What should I do if the COD of the desizing wastewater in the printing and dyeing factory is too hig

Easy purification water network: desizing wastewater generally accounts for about 15 of the total amount of printing and dyeing wastewater, but the high concentration of pollutants accounts for about half of the total, the wastewater is alkaline, the pH value is about 12, the degree of pollution varies depending on the type of slurry, the desizing wastewater using starch slurry, COD and BOD values are very high, but the biodegradability is good, the desizing wastewater using chemical slurry, the COD value is high and the BOD value is low, and the biodegradability is relatively poor.

It can be adopted: flocculation process: under suitable flocculation conditions, add flocculant to the raw material liquid; The desizing wastewater is dark brown in color, and the pigments in it are mainly natural pigments.

Wastewater treatment problems can go to the ring. Protect. Tong**, I hope it helps you.

With composite decolorizing agent, the color of the wastewater can be reduced from the original 250 times to 30 times, the flocculated wastewater is light yellow, the pigment removal rate reaches 88%, and the decolorization effect is obvious.

Summary. 3 treatment methods of COD in pollution 1. Physical method: Generally, a flocculant is added to the waste, and then part of the pollutants are treated by a grille or other physical barrier, with some organic matter.

Page 1 Disadvantages: However, this method basically only works for COD concentrations of tens of thousands, and it is difficult to deal with when it reaches 100. 2. Property Law:

Sewage treatment is more transported, generally relying on a variety of strains, activated sludge and other substances, after aerobic anaerobic treatment, the formation of a complete treatment process, can effectively remove soluble and colloidal state of chemical organic matter. Disadvantages: However, the early adjustment of this method will consume a relatively large amount of investment.

3 treatment methods of COD in pollution 1. Physical method: Generally, a flocculant is added to the waste, and then part of the pollutants are treated by a grille or other physical barrier equipment, and some organic matter is eliminated with pants. Page 1 Cons:

However, this method basically only works for COD concentrations of tens of thousands, and it is difficult to deal with when it reaches 100. 2. Physical method: Pollution treatment is more, and the search and bending generally rely on various strains, activated sludge and other substances, and after aerobic and anaerobic treatment, a complete treatment process is formed, which can effectively remove soluble and colloidal state of chemical organic leakage.

Disadvantages: However, the early adjustment of this method will consume a relatively large amount of investment.

3. Chemical method: the oxidation of chemical agents decomposes organic matter, and the organic matter decomposition efficiency under this method is fast, and the processing time is fast. Page 2 Kuanshu "Adding Xijie's COD degrader can reduce the trace of COD in about 5 or 6 minutes, and the concentration is well adjusted, the flexibility is strong, and the COD can be well controlled by adding different doses according to different concentrations;

The printing and dyeing wastewater in the textile industry not only has a large amount of water, but also has high color and complex composition, and its wastewater mainly contains a variety of dyes, additives, acids, alkalis, inorganic salts, symbiotics and pigments removed from fibers and other impurities. These pollutants remaining in the printing and dyeing wastewater, in addition to copper, zinc, chromium, arsenic and other heavy metal inorganic ions, also contain dyes and their structures in nitro, aromatic amines, as well as additives, slurries and other organic matter and their intermediates, they all have great biological toxicity, serious pollution of the environment. The COD value of printing and dyeing wastewater can almost represent the amount of oxygen required for the oxidative decomposition of all organic matter in wastewater, so it is one of the most widely used important pollution indicators to indirectly represent organic matter in wastewater.

A large number of organic impurities such as co-organisms and pigments on dyes and intermediates, additives, slurries and fibers contained in printing and dyeing wastewater and some inorganic reducibles have caused printing and dyeing wastewater to have high color and high C0D value.

2.You're talking about 1000mg L of COD after treatment, and that's the big problem. 1000m l kill don't dare to platoon (normal grinding should be below 100mg l), if this is caught, it will die quietly.

I have a few suggestions, I don't know what to say, I can't say that I can't say that I am sleepy (haha!). Don't hit me! Isn't it a bit to Elder Tang!

1) It can increase the hydraulic retention time in the flocculation tank (it can reduce the flow rate of water, but it will affect the amount of water treated, but it is better than grasping it!) Increase the flocculant in an appropriate amount, and it is best to add a small amount of PAM to help coagulation after adding the flocculant, and the effect will be good. Generally, it is added when treating sewage.

except for low COD water ingress).

2) You can consider changing to other flocculants, I did an experiment on printing and dyeing wastewater when I was studying, and I forgot which flocculant was used at that time. You can find a few more flocculants to experiment, and the effect is better when different flocculants and different amounts are added.

I just graduated, and I just said some theoretical things, and the practical experience is not enough, so you can refer to it. 」

Below is an excerpt from a paper mill's EIA report.

Post a picture for you to see, I don't know what your specific COD is, if it is lower than this, you can try the "super effective shallow air flotation + aeration oxidation pond treatment process".

The wastewater treatment in the picture above is this process.

The process flow diagram is as follows.

The most commonly used methods are: adsorption method, microwave deep oxidation technology, chemical method, etc.

The adsorption method is the most widely used method in the treatment of printing and dyeing wastewater, which uses activated carbon, clay and other porous substances with large surface area to adsorb organic substances such as dyes and additives in printing and dyeing wastewater, so as to reduce the COD and chromaticity of printing and dyeing wastewater and achieve the purpose of purification, which is mostly used after biochemical treatment.

The use of powdered activated carbon can make the removal rate of wastewater C0D reach 93% 95%, and the removal rate of B0D can reach 95%.

96% with a chromaticity removal rate.

If activated carbon is used in combination with other methods, it can remove rotten mountains while maintaining a high C0D, and the color of the wastewater, B0D

The removal rate can also reach more than 80%. However, activated carbon adsorbents only have good adsorption performance for water-soluble dyes such as cationic dyes, direct dyes, acid dyes, and reactive dyes, while the adsorption of other organic substances such as hydrophobic dyes and suspended particles is not good, and the raw materials for activated carbon production are limited, and the regeneration cost is expensive, so it is generally only used in the advanced treatment of wastewater.

This is a reflection of the high content of soluble organic matter in water quality, and the conventional treatment method adopts anaerobic and then aerobic first, using biodegradable pollutants.

Finally, after many considerations, the engineers of Standard Group suggested adding COD degrader to the location of the original process sedimentation tank.

The detailed steps are as follows:

1) Dissolve the COD degrader into a 10% solution.

2) The diluted agent is dosed to the sedimentation tank with a metering pump.

3) Adjust the dosage appropriately according to the monitoring data until the sewage is stably treated and the dosage is determined

Finally, after on-site commissioning, the COD degrader was determined to be 1000ppm (COD can be controlled below 100ppm per ton of wastewater).

Dosing position: COD degrader can be directly added to the "sedimentation tank" in the original process, and the reaction time of the agent is effective in about 5 or 6 minutes, and there is no need to add additional equipment and processes.

Characteristics of wastewater from the coating industry.

1) The pollutant composition is complex and the pollutant content is high.

2) Wastewater contains toxic substances. Paint wastewater generally contains toxic organic substances such as phenolic and benzene.

3) The dispersion of wastewater pollutant content and water volume is large.

4) It is difficult to treat paint wastewater and the treatment cost is high.