Straw pulping paper-making or sulfite method pulping paper-making middle piece waste water treatment technique

Abstract

The invention discloses a technology for processing wastewater in middle section of wheat straw cleaning pulping papermaking or sulfite process pulping papermaking. The technology carries out pretreatment to the wastewater of the middle section of the pulping papermaking, which comprises the processes: precipitant with calcium is selected and added in the wastewater of the middle section before the wastewater of the middle section is biochemistry processed; firstly, sulfite ion in the wastewater is removed so that the content of the sulfite ion in the wastewater is reduced; then the biochemistry processing is carried out. The technology for processing wastewater in middle section of wheat straw cleaning pulping papermaking or sulfite process pulping papermaking is economically feasible, uses waste to control waste, is suiting for national environmental policy and has a good application value for popularizing.

Description

technical field [0001] The invention relates to a pulping and papermaking wastewater treatment process, in particular to a wheat straw clean pulping and papermaking process or a sulfite process pulping and papermaking mid-stage wastewater treatment process. Background technique [0002] Sulfite pulping and papermaking is a method commonly used in the paper industry. At present, a considerable number of domestic paper mills that use grass as raw materials are still using it. The mid-stage wastewater produced by this method contains a considerable amount of sulfite ions, and sulfite ions inhibit the activity of bacteria, which not only reduces the efficiency of biochemical treatment, but even makes biochemical reactions impossible, and the activated sludge disintegrates, affecting the biochemical treatment of wastewater. ; At the same time, sulfite ion consumes oxygen, and the oxygen consumption per kilogram is 0.2kg, and the following reactions take place: 2SO 3 2- +O 2 →2...

AI Technical Summary

Problems solved by technology

The mid-stage wastewater produced by this method contains a considerable amount of sulfite ions, and sulfite ions inhibit the activity of bacteria, which not only reduces the efficiency of biochemical treatment, but even makes biochemical reactions impossible, and the activated sludge disintegrates, affecting the biochemical treatment of wastewater. ; At the same time, sulfite ion consumes oxygen, and the oxygen consumption per kilogram is 0.2kg, and the following reactions take place: 2SO 3 2- +O 2 →2SO 4 2- As a result, the chemical oxygen consumption of the treated external drainage is relatively high, which is difficult to meet the requirements of the national standard "Discharge Standard of Water Pollutants for Paper Industry GB3544-2001"

According to the requirements of the national standard "Water Pollutant Discharge Standard for Paper Industry GB3544-2001": the main pollution factor of external drainage - chemical oxygen demand (CODcr) is less than 400mg / L, which is difficult to meet the growing environmental protection requirements of building an environmentally friendly society. high requirements