Reclamation and comprehensive treatment method for paper-making waste water

Abstract

The invention discloses a comprehensive processing method of paper-making wastewater reuse. By adopting the method, after being pre-processed, paper-making wastewater discharged enters ultra-filtration, reverse osmosis or nanofiltration; membrane permeation liquid can be directly reused for power plants or taken as process water; due to being rich in inorganic salt, various additives, lignin, fibrin, hemicellulose and other organisms, as well as various colonies, concentrated solution which is subjected to membrane interception can not be discharged directly. The concentrated solution is processed by adopting the microwave technique; the concentrated solution after being processed can achieve State Discharge Standards, thereby being discharged directly. Particularly, the pollution prevention and the recovery of a membrane system and the microwave treatment of the membrane concentrated solution can be discharged according to standards. A majority of paper-making wastewater can be reusedby adopting the method, and a small amount of residual wastewater can be discharged according to standards, thereby completely solving the problem that the water consumption is large in a paper-makingindustry.

Description

technical field [0001] The invention relates to a wastewater treatment method, in particular to a papermaking wastewater recycling comprehensive treatment method. Background technique [0002] The paper industry is a big water consumer and a big water polluter. According to statistics, my country's papermaking enterprises discharge about 3 billion tons of wastewater each year, accounting for about 15% of the national industrial wastewater discharge, ranking third; while COD emissions rank first in industrial emissions. Therefore, water resources and pollution control have always been one of the key factors restricting the development of my country's paper industry. According to the relevant national and provincial policies in 2007, the construction of new projects must comply with the requirements of total volume control and emission reduction. For paper companies that want to invest in new projects, the drainage per ton of paper must reach a higher level, and the recycling...

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Problems solved by technology

[0003] The traditional papermaking wastewater treatment technology is generally based on biochemical methods, combined with some physical and chemical treatment methods to achieve standard discharge. A very small amount of wastewater is only filtered by simple sand filter equipment for watering flowers and flushing toilets. Inorganic salts and dissolved organic matter cannot be removed by simple sand filtration equipment, and cannot be used as process water with high requirements. Membrane separation technology can completely solve the water quality problem of recycled water. In fact, most of the indicators are much higher than ordinary processes. Water requirements; however, due to the low B / C, high salt content, and poor biodegradability of the concentrated water separated by the membrane, its chemical oxygen consumption (COD) and other indicators cannot be treated and discharged by simple biochemical methods, which limits the membrane separation. As water reuse application

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