CN101921013A - Method for realizing reliable standard emission for electroplating wastewater by pure chemical precipitation method - Google Patents

Abstract

The invention relates to a method which can effectively process industrial nickeliferous electroplating wastewater by a pure chemical precipitation method, and is suitable for nickeliferous sewage treatment for industrial electronickelling, belonging to the technical field of environment protection in industrial production. In the prior art, an ion exchange method is used to process nickeling wastewater generated in industrial electroplating generally, which can not be used when nickeliferous amount in the wastewater reaches 5g/L. The above difficult problem can be easily solved by adopting the pure chemical precipitation method which comprises the steps of nickel ion neutralization by sodium hydroxide, segregation, precipitation and filter cake removal and has the chemical reaction formula as shown in the specification. The method has the following main technical points: 1, a precipitation tank after primary alkali addition is ensured to be uniform, and preferably, the pH value thereof is 9.7-10.5; and 2, the pH value of an outer drain tank is no less than 8.3.

Description

Realize the reliable standard emission of electroplating wastewater with simple chemical precipitation method

One, technical field: the environment protection of electroplating (casting) industry production

Two, suitable application area: the sewage disposal of industrial electro nickel plating

Three, background technology

Electroplate (casting) sewage and generally adopt ion exchange technique, nickel ion in the waste water and the sodium ion on the resin are exchanged and be removed, but this method has main two problems:

1, relatively is applicable to the less situation of nickeliferous ion ratio (nickel content is below 1g/L).For should dilute about 4 times about general nickel-plating liquid 5g/L, this will increase water consumption greatly, and the enterprise very big to original wastewater flow rate will be the problem of difficulty.

2, the exchange capacity of resin is low, and the regeneration period is short, brings certain difficulty to operational administrative.The device of exchange resin method is comparatively complicated with respect to simple chemical precipitation method device in addition.

Four, Fa Ming motivation and result

Hebei province's Zhuozhou City three ring textile equipment company limiteds that I am employed are the whole nation nearly 50 professional production textile printing and dyeings one of producers bigger in the printed nickel net.This factory produces per year surplus printed nickel net 100,000, and a year power consumption separates 1 ^#Ton has 10 of 1000L nickel baths, 5 of 1500L nickel baths surplus the nickel 100.Detected the discharge of wastewater severe overweight by environmental administration in 2004, if this problem does not solve the danger that enterprise faces closure.For this reason, we have visited many colleagues enterprise business organization, and visited Hebei province's Environmental Science Institute, and they have proposed the new concept of recycling economy, cleaner production, this theory is implemented in my unit, thereby makes the heavy metal in the water---and nickel ion content reduces greatly.Companies in 2005 have carried out the sewage water treatment method and the detection method up to standard of my invention again, and succeed, thereby authorized cleaner production demonstration enterprise by higher level department, and become sewage discharge enterprise up to standard, my invention moved 5 years continuously extremely now from 2005, and up to standard every year.

Five, summary of the invention:

Realize the reliable standard emission of waste water with simple chemical precipitation method

1, utilizes principle: Ni ⁺⁺Ion o'clock can precipitate substantially fully in pH value 〉=9.5.

2, chemical equation:

Six, technological process:

1, the precondition of technology execution: industry is done in the workshop will implement recycling economy, the new concept of cleaner production.With electroplating wastewater control within the specific limits.Promptly flow out pH value＞5.1～5.6 of waste water, Ni ⁺⁺Ion content＜5g/L, the method that reaches this point will be accomplished 2 points:

A, steep, wash the bigger water of acidity value such as filter cloth and want the individual curing reuse, can not make it enter waste water channel or pipeline.

The water of b, the flushing anode sludge, anode will be collected in the dedicated slot, and handles reuse, forbids that it enters channel or pipeline, in case a large amount of Ni ⁺⁺Ion is sneaked into waste water and is increased the difficulty of processing.

2, processing step.Have three links main the branch:

A, the first step are handled: electroplating wastewater is gathered into first treatment trough (pond) by special-purpose ditch or pipeline, treat that eight, ninety percent can fully stir and slowly add alkali lye (NaOH) after full, after pH value is near 9.5, note more, continuation slowly adds alkali under well-beaten situation.And the monitoring pH value of multifrequency time more, can stop stirring (whole churning time is no less than 20 minutes) after confirming all evenly to reach 9.7～10.5 and carry out quiescent setting more than 2 hours, when treating that groove (pond) water is so clear that you can see the bottom, earlier top limpid water is pumped into the 2nd settling bath with pump.

