Process for treatnig paper-making waste water of waste paper

Abstract

The treating process of waste water produced in making paper with waste paper includes the first stage of physical and chemical treatment with the apparatus of patent ZL 97114281.5 with aluminum sulfate added to the inlet as coagulant and acrylamide as coagulant aid; and the second stage of biochemical treatment in hydrolysis acidification-contact oxidation technique and perforation and flow dispersing aeration mode, with the waste water from biochemical treatment flowing into the secondary deposition pond. Of water after the first stage of treatment, 60-80 % is used as intermediate water returned to work shop, while other flows into the second stage of treatment for reuse in production or exhaust. The sludge from the first stage of treatment is treated in jigging sieve before reuse in production. The present invention may realize the closed circular use of paper-making waste water to reduce waste water exhaust.

Description

(1) Technical field [0001] The invention relates to sewage treatment technology, in particular to a closed cycle treatment method for waste paper and papermaking wastewater. (2) Background technology [0002] The paper industry has always been the main source of industrial pollution in my country, and the pollution caused by its wastewater accounts for one-third of all industrial wastewater pollution. Since the 1990s, due to the pressure of environmental pollution and ecological protection, the raw material structure of my country's paper industry has been greatly adjusted. Many enterprises have stopped making pulp and used waste paper as raw material to produce recycled paper. The reuse of plant fiber resources can also reduce the serious pollution caused by the direct use of plant raw materials for pulping. Waste paper and papermaking wastewater discharge mainly comes from washing, screening, concentration and paper machine white water and other processes. The characterist...

AI Technical Summary

Problems solved by technology

At present, the treatment of waste paper and papermaking wastewater mostly adopts primary physical and chemical treatment, mainly including sedimentation and air flotation treatment methods, but these methods have poor treatment effects, and it is difficult to meet the discharge standards required by the country. Some factories also use primary physical and chemical treatment. Secondary biochemical treatment is adopted, but this method requires large investment, high operating costs, and a large amount of equipment maintenance, which is difficult for ordinary paper mills to bear

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