Process for treating waste paper pulping and papermaking waste water

Abstract

The invention relates to a process for treating waste paper pulping and papermaking waste water. The process comprises the following steps of: removing large-particle suspended matters from waste paper pulping and papermaking waste water through a grille well arranged at a discharge outlet, then feeding the waste paper pulping and papermaking waste water in a water collection tank, and pumping into a filtration system of an inclined screen device through a waste water lift pump; regulating and homogenizing the quality and quantity of waste water in a regulating tank, pumping water from the regulating tank into a horizontal-flow flotation tank through the lift pump, feeding a coagulant for coagulating sedimentation; feeding outflowing water of the horizontal-flow flotation tank into a middle tank, pumping a part of outflowing water into a workshop for reuse through a backflow pump, and pumping the rest part of outflowing water into an anaerobic tank; enabling the outflowing water of the anaerobic tank to an aerobic tank, enabling the outflowing water of the aerobic tank to a secondary sedimentation tank; enabling a part of outflowing water sedimented to flow in a recycling water collection tank and then pumped into the workshop for recycling; and enabling the other part of outflowing water to flow in a terminal discharge tank to reach the emission standard; enabling a part of biochemical sludge discharged from the secondary sedimentation tank to flow back to the aerobic tank, and enabling the other part of sludge to flow in a sludge thickening tank to be thickened, discharging supernatant of the secondary sedimentation tank into the regulating tank, and enabling the thickened filtrate to flow back into the regulating tank.

Description

technical field [0001] The invention belongs to the technical field of waste water treatment in the field of papermaking, in particular to a waste paper pulping and papermaking waste water treatment process. Background technique [0002] Papermaking is one of the four great inventions of the Chinese nation and an important achievement in the history of human civilization. In recent years, my country's paper industry has developed rapidly. The total consumption of paper and cardboard in my country is about 25 million tons, and the per capita consumption reaches 38 kg. [0003] As an important renewable resource, waste paper has good economic and social benefits and is of great significance to environmental protection and resource utilization. Using waste paper for pulping and papermaking can not only reduce deforestation, but also reduce the pollution caused by directly using raw materials for pulping. However, the content of COD and BOD in waste paper and papermaking waste...

AI Technical Summary

Problems solved by technology

If it is directly discharged into the receiving water body without treatment, it will cause serious pollution to the environment.

[0004] At present, the treatment of domestic papermaking (waste paper) wastewater adopts the traditional air flotation method to treat wastewater, focusing on partial recycling and making the treated water meet the standard discharge , resulting in unsatisfactory results in reduced wastewater discharge and treated water quality

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