Method for processing wash water in stock preparation by straw pulp wet method

Abstract

The invention discloses a method for treating scouring water of stock preparation by a straw pulp wet method. The method comprises the following steps: (1) an inclined wire is used for filtration, and filtered water enters a buffer pool; (2) chemical reaction is performed, wherein the water in the buffer pool is sent to a catchment reaction pool by a lift pump, and a flocculating agent is added to a transfer piping in front of the lift pump; and (3) waste water after reaction enters a flotation tank for air floating through the lift pump, a polyacrylamide solution is added to an outlet of the lift pump, and the water after air floating treatment is drained to a trench or is recycled for wet stock preparation. Compared with the medium wastewater treatment, the method has simple process and equipment, can become a treatment unit independent of medium wastewater, and can flexibly adapt to the fluctuation of yield in production, not only meet production requirement, but also achieve the aim of environmental protection, thereby reducing load of treating the medium wastewater, reducing the sediment content in stewed black liquor, and reducing interference to an alkali reclaim system. The method has the advantages of good effect of water treatment and lower operation cost, and the treatment cost of 1 ton of water is between 0.5 and 2.3 Yuan.

Description

Technical field: [0001] The invention relates to a sewage treatment method, in particular to a treatment method for straw pulp wet preparation and washing water. Background technique: [0002] Pulping and papermaking wastewater has become the top priority in water treatment due to its large discharge and serious pollution. The improvement of pulping and papermaking technology and equipment, the treatment and comprehensive utilization of wastewater are closely related to the promotion of my country's ecological environment protection and the sustainable development of the paper industry, and are related to the completion of the emission reduction task of my country's main pollutants. At present, a large amount of washing wastewater (chemical oxygen demand CODcr content is 2000-5000mg / l, suspended solids SS content is 2000-4000mg / l) produced in the wet preparation of straw pulp is not treated, but is directly sent to the middle section deal with. Due to the limited treatment...

AI Technical Summary

Problems solved by technology

Due to the limited treatment capacity of the middle-stage wastewater, it will inevitably increase the treatment load of the middle-stage wastewater and affect the treatment effect of the wastewater. At the same time, it will increase the sediment content in the cooking black liquor and interfere with the alkali recovery system.