Medicament and process for treating and utilizing papermaking wastewater and waste residues

Abstract

The invention relates to a medicament and a process for treating and utilizing black liquor, white liquor and residues generated in a papermaking process, which are mainly completed by the following medicament adding and process: firstly, adding a medicament A into papermaking black liquor, stirring, filtering, recording filtered residues as precipitates (X1), recording filtrate as Y1, reusing the filtrate Y1 in an alkali boiling process for 5-10 times, then adding the medicament A again, and separating precipitates (X2) and filtrate Y2, adding a modifier B into the filtrate Y2 to layer the filtrate Y2, collecting an upper-layer crude product (Z1), distilling to obtain a fatty acid product (Z2), a lower-layer filtrate Y3 and distillation residues X3, combining the lower-layer filtrate Y3 with the white liquid, adding a heavy metal settling aid C, separating to remove harmful heavy metals, filtering, enabling filter residues containing heavy metals (X4) and the filtrate Y4, treating the filtrate Y4 wastewater in an ozone-photocatalysis D-biochemical system E to generate waste residues (X5), and recycling the waste residues (X5). The method comprises the following steps: adding a black liquor precipitate (X1 + X2), distillation residue (X3) and filter residue and waste residue (X5) into a black liquor precipitate (X1 + X2), combining the black liquor precipitate (X1 + X2), distillation residue (X3) and filter residue and waste residue (X5) into F residue, adding a modifier G into the F residue, fermenting, curing, then using the F residue as a plant nutrient, and finally discharging or partially recycling the wastewater after the wastewater reaches the standard.

Description

technical field [0001] The invention relates to a medicament and a process for treating black liquor, white liquor and waste residue produced in a papermaking process, and belongs to the field of waste water treatment and environmental protection. Background technique [0002] With the development of the papermaking industry, the pollution of papermaking waste is becoming more and more serious, among which the disposal of papermaking sludge and waste residue is an unavoidable problem, and the waste water produced by the waste pulping process in the papermaking industry contains a large amount of lignin black liquor, black liquor Contains a large amount of suspended solid organic matter, fatty acid, etc., directly discharged into the water body will cause serious pollution. [0003] The traditional methods of treating papermaking waste and sludge are mainly stacking, landfilling, incineration, etc., but the above methods all require expensive transportation costs, in addition...

AI Technical Summary

Problems solved by technology

[0002] With the development of the papermaking industry, the pollution of papermaking waste is becoming more and more serious, among which the disposal of papermaking sludge and waste residue is an unavoidable problem, and the waste water produced by the waste pulping process in the papermaking industry contains a large amount of lignin black liquor, black liquor Contains a large amount of suspended solid organic matter, fatty acid, etc., which will cause serious pollution if discharged directly into the water body

[0003] The traditional methods of treating papermaking waste and sludge are mainly stacking, landfilling, incineration, etc., but the above methods all require expensive transportation costs, in addition, they need to occupy a large amount of land, destroy the ecological balance, pollute the environment and groundwater; the traditional treatment of papermaking Black liquor methods include alkali recovery method, flocculation sedimentation method, acid analysis method, activated sludge method, etc.

Among them, the alkali recovery method is the most mature treatment method for papermaking black liquor at the present stage, but due to its high cost and low black liquor recovery efficiency, fatty acid substances are not recycled; the flocculation sedimentation method needs to add a large amount of precipitant Heavy metal components make the tailings lose their use value and increase resource input; the activated sludge method uses biological methods to treat black liquor, but the sludge cultivation time is long, it is not resistant to high-pressure water, and it takes a long time, which is not conducive to large-scale continuous operations. Based on the above Difficult. At present, most papermaking enterprises carry out three-effect-five-effect evaporation and concentration of cooking black liquor, incineration treatment, consume a large amount of natural gas and other resources, and waste residue to landfill, waste resources, and still have high processing costs and environmental pollution.

Images