Papermaking wastewater mainly comes from the two production processes of pulping and papermaking in the production of paper industry. Pulping is to separate the fibers from the plant materials and make them into pulp. After bleaching, a large amount of papermaking wastewater will be produced in this process; Papermaking is to dilute, shape, press and dry the pulp to make paper, which is also easy to produce papermaking wastewater. Common treatment methods: reverse osmosis, ultrafiltration, electrodialysis, etc