Biological pulp and paper making wastewater zero discharge technique

Abstract

The invention relates to a biological pulp and paper making wastewater zero discharge technique, which belongs to the technical field of paper making. The invention mainly improves the procedures of cooking and middle section water treatment. The cooking procedure adjusts the cooking technique, reduces the cooking pressure and shortens the cooking time, thereby effectively reducing the pulp extract and reducing the COD content in middle section water; and the middle section water treatment procedure modifies the rotary mixing type aerator in the bioaeration pool into a suspension-type aeration chain device, thereby enhancing the oxygen conversion efficiency by 5-10%, increasing the dissolved oxygen content in wastewater and enhancing the organic matter removal rate in wastewater on the premise of not increasing the power. The invention breaks through the normal procedure for the middle section water treatment, and treats the middle section water twice, so that all the treated water can be recycled. The invention realizes cyclic utilization of black liquor and zero discharge of middle section water, solves the problem of large amount of clear water of the paper machine, saves the water resources, reduces the environmental pollution and provides successful experience for non-xylogen paper making.

Description

technical field [0001] The invention belongs to the technical field of papermaking. Background technique [0002] At present, due to the difficulties in pollution control and the optimization and adjustment of the national paper industry policy, many straw pulp papermaking enterprises in the paper industry are in a dilemma. The national discharge standards for water pollutants in the papermaking industry are decreasing year by year, resulting in rising waste water treatment costs for papermaking enterprises, and it is often difficult to meet the discharge standards. Many enterprises are struggling to find a process method that does not discharge papermaking wastewater, and they are still in the exploration stage. [0003] The existing technology similar to the present invention is that Tianjin Wanli Natural Fiber Film Co., Ltd. uses waste paper to produce corrugated base paper to realize water recycling technology, but its waste water circulation is limited to a certain ext...

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Problems solved by technology

[0003] The existing technology similar to the present invention is that Tianjin Wanli Natural Fiber Film Co., Ltd. uses waste paper to produce corrugated base paper to realize water recycling technology, but its waste water circulation is limited to a certain extent, and its annual output does not exceed 100,000 tons, and its After the waste water is recycled, it has a serious impact on the product quality, making its product quality in the qualified grade in the GB / T13023-2008 standard, which is difficult to improve