Composition and characteristics of the hottest pul

Components and characteristics of pulping wastewater

papermaking industrial wastewater refers to the wastewater produced in the process of pulping and papermaking. The production of paper industry is divided into two main process stages, namely pulping and 3 The zigzag process needs to make paper in a stable movement. Pulping is to separate the fibers from plant raw materials, make pulp, and then bleach; Papermaking is to dilute, shape, press and dry the pulp to make paper. Both processes consume a lot of water, most of which are discharged as waste water

pulping and papermaking wastewater can be roughly divided into pulping cooking liquid, washing wastewater, bleaching wastewater and paper machine white water. Alkali pulping waste liquor, also known as black liquor, is the main pollution source of pulp mills

the composition of pulping and papermaking wastewater is complex, and its composition depends not only on the method of pulp, but also on the product type. The calculation of engineering stress and the type of raw materials and other factors are analyzed and introduced in Jinan Ruima mechanical equipment Co., Ltd. Suspended substances in wastewater mainly come from fibers and fillers lost in pulping and papermaking processes; BOD mainly comes from pulping and cooking processes, such as sugars, alcohols, organic acids, etc. produced by cellulose decomposition. In chemical pulp, BOD5 of cooking waste liquid accounts for more than 80%; Cod and coloring substances mainly come from lignin and its derivatives in the pulping and cooking process

four main characteristics of pulping and papermaking wastewater:

1, high pollutant concentration. In particular, the pulping production line wastewater contains a large number of raw material dissolved substances and chemical additives, and its BOD5 concentration is even as high as 104mg/L

2. There are many refractory organic compounds with poor biodegradability. Lignin, cellulose and other substances are difficult to degrade by activated sludge method. For example, the BOD5 of the wastewater treated by some paper mills has been reduced to less than 10mg/l, but the COD is still up to 200mg/l to ensure lifelong technical services, and the chromaticity is still very high

3. The composition of wastewater is complex. In addition to the dissolved substances of raw materials, some also contain sulfides, inks, flocculants and other chemicals detrimental to biochemical treatment

4. Wastewater flow and load fluctuate greatly, accompanied by fiber and chemical spillage. This phenomenon is more obvious in factories with multiple production lines. The fluctuation of water volume and load is very unfavorable to the stable operation of biochemical treatment system