CN103864260A - Method for processing viscose fiber production wastewater - Google Patents

Abstract

The invention relates to the technical field of industrial wastewater processing, and specifically relates to a method for processing viscose fiber production wastewater. A large amount of acidic and alkaline wastewater is generated during production of viscose fiber, and severe water pollution and loss and waste of a large amount of fiber source are caused by direct discharge of the wastewater. The method for processing viscose fiber production wastewater is a technology formed by adding a processing technology combining shallow-layer air floatation and iron chip filtering on the basis of a processing technology combining a physicochemical process and a biochemical process. The beneficial effects generated by execution of the technical scheme comprise that source is utilized, cellulose in production wastewater of viscose fiber is recovered, fixed investment is reduced, production cost is reduced, and the quality of processed water can steadily reach national first-level discharge standard.

Description

A kind for the treatment of process of wastewater from viscose fiber producing

Technical field

The present invention relates to technology for treating industrial waste water field, be specifically related to a kind of wastewater from viscose fiber producing treatment process.

Background technology

Along with developing rapidly of industry, kind and the quantity of waste water rapidly increase, and the pollution of water body, also increasingly extensively with serious, is threatened to the mankind's health and safety.Viscose fiber output accounts for 1/3 left and right of chemical fibre ultimate production, and China's viscose fiber is produced per year and reached hundreds of thousands of ton, is main chemical fibre kind.In the production process of viscose fiber, produce a large amount of acid, alkali waste water, it directly discharges and will cause serious water to pollute and the loss waste of fibre resources in a large number.

Wastewater from viscose fiber producing mainly comprises the acid and large class of alkaline waste water two, and wherein acid waste water is mainly derived from spinning workshop and acid station, comprises plasticizing-bath overflow water, washes spinning-drawing machine water, the sour filter wash water of standing, washes a water and post treatment acid wash water etc.; Alkaline waste water is mainly derived from the draining of alkali station, stoste workshop waste water glue groove and equipment for washing water, filter cloth washing water, the desulfurization wastewater with water outlet and aftertreatment while changing spinning nozzle etc.

At present, the acid waste water and the alkaline waste water that in domestic production process of viscose fiber, produce adopt conventional materialization+biochemical processing process.

Materialization processing: the acid waste water producing in production process of viscose fiber and alkaline waste water are through mixing neutralization, aeration stripping sulfide, adding milk of lime dezincification and precipitation clarification.Due to viscose fiber, to produce the acidity of composite waste very strong and be rich in zinc salt and sulfide, and difficulty of governance is larger.There is following point in this treatment process:

1, waste water still strong (pH=2～3) of acidity after mixing, now the prezenta in raw wastewater in large quantities by acid out out, and Mierocrystalline cellulose volume quality is little, be difficult to thorough removal with conventional coprecipitation mode, thereby affect effluent quality, cause COD to exceed standard and waste with the loss of resource;

2, this technique is mainly removed sulfide (as H by aeration stripping mode ₂s, CS ₂deng), but be subject to the impact of factors, and stripping efficiency is not very high, water outlet often there will be S _2-the phenomenon exceeding standard;

3, add milk of lime dezincify precipitation process in, due to the optimal ph scope narrower (pH=8～9) of its precipitin reaction, reaction conditions is restive, adds artificial dispensing, often there is Zn in water outlet ²⁺the phenomenon exceeding standard;

4, because the pH value of composite waste is lower, reach follow-up precipitin reaction condition and need add a large amount of lime slurries, this has increased working cost first, second the large quantities of lime slag producing has increased the load in post precipitation pond, thereby has also increased the mud handling capacity in whole governance process and disposed difficulty.

Biochemical treatment: add again active sludge secondary biochemical treatment technique on the basis of materialization processing.Wastewater from viscose fiber producing is after materialization is processed, and some principal pollutant are (as COD, SO ^2-4, Zn ²⁺with sulfide etc.) there is quite a few to be removed, then through follow-up active sludge secondary biochemical treatment, make BOD in waste water ₅, COD etc. is able to further removal, while normally operation, water outlet can reach national grade one discharge standard.But still there are the following problems:

1, owing to being only to have increased activated sludge biochemical treatment process on the basis of materialization processing one, therefore some problems in former materialization treating processes (as high in loss waste, the working cost of resource, mud amount is large) still exist;

2, because the automatic controlling level of materialization treating processes is above not high, operating performance is unstable, makes the water outlet after coagulation often occur SO ^2-4, Zn ²⁺the phenomenon exceeding standard, and conventionally work as SO ^2-4> 1000mg/L or Zn ²⁺when > 20mg/L, microbial growth can be subject to obvious inhibition, and this has affected the efficiency of follow-up biochemical treatment greatly;

3, because materialization treating processes is above not high to the removal efficiency of COD, while making a large amount of light fibre elements that in waste water, acid out goes out enter follow-up activated sludge biochemical to process, pollution load is larger, active sludge is of low quality, the residence time that need to be longer, (5.7～9.5 h), this make whole initial cost and running cost higher, floor space is also larger.