B, second step are continued precipitation: connect the first step and handle, continue to detect after static 2 hours its pH value, the water port pipe valve of apart from the bottom land higher position (about 250mm) is opened in its value＞8.2～9 o'clock, and the top limpid water of discharging is gone into the main discharge pipe net.

C, processing heavy wadding thing and mud.At first the heavy wadding thing of first treatment trough (pond) is pumped in the filter bag that is in directly over the groove (pond) with the chemical industry slush pump and staticly settles filtration, when throw out has been thicker mud, with the chemical industry slush pump mud is pressed in the filter again and carries out " making cake ", mud cake is taken out from pressure filter afterwards, it is pending to be placed on special concentration point again.The other second treatment trough bottom also has heavy wadding thing, pumps in the filter cloth bag with the chemical industry slush pump equally, staticly settles filtration, " makes cake " with being pumped into pressure filter after waiting to become mud, and the cake treatment process of producing is the same.

3, the concrete image of the condition of production is seen " Figure of description "-plating nickel screen sewage disposal synoptic diagram

4, technical essential: whole technological process should note following some:

A, when adding alkali, the stirring of first treatment trough (pond) must guarantee that its whole groove is even.For guaranteeing this point, it is bigger that the vortex pump of a stirring action answers gather to go out pressure.

B, under the situation of confirming to stir, monitor pH value, and confirm that its value accurately (determine by available several test paper contrasts, as using PH1～14, PH8.2～10, PH9.5～14, the contrast of three kinds of test paper) its numerical value is 9.7～10.5 for well, and is less than normal or excessive all bad, less than normal may be because of the insufficient and residual Ni of alkali number deficiency chemical reaction ⁺⁺Ion is too much; Thereby crossing conference causes the long influence production of sedimentation time normally to carry out

The standard of c, the outer draining of decision.The pH value that enters the water of outer network of drains should be between 8.3～9, if may be because of the alkali number deficiency below 8.3, and residual Ni ion be more; (should add alkali again and transfer pH value to 9～9.5 this moment in 2 settling baths (pond), and stir, leave standstill 1 hour afterwards after, can discharge).

5, other business:

The specification of a, treatment trough (pond).General settling bath (pond) for the first time should be designed to four, according to the effluent stream output of producing, generalized case is used just can guarantee to produce with two groove cycle alternations and is normally carried out, and two grooves (pond) are standby in addition, be used for improper situation, increase or occur groove once in a while as the short period of time aquifer yield and leak situation.

Two of b, attached more fine processing methods:

1., outer draining filtered by strainer once more after discharging again, can reach nickel content＜0.1mg/L

2., with outer draining again by δ-hydroxyquinoline resin, make nickel ion and its formation inner complex and separated, feasible outer draining contains nickel ion hardly.

Seven, description of drawings:

Fig. 1 electroplates nickel screen sewage disposal synoptic diagram (comprising front view and vertical view).Code name is among its figure:

1. be the settling bath second time;

2., 3., 4., 5. be the settling tank first time;

6. be the clear water plastic pump;

7. be the chemical industry slush pump;

8. be the whirlpool air pump;

9. be transition band and steel pipe frame;

10. it is pressure filter (containing the pressurized mud pump);

It is the sewage intake screen;

It is the sewage pipe trench;

Be waste pipe and valve;

It is the air pump vapor pipe;

It is once flexible plastic cement pipe of slush pump;

Be slush pump with the secondary flexible plastic cement pipe that draws water;

It is once flexible plastic cement blow-off pipe of slush pump;

It is the slush pump flexible plastic cement blow-off pipe of secondary;

Be fresh water pump with flexible plastic cement water shoot;

Be fresh water pump with flexible plastic cement water absorption tube;

It is outer blowoff basin;

It is the transition water layer;

Be the complete beds of precipitation;

It is the clear water layer;

It is the pipeline bottom valve.

Eight, embodiment:

This method Hebei province's Zhuozhou City three ring textile equipment company limiteds implement 5 years respond well and up to standard every year.Through higher level specialized department selective examination, detect with atomic absorption spectrophotometry, 5 years maximum values of outer draining are 0.27mg/L, (the national standard permissible value is 1mg/L), enterprise is survived like this, and has created condition for Sustainable development.The existing whole nation also has nearly 50 these patents of family once ratifying again to its popularization with the product industry.Other electronickelling industries can be adopted equally.

Claims (4)

1. utilize principle: Ni ⁺⁺Ion o'clock can precipitate substantially fully in pH value 〉=9.5.

2. whole technological processs:

1., the precondition of technology execution

2., three of processing step links (the first step is handled, second step was continued precipitation, handle heavy wadding thing and mud)

3., a of technical essential, b, c are three

3. Figure of description

4. subsidiary more meticulous treatment process a, the b in the other business is two.

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