New technology for wastewater treatment of steel drum water-based paint
Foshan Nanhai Yilin Chemical Co., Ltd. Wan Lianghua
Wan Lianghua speaks at Guilin Steel Bar Industry Conference
Our company's main metal surface pretreatment materials: degreasing powder, phosphating agent, zirconating agent. The post-treatment materials are: high-quality products such as paint removal agent AB, water-based paint scavenger, and so on.
In response to the national call for energy conservation and emission reduction, after years of research, we have researched the main new product in 2016: “Water-based paint scavengerâ€, which is a water-based paint wastewater treatment material. This product has registered trademarks and Obtained national patents! It is the best material for treating water-based paint wastewater!
First, the contrast of different paints of water-based paint and paint
Everyone knows the strict requirements of the country for environmental protection. Everyone knows the future demand for water-based paint in the barrel industry, and the inevitability of water-based paint to replace oil paint. At present, the implementation of stepped VOCs for sewage charges across the country may greatly promote the transformation of the steel drum industry and the coating industry to “oil to waterâ€. With the increasing intensity of the “environmental stormâ€, it is imperative for the coating industry to “oil to waterâ€. The table below shows the application comparison between water-based paint and traditional paint:
Comparison of the application of water-based paint and traditional paint in steel drum
Comparison itemWater-based paint
paint
product composition
Waterborne resin, water solvent, pigment and filler
Synthetic resin, organic solvent (benzene), TDI, pigment and filler
safety
Storage application: non-combustible
Storage application: flammable and explosive, especially thinner
Gas emission pollution
Gas emissions are non-polluting water vapor bodies, no treatment is required, and emissions are up to standard
Gas emissions are highly polluting organic gases, which are not up to standard after treatment
Liquid discharge pollution
Liquid discharge is a harmless aqueous solution, no treatment is required, and emissions are up to standard
The liquid discharge is a highly polluting organic solution, and the discharge is not up to standard without treatment.
air quality
The product application has no irritating odor, and the product application environment has good air quality.
Product application produces high concentrations of irritating odors, poor ambient air quality
Dilution cost
Water dilution, very low dilution cost
Dilution with organic solvent, higher dilution cost
Coating rate
140-150 barrels per 20 kg
120-140 barrels per 20 kg
Color change, cleaning
Clean water cleaning, basically no cost
Organic solvent cleaning, higher cost
Today I am going to talk about the pollution comparison between oil paint and water-based paint and the solution!
Second, the comparison of water-based paint and paint wastewater treatment methods
The main pollution of oil paint comes from solvent organic matter, polluting the air environment, and the pollution of water falling in the water. This is a convenient way to solve it. Treated with AB suspension.
Water-based paints are characterized by water solubility, which is solvent-free or solvent-free. Reduced VOC emissions and reduced air pollution. However, because of the water-soluble characteristics, the water-based paint is completely dissolved in water when it falls in water. This is a hydrophilic chemical material, which causes more water pollution than oil paint. It is much more difficult to treat wastewater contaminated with water-based paints.
At present, the methods that everyone knows or have tried have been: 1 mechanical filtration method, 2, wastewater treatment precipitation method, 3. inertial method AB suspension agent for treating oil paint. So, do you think that there are the following situations? Either the treatment is not clean, or the color can't be removed. I don't know how many medicines to add to the effect. I don't know when the medicine will be added. The unprofessional person can't handle the law. I don't know why. OK, this time the same waste water, the same waste water, the same treatment method can not be the same effect, can not be copied.
1. Paint wastewater treatment method
(1) Use the paint remover C-107 to adjust the pH of the water to 8.5-9 at a certain point in the circulating water tank (or water curtain cabinet) (you can choose manual adjustment when there is no dosing machine).
(2) Using the paint remover A-105 (about 5 kg) in the inlet of the circulating water tank (or water curtain cabinet) to crack the paint in the water. (When there is no dosing machine, you can choose to manually add and start to stir with the trachea when starting work).
(3) Use the paint remover B-106 (about 5 kg) to condense and float the paint in the water at the water outlet of the circulating water tank (or water curtain cabinet). (If there is no dosing machine, you can choose to add it directly and use the trachea to stir the gas half an hour before the work is completed. If necessary, add a small amount of paint remover C-107 for pH adjustment).
(4) Remove the paint residue regularly and change the water regularly.
2. Traditional wastewater treatment method for water-based paint
(1) The conventional wastewater treatment agent is subjected to reduction treatment and then diluted with a large amount of water to treat its color odor.
(2) It is treated by the habitual treatment of the organic solvent type paint, that is, the agent A is used to break the viscosity, and the agent B is suspended.
(3) It is treated by mixing and filtering with special large equipment and chemicals.
The first method, complicated and troublesome, consumes a large amount of chemicals and water resources; the effect is not obvious.
The second method, the completely non-conforming treatment method, can not control the parameters, can not handle the water-based paint, and the cost is also high; the visible effect is that only a small amount of resin components in the water-based paint wastewater will be separated and suspended, and cannot be completely effective. The water-based paint color suspension and other components in the water are treated; the operation is complicated, and the parameters to be controlled are too fine to be accepted by the field operator.
In the third method, the treated water quality can also meet the industrial wastewater discharge standard, but the production cost of the equipment is high, the floor space is required, and the system to be processed is complicated.