On February 23rd, 2005, State Intellectual Property Office disclosed a kind of cotton pulp black liquor water, wastewater from viscose fiber producing integrated conduct method (publication number: 1583608), cotton pulp black liquor water after fully contacting with boiler smoke, boiler Venturi-water dust scrubber is entered to dirt ashpit, after precipitation, enter in acidifying equalizing tank, and carry out acidifying to the two bath overflow waters that pass into pH≤2 that produce in production process of viscose fiber in pond, control pH value to 5.5-7.5, then in the waste water after acidifying, successively add polymerize aluminum chloride and polyacrylamide to carry out flocculation reaction, after flocculation reaction, enter secondary sedimentation basins precipitation, after solid-liquid separation, utilize activated sludge process to carry out aerobic treatment.This technical scheme has only been introduced a kind for the treatment of process to the acid solution producing in production process of viscose fiber, and the unrealized processing to alkaline waste water.

Summary of the invention

The present invention solves the some shortcomings that exist in above-mentioned wastewater from viscose fiber producing improvement method, and proposition increases the treatment process of a kind of wastewater from viscose fiber producing of " shallow air-floatation+iron dust filtration " treatment process on the basis of " materialization+biochemistry " treatment process of routine.Its technical scheme realizes by following processing step:

A treatment process for wastewater from viscose fiber producing, comprises existing materialization processing, biochemical treatment operation, also comprises shallow air-floatation processing and iron dust filtration treatment process.Its technical process is:

Stripping reaction process → shallow air-floatation operation → iron dust filtration operation → hybrid reaction operation → biologic treatment process.

After the acidity that viscose fiber in described stripping reaction process produces in producing and alkaline waste water are mixed to pH=2～3 by proportioning, enter stripping reaction tank, acid out goes out to be in a large number the prezenta of suspension, most of H ₂s, CS ₂also be able to stripping removal Deng composition.

Described shallow air-floatation operation: the Rotatable water inlet water inlet tube through stripping reaction process former water after treatment from air flotation pool center, by rotation water distributing pipe water distribution, the translational speed of water distributor is identical with water inlet flow velocity, and the pond of air-floating apparatus is deeply generally no more than 650 mm.Water inlet stops 3～5min, and the removal efficiency of suspended substance can reach more than 85%.

So just produced " zero velocity ", water inlet can be to pond water generates disturbance in this state, and the suspension of particle is all carried out with sedimentation under a relative static state.According to " zero-speed theory " and " shallow pool theory ", make the water inlet residence time of this device short, surface load is high, and the removal efficiency of suspended substance can reach more than 85%.A large amount of Mierocrystalline celluloses are able to remove comparatively thoroughly and reclaim, and this had both reduced the pollution load of subsequent disposal, and the resource that has also realized prezenta reclaims.

Described iron dust filtration operation: air flotation pool water outlet has produced redox and electric attached collection effect through iron dust filtration, having there is chain rupture dezincify reaction in the principal pollutant in waste water, is beneficial to subsequent disposal to Zn ²⁺thorough precipitation remove, pH value and the biodegradability of waste water is all improved (pH=5～6), greatly reduced throwing alkali number and the sludge yield of follow-up neutralization precipitation, is also conducive to biochemical treatment process.Meanwhile, a large amount of Fe that this process produces ²⁺both can double as flocculation agent, making in post precipitation process needn't additional flocculating agents, can make again S residual in waste water ^2-mode with FeS precipitation is able to thorough removal.

Described hybrid reaction operation: the water outlet of iron dust filtration tower enters bent neck groove and calcium carbide emulsion or the abundant hybrid reaction of milk of lime, then enters preliminary sedimentation tank precipitation.By the input amount of pH value automatic controlling system calcium carbide emulsion or milk of lime, pH value in reaction is controlled at 8～8.5, now the Zn in waste water ²⁺by thoroughly precipitation removal, the most Fe in waste water ²⁺also be precipitated removal.

Through iron filings tower waste water after treatment, can precipitate completely through 0.5～1.0h; In addition, the minute quantity Fe containing in water outlet ²⁺, it is the important component part of bio-oxidation enzyme, simultaneously at Fe ²⁺→ ← Fe ³⁺process in, electronics transmission has hormesis to biochemical reaction, thereby biochemical reaction speed is increased.

Described biologic treatment process: the water outlet of hybrid reaction operation waste water after treatment after just sinking enters Aerobic Pond and carry out a biological disposal upon, and because the biodegradability of waste water is improved, makes COD, BOD remaining in waste water ₅can within very short time, obtain further degraded and remove, water outlet is qualified discharge after second pond precipitation again.

Enforcement of the present invention will obtain beneficial effect: resource is recycled, and the Mierocrystalline cellulose in wastewater from viscose fiber producing is recovered; Fixed investment reduces, and utilizes the characteristics and advantages of shallow air-floatation and iron dust filtration, makes construction investment and floor space all can save 1/3 compared with ordinary method; Production cost reduces, and calcium carbide breast waste liquid replaces milk of lime that dosage is greatly reduced, and expense saves nearly 2/3; Water quality after treatment can stably reach national grade one discharge standard.

