Why is papermaking so polluting and does not treat sewage

Water treatment should be carried out according to regulations. Otherwise, the paper mill should be closed. But the local environmental protection department can't do it. There are so many things involved.

Basically, they will be forced to install, but it depends on whether the leader will come or not.

Paper mill effluent generally contains high concentrations of organic matter, suspended solids, color, nitrogen and phosphorus, etc., and requires special treatment. Here are a few paper mill wastewater treatment methods:

Biochemical treatment: The paper mill wastewater is passed through biochemical treatment units such as aeration tanks, aerobic tanks and anaerobic tanks, and microorganisms are used to degrade organic matter and nutrients such as nitrogen and phosphorus, and relatively clean effluent is obtained. The treatment effect of this method is stable and the operating cost is low.

Flocculation and sedimentation method: By adding flocculant, the suspended solids, chromaticity and other solid impurities in the coincidental sewage are condensed into large particles, and then they are separated and removed by sedimentation tanks and other equipment. This method is suitable for the treatment of paper mill wastewater containing a large amount of suspended matter.

Membrane separation technology: Ultrafiltration, nanofiltration and other membrane separation technologies are used to separate, concentrate and remove specific dissolved substances from the wastewater of the Zhuzhi paper mill. This method has excellent treatment effect and high effluent quality, but it has high requirements for equipment and relatively high construction cost.

As far as I know, the integrated sewage treatment device with oxygen H3MBR independently developed by Evergrande Xingye Environmental Protection can meet the sewage treatment needs of paper mills. Specifically, please consult the function of the product in detail.

It is necessary to choose the corresponding treatment method according to the specific characteristics and economic conditions of the sewage, and the single or multiple methods can be used for combined treatment to achieve better treatment effect and cost saving.

Because the pollutants contained in the papermaking wastewater itself are very complex, it is a kind of industrial wastewater that is difficult to treat, and the main pollutants of the wastewater are, there are suspended flocculents, papermaking fiber fragments, COD, color, SS, etc., and it is illegal to discharge the water of the papermaking workshop without treatment. Therefore, the use of sewage treatment equipment to treat the sewage generated by paper mills is an effective measure.

Paper mill wastewater treatment method process.

1. After the wastewater enters the wastewater treatment system, the larger debris is separated through the wastewater barrier grid, enters the grid pool, and enters the coagulation tank.

2. The addition of polyaluminum chloride and polyacrylamide will produce a coagulation reaction.

3. Air flotation method to remove SS and part of BOD in wastewater.

4. The air float water can enter the anaerobic and aerobic poles for biochemistry to remove most of the BOD and COD of the water.

5. After being treated by the secondary sedimentation tank, the COD and chromaticity of the wastewater cannot meet the national discharge standards, and the discharge by chemical coagulation method meets the standards.

6. The addition of sewage decolorizer can achieve the decolorization, flocculation and sedimentation of wastewater.

The paper industry is a light industry with large output, large water use and serious pollution;

If the wastewater of the paper industry is discharged into the river without treatment, the organic matter in the wastewater will be fermented, oxidized and decomposed, which will consume oxygen in the water and cause death of aquatic organisms such as fish and shellfish due to lack of oxygen; Some fine fibers are suspended in the water, which is easy to clog the gills of fish and also cause fish death;

The bark chips, wood chips, grass clippings, rotting weeds, and putrid slurry in the wastewater sink to the bottom of the water, silting up the riverbed, and constantly producing toxic odors in the slow fermentation; There are also some substances in the wastewater that are not easy to ferment and decompose, which are suspended in the water, absorb light, reduce sunlight penetrating into the river water, and hinder the photosynthesis of aquatic plants.

Summary. Hello! Build a sewage treatment facility and treat the sewage to meet the national discharge standards before discharging.

Effluent from paper mills is easy to treat. Physical methods, filtration and precipitation methods to remove solid pollutants; Then chemically, add some flocculant in the precipitation; Then biological methods, get a biological oxidation pond or something, and dispose of heavy metals and some ions or something. And then it's basically up to the mark.

Hello! Build a sewage treatment facility and treat the sewage to meet the national discharge standards before discharging. Effluent from paper mills is easy to treat.

Physical methods, filtration and precipitation methods to remove solid pollutants; Then chemically, add some flocculant in the precipitation; Then biological methods, get a biological oxidation pond or something, and dispose of heavy metals and some ions or something. And then it's basically up to the mark.

I mean, the water is flowing into the field, what to do with it?

The sewage decolorizer of the paper mill can be added to the sewage tank.

Add the decolorizer of the paper mill wastewater directly to the field.

Treatment technology: SN ozone catalytic oxidation coupling reaction technology can completely solve the SS and COD in wastewater, and easily reduce it to the wastewater treatment standard. The SAO3-II high-efficiency water treatment catalyst technology is used to greatly improve the degradation speed and efficiency of residual organic matter in wastewater through enrichment-catalytic activation-oxidative degradation, and combine the strong oxidation of [OH·] with the enrichment and catalytic activity characteristics of the catalyst, so as to more effectively solve a series of problems such as low efficiency and high operating cost of catalytic oxidation treatment.

