CN103086540A - Method for flocculating concentrated wastewater from banknote printing works - Google Patents

Abstract

The invention relates to a method for flocculating concentrated wastewater from banknote printing works, which belongs to the technical field of industrial wastewater treatment. The method disclosed by the invention comprises the following steps: firstly, adding a flocculating agent into concentrated liquor from banknote printing works, and fully stirring the obtained mixture so as to completely dissolve the flocculating agent into the concentrated liquor from banknote printing works; then, adjusting the pH value of mixed liquor to be 7.0-8.0 so as to enable the mixed liquor to generate a large amount of small flocs; and finally, adding an organic coagulant into the mixed liquor, then stirring and reacting the obtained mixture so as to sufficiently agglomerate the flocs, thus completing the flocculation processing. A flocculated precipitate prepared by using the method disclosed by the invention is small in viscosity, and can be forcedly dewatered by using a centrifugation method and a filter-pressing method and other methods, and further the production of solid slag is alleviated; no chloride ion is brought in the process of flocculation, thereby preventing the corrosion of stainless steel pipes and equipment; the flocculating agent is an aluminum flocculating agent which is easily available and cheap; and the flocculation effect is stable, and the liquid supernatant is clear.

Description

A kind of flucculation process of wiping paper money printing plate concentrating spent liquor

Technical field

The present invention relates to a kind of flucculation process of wiping paper money printing plate concentrating spent liquor, belong to the technology for treating industrial waste water field.

Background technology

The wiping version waste liquid that produces in the bank-note gravure printing production process contains the materials such as a large amount of alkali, tensio-active agent and printing ink.According to statistics, the annual wiping version waste liquid that produces of China reaches the hundreds of thousands of ton, wherein the wiping version waste liquid of 80% left and right is back to industrial production by techniques such as ultrafiltration with the form of crossing cleaner liquid, and the materials such as printing ink are enriched among the concentrating spent liquor (abbreviation dope) of residue 20%.Classification according to trade effluent, the wiping paper money printing plate dope belongs to the special dyeing waste water of a class, its principal character is: high emulsibility, strongly hydrophilic, Pollutant levels are high, complicated component, colourity are dark, toxicity greatly, readily biodegradable not, be a kind of unmanageable trade effluent.Due to the singularity of seal paper money industry, and other dyeing relatively, wiping paper money printing plate dope proportion is less, therefore the research and development of wiping paper money printing plate dope treatment technology is not obtained general attention all the time, and available technological method is very limited.

Traditional wiping paper money printing plate dope treatment process is directly to burn, and in 10% left and right, the integral combustion calorific value is not high due to the solids content of concentrated solution, and therefore, burning method is comparatively power consumption not only, every burning 1m ³The fuel cost of concentrated solution just reaches 200 yuan of left and right, and can produce a large amount of atmospheric polluting materials, causes secondary pollution.Present domestic seal paper money corporate boss will adopt the methods such as sulfuric acid neutralization, calcium chloride breakdown of emulsion to carry out pre-treatment to wiping the version dope, on the one hand the principal pollutant precipitatings such as printing ink in dope are separated, reduce whole processing cost and environmental pollution of burning, on the other hand the bio-toxicity of supernatant liquor is significantly reduced, biodegradability improves, thereby satisfies general biologic treating technique to the requirement of raw water quality.But the general problem that these pretreatment processs exist is: in and precipitating thing viscosity large, easily cause the sticking stifled of e-quipment and pipe, be difficult for adopting belt or plate-and-frame filter press further to dewater; The calcium chloride breakdown of emulsion will be brought a large amount of chlorions into, corrosion stainless steel pipes and equipment.

Summary of the invention

The objective of the invention is the problem that exists in order to solve above-mentioned wiping paper money printing plate concentrating spent liquor in preprocessing process, proposed the pretreated flucculation process of a kind of suitable wiping paper money printing plate concentrating spent liquor.

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

The flucculation process of wiping paper money printing plate dope of the present invention, its concrete steps are:

1) at first add flocculation agent to the wiping paper money printing plate dope, stirring reaction 5～10min under the rotating speed of 40～100r/min is dissolved in the wiping paper money printing plate dope flocculation agent fully.

