide peroxide, and be 5~10min the duration of contact of ozone.
A kind of device of implementing advanced treatment process for pulping papermaking sewerage describedly takes off steady pond and adopts BAF structure formation, and stopping composition is a sponge iron, and sponge iron density is 1.6~1.8t/m
3, diameter is 4~6mm, treatment sewage in taking off steady pond with effective duration of contact sponge iron be 90~120min.
Compared with prior art, the present invention has the following advantages:
1, technology of the present invention is simple, cost is relatively low and treat effluent can qualified discharge.Carry out advanced treatment for pulping papermaking sewerage in the prior art and all adopt physico-chemical process through secondary biochemical treatment, such as absorption method, strong oxidation style etc., need in water, add a large amount of medicaments according to common process, the saturated back regeneration of adsorbents adsorb difficulty, cause processing cost very high, and be easy to generate secondary pollution, and when adopting this technology to carry out advanced treatment, the method that adopts materialization processing and biochemical treatment to combine, handle by the aeration in the materialization operation, take off steady operation and make xylogen in the sewage, chain rupture takes place lignin derivatives polymer organic chlorides etc. and free radical replaces, destroy chromophoric group, improved the biodegradability of sewage simultaneously, (B/C is about 0.4~0.5), be convenient to follow-up biochemical treatment, therefore the present invention becomes the sewage that pulping papermaking sewerage is a routine, after connect the biological treatment of saving energy consumption most, so make processing cost relatively low, water through above-mentioned processing, every index can both reach the requirement among the GB3544-2008, and satisfy the water quality requirement of paper technology reuse water, thereby reach the purpose that sewage recycling utilizes.
2, it is few to add the medicament total amount in the technology of the present invention, and the cost-effective sludge quantity that makes simultaneously reduces.This technology only needs to add copper-ammonia activator in taking off steady pond, in the flocculation basin settling tank, add flocculation medicament and coagulated agent, removed after making macromolecular substance take off surely, simultaneously, the settling tank sludge part is back to mixing pit, further reduce the medicament usage quantity with the absorption property that utilizes mud, saved the cost of a whole set of technology and reduced the sludge quantity that in sewage treatment process, produces.
3, technology of the present invention is employed takes off steady medium and is easy to get and does not produce secondary pollution.The steady medium that takes off that takes off in this technology in the steady pond is a sponge iron, and it is to be raw material with ore or pelletizing, makes reductive agent with solid or gas, is being lower than below the melting temperature of iron-carbon alloy, smelts and obtains, and because of containing the sponge-type porosity in inside, is named as sponge iron.It is spherical that sponge iron mostly is, and porous and tap density are little, are suitable for doing filtrate, need not do any processing, and material is easy to get, and price is more cheap, in use can not produce secondary pollution.
Description of drawings
The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments:
Fig. 1 is the process flow sheet of advanced treatment process for pulping papermaking sewerage of the present invention.
Embodiment
A kind of advanced treatment process for pulping papermaking sewerage may further comprise the steps:
1. the pulping papermaking sewerage after secondary biochemical treatment is carried out physico-chemical pretreatment;
2. the water outlet after 1. step being handled is introduced in the aerobe pond and is carried out biochemical treatment;
3. the water outlet after 2. step being handled is introduced in the sterilization pool and is carried out sterilization and disinfection, in the present embodiment, in sterilization pool, add strong oxidizer to the sewage sterilization that carries out disinfection, make CODcr from 80~100mg/L be reduced to 60~80mg/L, colourity is reduced to 8~16 times from 16~32 times; The strong oxidizer that adopts is dioxide peroxide or ozone, and be 15min the duration of contact of dioxide peroxide, and be 5~10min the duration of contact of ozone.;
4. the water after 3. step being handled carries out the qualified discharge or the clean water basin that induce one, and sends into the reuse water pipe network after the water pump pressurization.
