In the process of papermaking wastewater treatment, black liquor, beating wastewater and white water are the key links.The treatment of papermaking black liquor is the key to papermaking wastewater treatment. At present, the commonly used papermaking black liquor treatment technologies include alkali recovery method and flocculation precipitation method.
Beating sewage: The sewage discharged from the pulper has the same composition as the black liquor, but the concentration is lower.Due to the small amount of organic substances (fiber and alkali, etc.) contained, it is difficult to recover, but the total solids, suspended solids and BOD5 in the sewage are still high, and the direct discharge is still very serious to the water pollution, so it needs to be treated.The main treatment methods include coagulation and sedimentation.
Applicable equipment
Papermaking sludge is dewatered by belt filter press, which can dewater sludge to a moisture content of 80%-85%; plate and frame filter presses and box-type filter presses can be dewatered to a moisture content of 75%-83%; With a diaphragm filter press, it can be dehydrated to a moisture content of 70%-78%;
Please contact us for the addition method of different equipments!
Selection of chemicals for papermaking sewage treatment:
The effectiveness of polyacrylamide in papermaking depends on its average molecular weight, ionic properties, ionic strength and other copolymer activities.The most important applications of polyacrylamide are in papermaking wastewater treatment (anionic polyacrylamide), fiber recovery and post-stage sludge dewatering (cationic polyacrylamide).
Medicine unit consumption
Polyaluminum chloride and anionic polyacrylamide are used in the pretreatment process of papermaking sewage treatment. According to the concentration of sewage, the dosage of the chemicals is different. The higher the concentration, the greater the dosage. The recommended dosage is about 10-15ppm (ie 0.01～0.015kg/ton wastewater).The consumption of cationic polyacrylamide for sludge dewatering in the latter stage is generally 3-6 kg.