Paper wastewater treatment equipment

 

 

details

 

In the process of papermaking, there is a lot of water. It takes 300~500m3 of water to produce 1t paper. In the waste water of papermaking, there is not only a large amount of papermaking raw materials (about 20% of the raw materials are lost with the waste water), but also a large amount of chemicals and other impurities.Therefore, if the paper wastewater is not disposed to discharge arbitrarily, it will cause great harm to the water body.

Characteristics of paper wastewater:
    1ã€?/SPAN>The waste liquor produced by cooking wood pulp (or straw pulp) is also called black liquor.
    2ã€?/SPAN>The sewage discharged from the pulping machine and the fine pulping machine is called the slurry sewage.
    3ã€?/SPAN>The waste water of the paper machine, which can be used directly, is called white water.
    There are several main types of pollution:
    1ã€?/SPAN>Suspended solids include settleable suspended solids and non-settleable suspended solids, mainly fibers and fibrous fine materials (i.e. broken fibrous fragments and mixed cells)
    2ã€?/SPAN>Biodegradable organic compounds include hemicellulose, methanol, acetic acid, formic acid and sugar with low molecular weight.
    3ã€?/SPAN> Refractory organic compounds are mainly derived from lignin and macromolecular carbohydrates in fiber materials.
    4ã€?/SPAN>Rosin acid and unsaturated fatty acid are contained in black liquor of toxic substances.
    5ã€?/SPAN>Ph value of caustic soda toxicant alkaline pulping wastewater is 9~10. Ph value of acid slurry is 1.2~2.0.
    6ã€?/SPAN>The residual lignin in chromaticity slurry wastewater is highly colored.
   SS and COD concentration of papermaking wastewater is high, while COD is composed of non-soluble COD and soluble COD. Generally, non-soluble COD accounts for the majority of the total COD composition. When SS is removed from sewage, most non-soluble COD is removed at the same time. Therefore, the main problem to be solved in waste water treatment of waste paper and paper is to remove SS and COD.
   Paper wastewater treatment process:
    (1)Adjust pool: the role of regulating pool is homogeneous and average, generally also can consider both precipitation, mixing, dosing, neutralization and acidification, and other functions, to adjust the water quantity and water quality, adjust the water pH value, water temperature, has the effect of pre aeration, the pool water agitation, oxygen filling, prevent suspended impurities precipitation, also can be used as a drainage accident.
    (2)After the contact oxidation pool: adjust the pool water gravity to touch the biochemical treatment, contact oxidation time can be up to 6 hours, packing for semi soft packing (namely for rigid plastic stents, above tied with soft fiber), it can prevent the growth of biofilm fiber forming spherical after reduce the specific surface area of the packing material, easy conjunctiva, no plug.
    (3)Sedimentation tank: after biochemistry, sewage flows to the sedimentation tank, which is inclined plate sedimentation tank. The slanting plate sedimentation tank USES the principle of anisotropic flow. The sludge water separation speed is fast, the water flow is stable and the separation effect is good,compared with other types of sedimentation tanks such as flat-flow ones, the separation rate and surface hydraulic load of sludge and water are both twice as high, and the sludge discharge is lifted to the sludge tank by air.
    (4)Disinfection tank and disinfection device: the disinfection tank USES mature ozone to disinfect, and the contact time of the disinfection tank is more than 12min.
    (5)Sludge tank: sludge is pumped into the sludge tank by sludge pump. The clean water from the sludge tank is returned to the contact oxidation tank for retreatment. The remaining sludge is very little, usually cleaned once every 1-2 years. The cleaning method can use a septic tank from the inspection hole of the sludge tank into the bottom of the sludge, for external transport.

Advantages of paper wastewater treatment equipment:
    1ã€?/SPAN>It deals with BOD5, COD, nh3-n, fecal e. coli and PH
    2ã€?/SPAN>The whole equipment can be buried in the ground without covering the surface area.
    3ã€?/SPAN>The noise is low, the odor is low, the impact on the surrounding environment is small
    4ã€?/SPAN>High degree of purification, less sludge production in the whole system;
    5ã€?/SPAN>High degree of automation, convenient management, no need for dedicated management;
    6ã€?/SPAN>Stable technology, easy maintenance
    7ã€?/SPAN>Low energy consumption, saving running cost