3. Common problems in traditional water-based paint wastewater treatment
Common situation
â—Ž Either the treatment is not clean, or the color cannot be removed;
â—Ž I don't know how much medicine to add to the effect;
â—Ž I don't know when to add the medicine to produce the effect;
â—ŽUnprofessional people can't handle it, can't find the law;
◎ I don’t know why I was able to do it last time, this time the same waste water;
The same waste water of the same medicine, the same treatment method can not be copied without the same effect.
Not energy efficient, difficult to operate, unprofessional, uncontrollable, unstable, inefficient, and not environmentally friendly.
Third, scavengers - the magic weapon for water-based paint wastewater treatment
It is precisely because of these uncertain factors, these problems, these pain points are developed products. Energy saving, emission reduction, easy operation, direct, specific, controllable, stable, efficient and environmental protection are the characteristics of the scavenger.
For water-based paints. The scavenger can measure the solid content of the water-based paint in water by the spotting method, and according to the ratio of the solid content, the number of scavengers to be used can be calculated. Then, according to the calculated amount of scavenger, the continuous addition of the water-based paint can be carried out by separating the solid content of the water-based paint in the water, floating on the water surface, and directly picking up. Still water is a true color.
We have already reported the data in the third party, and the COD and BOD in the wastewater have also decreased accordingly. You can continue to recycle industrial use, you can also carry out the next process, discharge!
1. Characteristics of scavenger treatment of wastewater
â—ŽSimple: A single agent can be used by ordinary employees.
â—Ž Direct: Treat the water-based paint color and suspended matter in the water to make the wastewater clear, transparent and odorless;
â—ŽSpecial: single agent, clear usage, no waste, only for water-based paint, no side effects;
â—Ž Controllable: Clear data, controllable proportion, can be accepted by any field operator;
â—Ž Stable: Adding medicines by using an automatic dosing machine to save the amount of medicine used and ensure continuous and effective;
â—Ž Efficient: 1% use, water-based paint in high-efficiency reaction water;
â—ŽEnvironmental protection: The material is imported from Germany, and it is environmentally friendly, reducing the COD of wastewater and creating environmental protection;
2, using the scavenger processing method
(1) Firstly, the PH value and Q value of the wastewater are detected.
(2) According to the Q value, the total amount of scavenger chemicals (total wastewater * Q value) that should be used in the entire wastewater pool can be calculated.
(3) Adjust the pH value of 8.5-9.5 in the wastewater tank.
(4) Then, with the addition of the scavenger agent to be added slowly with air blowing or stirring, the entire paint of the waste water can be suspended at the upper end of the pool.
(5) If the water quality is not clear, the pH value is wrong. The pH should be adjusted to 6.5.
3. Method for determining water-based paint solid content in waste water
(1) Remove 300 ml of wastewater from the wastewater collection tank and measure the pH value to adjust the pH to 8.5-9.5.
(2) Add and shake with the test agent, and wait until the 300 ml of the wastewater is completely clarified, and see the number of milliliters of the test reagent used.
(3) The amount of test reagent consumed is divided by 300, which is the Q value of the paint content of the waste water. (The significance of the Q value is to calculate the effective water-based paint content of the waste water).
Water-based paint wastewater before treatment
Treated water-based paint wastewater
Fourth, the case analysis
Guangdong Zhongcheng Chemical Co., Ltd. is a subsidiary of Dongguan Zhenhua Special Packaging Co., Ltd., which has been using water-based paint for more than ten years. The average monthly water-based paint is about 5,000 kg. Most of the paint in the production process has been recycled. Used, but the spray booth, spray cabinet, spray gun will still cause a lot of water-based paint wastewater, about 10 tons per month. The water-based paint content is about 300 kg.
They used to use the common waste water treatment method, using the ferrous sulfate sulphate for reduction treatment and then diluting its color and odor with a large amount of water. After a day's reaction, the waste water will turn black and become odorous; more than half of the slag will be deposited at the bottom of the pool, then the black water will be placed in the water treatment system, and then diluted with about 20 tons of other wastewater or tap water. Color, and finally collective wastewater treatment, can barely meet emission standards. The process is complicated, the cost is large, and the effect is very unsatisfactory.
Water-based paint wastewater treatment site
1. The actual situation of the enterprise
The average monthly use of water-based paint is 5,000 kg, and most of the paint has been recycled. The spray booth spray nozzle and spray gun waste water are 10 tons, and the water-based paint content is 300 kg.
2, using ordinary wastewater treatment method (300 kg of ferrous sulfate for reduction)
The treatment method is as follows: after one day's reaction, it turns black and becomes odor; about half of the slag is deposited at the bottom of the pool, black water needs 20 tons of tap water to dilute its color, and finally, collective wastewater treatment is carried out to barely reach the discharge standard. . The process is complicated, the cost is large, and the effect is not satisfactory.
3, using the scavenger processing method
(1) The test before use is carried out, and the PH value is 5 and the Q value is 1/15.
(2) Then adjust the PH to 8.5.
(3) Waste water 10000 kg * 1 / 15 = 600 kg of scavenger pharmacy, air pump agitation.
(4) After half an hour, the waterborne paint in the water floats on the surface.
(5) The on-site staff took 600 kg of paint residue and dried it, and the rest was water.
(6) The color of water restores the color of tap water and is directly discharged into the ordinary wastewater treatment system without dilution.
The results confirmed that the effect of using the scavenger is very satisfactory. Our company has directly received the leadership of Zhenhua Company, and even the leadership of Zhongcheng Company and the local environmental protection department.
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