Pulp and paper making all discharge a large amount of wastewater. The wastewater produced by pulping is the most polluted. The wastewater discharged during pulp washing is black-brown, called black water, and the concentration of pollutants in black water is very high, with BOD as high as 5-40g L, containing a large amount of fiber, inorganic salts and pigments.

The wastewater discharged from the bleaching process also contains a large amount of acids and alkalis. The wastewater discharged from the paper machine, called white water, contains a large amount of fibers and fillers and rubbers added during the production process.

The main types of pollution contained in paper mill effluent are as follows:

1. Suspended solids include settleable suspended solids and non-settleable suspended solids, mainly fibers and fiber fines (i.e., broken fiber fragments and miscellaneous cells).

2. Easily biodegradable organic compounds include low molecular weight hemicellulose, methanol, acetic acid, formic acid, sugar, etc.

3. Refractory to biodegradable organic matter is mainly based on lignin and macromolecular carbohydrates contained in fiber raw materials.

4. Toxic substances: rosin acid and unsaturated fatty acids contained in black liquor.

5. The pH value of alkali slurry sewage is 9 10; The pH value of acid pulping wastewater is.

6. Chromaticity The residual lignin contained in the pulping wastewater is highly colored.

The treatment of wastewater in the paper industry should focus on improving the recycling rate, reducing water consumption and wastewater discharge, and at the same time, various treatment methods that are reliable, economical and can make full use of the useful resources in wastewater should be actively explored. For example, the flotation method can be used to improve the fibrous solid matter in white water, with a rate of up to 95%, and the clarified water can be reused; The combustion method can ** sodium hydroxide, sodium sulfide, sodium sulfate and other sodium salts combined with organic matter in black water.

The neutralization method regulates the pH value of wastewater; Coagulation sedimentation or flotation can remove suspended solids from wastewater; Chemical precipitation can be decolorized; The biological treatment method can remove BOD, which is more effective for kraft paper wastewater. The wet oxidation method is more successful in treating sulfurous acid pulp wastewater. In addition, reverse osmosis, ultrafiltration, electrodialysis and other treatment methods are also used at home and abroad. Discharge up to standard.

The sewage water volume of the paper mill is generally very large, the amount of fiber is high, it belongs to the light industry with serious pollution, and because of the bleaching process, the pollution components in the water are more complex, not only to deal with the color of the sewage, but also to deal with the odor problem in the sewage, so this kind of wastewater needs to use decolorizers and deodorants. Decolorizer treats color impurities in sewage, and deodorant treats odors such as hydrogen sulfide, ammonia, and ethyl mercaptan in sewage.

Sewage treatment roots blower uses:

In the wastewater treatment industry, since the wastewater pond must carry oxygen for microbial oxidative decomposition, in the field of wastewater treatment, roots blowers can be based on the difference in water depth and the tonnage of the treated water. Provides a quantitative amount of oxygen to promote the oxidative decomposition of microorganisms.

The three-leaf roots blower is the core equipment of sewage treatment. The efficiency of the fan can directly determine the effect of wastewater treatment. Biological treatment of wastewater to promote the growth of aerobic microorganisms must provide sufficient oxygen, aerobic microorganisms can promote the emergence of metabolism, the decomposition of suspended solids in wastewater and the decomposition of organic compounds such as nitrogen and phosphorus.

The paper industry is a light industry with large output, large water use and serious pollution; If the wastewater of the paper industry is discharged into the river without treatment, the organic matter in the wastewater will be fermented, oxidized and decomposed, and the oxygen in the water will be consumed, so that fish, shellfish and other aquatic organisms will die of hypoxia, and some fine fibers will be suspended in the water, which is easy to block the gills of the fish and cause fish death. The bark chips, wood chips, grass clippings, rotting weeds, and putrid slurry in the wastewater sink to the bottom of the water, silting up the riverbed, and constantly producing toxic odors in the slow fermentation; There are also some substances in the wastewater that are not easy to ferment and decompose, which are suspended in the water, absorb light, reduce sunlight penetrating into the river water, and hinder the photosynthesis of aquatic plants.

Paper Mill Waste Gas Treatment Program:

1. The odor generated in the pulping production process: it will be sent to the alkali boiler for combustion through a completely sealed conveying system.

2. Waste gas generated by pulp bleaching and preparation of chemical reagents: After chemical treatment in the exhaust gas scrubber, it is transformed into a gas that does not pollute the air, and then discharged into the atmosphere.

3. Dust generated by the combustion of power boilers, alkali boilers and lime kilns: Efficient electrostatic precipitators are set up before combustion exhaust gas discharge to remove the dust in the limb rot front. <>