The properties of the papermaking wastewater and treatment methods

2018/12/20 8:54:56

Mainly from paper industry wastewater treatment in pulp and papermaking industry in the production of pulp and writing two production process. Pulping is to separate the fiber in plant material, make pulp, then through bleaching; Writing is the dilution, forming, pressing, drying and made into paper. Both process discharge a large amount of waste water. Pulping wastewater, the pollution is most serious. When washing pulp effluent is dark brown, called blackwater blackwater high concentrations of pollutants in the BOD as high as 5 ~ ~ 40 g/l, contains a lot of fiber, inorganic salt and pigment. Bleaching process waste water discharge also contains large amounts of acid and alkali substances. Dipping paper mill waste water discharge, known as white water, which contains a lot of fiber and added in the production process of packing and rubber.
Disposal of wastewater from papermaking industry should concentrate on improving circulation water use ratio, reduce water consumption and wastewater emissions, at the same time should also actively explore a variety of reliable, economic, and can make full use of useful materials in waste water treatment. Such as flotation process section fibrous solid material in the recycling water, recovery rate can reach 95%, clear water reuse; Combustion method of recycling the blackwater, sodium sulfide, sodium sulfate and sodium cyanide oxidation in other sodium salt with organic matter.
Neutralization adjusting wastewater PH; Coagulation sedimentation or flotation process can remove suspended solids in the waste water; Chemical precipitation decoloring); Biological treatment can remove BOD of kraft paper wastewater treatment is effective; Wet oxidation method sulfite pulp wastewater treatment is more successful. In addition, both at home and abroad are using reverse osmosis, ultrafiltration, such as electrodialysis treatment method.