2) the application quality mark is that 30～50% sulphuric acid solns will be through step 1) the pH value of mixed solution after processing is adjusted between 7.0～8.0, and the pH value adjusting time makes a large amount of small flco of mixed solution generation more than 20min.

3) to through step 2) mixed solution after processing adds organic coagulant aids, and stirring reaction 60～180s under the rotating speed of 40～100r/min makes the abundant agglomerate of flco, and flocculation treatment is completed.

Step 1) flocculation agent described in is Tai-Ace S 150, polyaluminium sulfate, PAFS or its arbitrary combination, and in reaction solution, the final total mol concentration of ferro-aluminum is 90～150mmol/L, and aluminium content is not less than 20mmol/L.

Step 3) the organic coagulant aids that adopts in is anionic polyacrylamide, and degree of hydrolysis is 20～30%, and ultimate density is 20～40mg/L in reaction solution.

Beneficial effect

The flocculate precipitate viscosity that adopts flucculation process of the present invention to produce is little, and the methods such as available centrifugal, press filtration are carried out strengthen dewatering, further reduce solid slag output; Do not bring chlorion in flocculation process into, prevent from causing the corrosion of stainless steel pipes and equipment; Flocculation agent is the aluminium based flocculating agent, is easy to get inexpensive; Flocculating effect is stable, and supernatant liquor is limpid.

Description of drawings

Fig. 1 is the schematic flow sheet of flucculation process of the present invention.

Embodiment

Below in conjunction with drawings and Examples, content of the present invention is described further.

Embodiment

Take certain seal paper money company wiping paper money printing plate dope waste water as processing object, its parameters is: temperature is 48 ℃, and total solid holdup is that 10.5%, SS is 20g/L, and CODCr is 130g/L, 15000 times of colourities, pH＞13;

Adopt method of the present invention to carry out flocculation treatment to above-mentioned wiping paper money printing plate dope waste water, concrete treating processes is as follows:

1) at first add Tai-Ace S 150 to the wiping paper money printing plate dope, making the aluminum ion volumetric molar concentration is 110mmol/L, and abundant stirring reaction 5min, be dissolved in the wiping paper money printing plate dope flocculation agent fully under the rotating speed of 80r/min.

2) using concentration is that 45% sulphuric acid soln will be through step 1) progressively to be adjusted to 7.2, the pH value adjusting time be 25min for pH of mixed value after processing, makes a large amount of small flco of mixed solution generation.

3) to through step 2) to add degree of hydrolysis be 25% anionic polyacrylamide for mixed solution after processing, making the ultimate density of anionic polyacrylamide in reaction solution is 30mg/L, make the abundant agglomerate of flco, form better flocculating effect, flocculation treatment is completed.

After adopting method of the present invention to carry out flocculation treatment to above-mentioned wiping paper money printing plate dope waste water, natural sedimentation 10min, the total solid holdup of supernatant liquor is 2.7%, SS=48mg/L, COD _CrBe 7600mg/L, colourity=50, pH is 7.2.

Claims (1)

1. the flucculation process of a wiping paper money printing plate concentrating spent liquor is characterized in that concrete steps are:

1) at first add flocculation agent to the wiping paper money printing plate dope, stirring reaction 5～10min under the rotating speed of 40～100r/min is dissolved in the wiping paper money printing plate dope flocculation agent fully;

2) the application quality mark is that 30～50% sulphuric acid solns will be through step 1) the pH value of mixed solution after processing is adjusted between 7.0～8.0, and the pH value adjusting time makes a large amount of small flco of mixed solution generation more than 20min;

3) to through step 2) mixed solution after processing adds organic coagulant aids, and stirring reaction 60～180s under the rotating speed of 40～100r/min makes the abundant agglomerate of flco, and flocculation treatment is completed;

Step 1) flocculation agent described in is Tai-Ace S 150, polyaluminium sulfate, PAFS or its arbitrary combination, and in reaction solution, the final total mol concentration of ferro-aluminum is 90～150mmol/L, and aluminium content is not less than 20mmol/L;

Step 3) the organic coagulant aids that adopts in is anionic polyacrylamide, and degree of hydrolysis is 20～30%, and ultimate density is 20～40mg/L in reaction solution.

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