Pulp and paper industry

Paper, board and cardboard are made from pulp and, in part, from recovered paper. The wastewater produced mainly contains organic pollutants. After sufficient pretreatment, the biological treatment can take place in aerated lagoons or activated sludge plants. The temperature at the inlet to an activated sludge plant must not exceed 30–35 °C. For proper operation, the missing nutrients nitrogen and phosphorus must be added.