The paper industry occupies an important position in the national economy. The total discharge volume of China's paper industry is second only to the chemical and steel industry, ranking third in the industrial sector's wastewater discharge volume, and the COD emissions amount to one third of the total industrial COD emissions in the country. Therefore, the water pollution control in the paper industry has become a hot spot for the paper industry and even the whole society, and it has also become the key to the survival and development of papermaking companies. The use of waste paper compared with traditional paper, not only can save water, save energy, but also can reduce the amount of chemicals used to reduce pollution, and the recovery of waste paper itself is the recovery of waste management, so waste paper making papermaking industry development trend. According to the survey data of the National Paper Association, China's paper industry pulp pulp raw material has accounted for 63%.

　　Although the papermaking wastewater treatment equipment reduces the pollution generated by the wastepaper papermaking industry compared with the traditional plant fiber papermaking, it also generates a large amount of pollutants such as BOD, COD, SS, toxicity and color in the pulping and papermaking process. , High water consumption discharges high pollution loads, causing serious pollution problems to the water environment. With the increase of discharge standards and reuse water requirements, the disposal of waste paper papermaking wastewater has attracted more and more attention. The waste papermaking process includes pulping, bleaching, washing and papermaking. The main pollutants are pulping wastewater. Due to the differences in types, sources, treatment processes, and technical equipment of waste paper, there are also great differences in the characteristics of waste water discharged by different companies. The major sources of pulping wastewater are waste paper pulping, bleaching, and wastewater generated during the washing process. The wastewater has high COD and SS content, poor biodegradability, large chroma, and relatively low nitrogen and phosphorus pollution. Wastewater contains a large number of organic compounds with complex components. These organic materials consist of soluble slurries, chemical additives, and insoluble fibers. At present, there are 89 main organic pollutants reported in the literature, including alkanes, olefins, aromatic hydrocarbons, acids, esters, alcohols, phenols, and ketones. From the molecular weight distribution, the soluble COD components in papermaking wastewater are basically low molecular weight components with a molecular weight below 1 000 and high molecular weight components with a molecular weight above 100,000. In addition, there are many kinds of toxic substances in waste water, organic mainly include resin compounds, tannin compounds, chlorophenols, AOX (adsorbable organic halides), organic sulfides, etc.; inorganic toxic compounds are sulfur compounds. Mainly, such as sulfate, sulfite, hydrogen sulfide and so on.