Embodiment

Below in conjunction with embodiment, specific embodiment of the invention process is further described.

Get wastewater from viscose fiber producing, its water quality situation is as follows:

Wastewater from viscose fiber producing water-quality constituents

Implement by following process:

1, the composite waste that the acidity that the viscose fiber in stripping reaction process produces in producing and alkaline waste water are mixed to after pH=2.9 by 1: 2.5 proportioning enters stripping reaction tank, and acid out goes out to be in a large number the prezenta of suspension, most of H ₂s, CS ₂also be able to stripping removal Deng composition.

2, shallow air-floatation operation: the Rotatable water inlet water inlet tube through stripping reaction process former water after treatment from air flotation pool center, by rotation water distributing pipe water distribution, the translational speed of water distributor is identical with water inlet flow velocity, and the pond of air-floating apparatus is deeply generally no more than 650 mm.Water inlet stops 3～5min, and the removal efficiency of suspended substance can reach more than 85%.A large amount of Mierocrystalline celluloses are able to remove comparatively thoroughly and reclaim, and this had both reduced the pollution load of subsequent disposal, and the resource that has also realized prezenta reclaims.

3, iron dust filtration operation: air flotation pool water outlet has produced redox and electric attached collection effect through iron dust filtration, there is chain rupture dezincify reaction, the Fe that reaction produces in the principal pollutant in waste water ²⁺both can double as flocculation agent, making in post precipitation process needn't additional flocculating agents, can make again S residual in waste water ^2-mode with FeS precipitation is removed.

4, hybrid reaction operation: the water outlet of iron dust filtration tower enters bent neck groove and the abundant hybrid reaction of calcium carbide emulsion, then enters preliminary sedimentation tank precipitation.By the input amount of pH value automatic controlling system calcium carbide emulsion, pH value in reaction is controlled at 8～8.5, now the Zn in waste water ²⁺by thoroughly precipitation removal, the most Fe in waste water ²⁺also be precipitated removal.

5, biologic treatment process: the water outlet of hybrid reaction operation waste water after treatment after just sinking enters Aerobic Pond and carry out a biological disposal upon, and because the biodegradability of waste water is improved, makes COD, BOD remaining in waste water ₅can within very short time, obtain further degraded and remove, water outlet is the two water qualified discharges that settle out after second pond precipitation again.

The settle out water quality contrast of water of mixing water and two

Two heavy effluent qualities after treatment can stably reach national grade one discharge standard, have reclaimed the cellulose resource in waste water simultaneously, and its process facility is simple to operation, and can realize automatic production.

Claims (6)

1. a treatment process for wastewater from viscose fiber producing, its technical process is:

Stripping reaction process → shallow air-floatation operation → iron dust filtration operation → hybrid reaction operation → biologic treatment process.

2. the treatment process of a kind of wastewater from viscose fiber producing according to claim 1, it is characterized in that: after the acidity that the viscose fiber in described stripping reaction process produces in producing and alkaline waste water are mixed to pH=2～3 by proportioning, enter stripping reaction tank, acid out goes out to be in a large number the prezenta of suspension, most of H ₂s, CS ₂also be able to stripping removal Deng composition.

3. the treatment process of a kind of wastewater from viscose fiber producing according to claim 1, it is characterized in that: the Rotatable water inlet water inlet tube through stripping reaction process former water after treatment from air flotation pool center, by rotation water distributing pipe water distribution, the translational speed of water distributor is identical with water inlet flow velocity, the pond of air-floating apparatus is deeply generally no more than 650 mm, water inlet stops 3～5min, and the removal efficiency of suspended substance can reach more than 85%.

4. the treatment process of a kind of wastewater from viscose fiber producing according to claim 1, it is characterized in that: described iron dust filtration operation: air flotation pool water outlet has produced redox and electric attached collection effect through iron dust filtration, there are chain rupture dezincify reaction, pH=5～6 of waste water in the principal pollutant in waste water.

5. the treatment process of a kind of wastewater from viscose fiber producing according to claim 1, it is characterized in that: described hybrid reaction operation: the water outlet of iron dust filtration tower enters bent neck groove and calcium carbide emulsion or the abundant hybrid reaction of milk of lime, then enter preliminary sedimentation tank precipitation, by the input amount of pH value automatic controlling system calcium carbide emulsion or milk of lime, pH value in reaction is controlled at 8～8.5, now the Zn in waste water ²⁺by thoroughly precipitation removal, the most Fe in waste water ²⁺also be precipitated removal.

6. the treatment process of a kind of wastewater from viscose fiber producing according to claim 1, it is characterized in that: described biologic treatment process: the water outlet of hybrid reaction operation waste water after treatment after just sinking enters Aerobic Pond and carry out a biological disposal upon, COD, the BOD of remnants in waste water ₅further degraded is removed, and water outlet is qualified discharge after second pond precipitation again.