The physico-chemical pretreatment of step described in 1. may further comprise the steps:
In A, the preaeration tank that will the pulping papermaking sewerage after secondary biochemical treatment induces one, make sewage carry out limited aeration and thorough mixing therein, remove in the sewage and can produce the foamy tensio-active agent, tensio-active agent has lipid acid and saponified, nonionic surface active agent thereof, resinous acid, alkyl-sulphate, sulfide etc.;
B, the steps A water outlet introduced to take off in the steady pond react, and Xiang Chizhong adds recombiner, improve the biodegradability of sewage, the B/C of water outlet is about 0.4~0.5;
C, coagulation basin and settling tank are introduced in step B water outlet, in coagulation basin, add coagulating agent and flocculation agent, impel sewage to carry out coagulating sedimentation, in settling tank, realize mud-water separation, the coagulating agent that adds in coagulation basin is a polymerize aluminum chloride, and its dosage is 200~300mg/L; The flocculation agent that adds is a polyacrylamide, and its dosage is 0.5~1.0mg/L.
The process of reacting in taking off steady pond is carried out aeration and effluent recycling simultaneously, and reflux ratio is 100%~200%, and then accelerates speed of reaction.
The sludge part that settling tank is discharged is back to coagulation basin, and sludge back flow quantity is 30~50%.
At last, the residue biological sludge with remaining chemical sludge in the settling tank and the generation of aerobic biological tank enters mud homogeneous concentration basin, outward transport after dewatering; Simultaneously, the overflowing liquid of dehydration filtrate and mud homogeneous concentration basin is introduced in the coagulation basin and is handled.
A kind of device of implementing advanced treatment process for pulping papermaking sewerage, describedly take off steady pond and adopt BAF structure formation, usually BAF comprises pond body, back-purge system etc., be provided with filter plate at Chi Tizhong, filtrate is layered on the filter plate, and filter is installed on filter plate, and the filtrate of filling among the present invention is a sponge iron, the density of sponge iron is 1.6~1.8t/m
3, diameter is 4~6mm, treatment sewage in taking off steady pond with effective duration of contact sponge iron be 90~120min.
With reference to Fig. 1, technical process of the present invention is as follows: be incorporated in the preaeration tank through the pulping papermaking sewerage after the secondary biochemical treatment, in the pond, carry out limited aeration and thorough mixing, remove the generation foamy tensio-active agent in the sewage, as: lipid acid and saponified, nonionic surface active agent thereof, resinous acid, alkyl-sulphate, sulfide etc.; After reacting about 30~45 minutes, send into by water pump and to take off steady pond, take off steady pond and adopt BAF structure formation, the filtrate of filling is a sponge iron, add trace copper-ammonia activator simultaneously, feed a little air in its bottom, and refluxed in the water part, reflux ratio is 100%~200%, and then accelerates speed of reaction; Water after taking off steady processing enters coagulation basin, add coagulating agent and coagulate agent to impel the particulate cohesion with flocculation, enter settling tank then and carry out mud-water separation, part mud is back to mixing pit and adds dose with minimizing, and excess sludge is expelled to mud homogeneous concentration basin pond by mud discharging mouth; The water outlet of settling tank enters the aerobe pond and carries out biochemical treatment, the purpose of aerobic treatment is to remove owing to taking off the BOD that steady reaction produces, the form in aerobe pond can be SBR pond (sequencing batch active sludge) or BAF pond (BAF), if adopt the SBR pond, then the cycle of operation is 4h, if adopt the BAF pond, then be 30~50min duration of contact; Remaining active sludge drains into mud homogeneous concentration basin in the aerobe pond, and the water outlet in aerobe pond enters clean water basin behind contact sterilizing, delivers to the reuse water pipe network by booster pump chamber; Mud is transported outward after the sludge dewatering equipment dehydration and is disposed, and liquid enters coagulation basin and handles by row's mouthful discharge after the overflowing liquid of mud homogeneous concentration basin and the filter of sludge dewatering equipment after the mixing.
Through the water of above-mentioned processing, every index can both reach the requirement among the GB3544-2008, and satisfies the water quality requirement of paper technology reuse water, thereby reaches the purpose that sewage recycling utilizes.