Deep treatment method of pulping paper making wastewater

Abstract

The invention discloses a deep treatment method of pulping paper making wastewater. The method comprises the following steps that (1) a system is built; (2) a plurality of wastewater samples are taken; a coagulant, PAM and powdery active carbon are added; a solution is prepared; (3) the wastewater enters a coagulating pool; mixing and stirring are performed; (4) the wastewater enters a reaction pool for forming alumen ustum; the alumen ustum flows into an inclined plate sedimentation pool; a flocculating body is intercepted on an inclined plate; then, precipitates enter a mud collecting pool;a mud backflow pump is used for lifting; most wastewater is reused to the flocculation pool; little wastewater is outwards discharged; the outward discharging quantity can be regulated according to the COD value of outlet water; (5) after being clarified, the wastewater enters a filtering pool for filtering; collection is performed in a clear water pool. By flocculation, adsorption, precipitationand filtering methods, the pulping paper making wastewater is deeply treated; the outlet water quality is enabled to meet higher discharging requirements; the investment and operation cost is reduced;favorable conditions are created for reusing the wastewater in further.

Description

technical field [0001] The invention relates to a method for advanced treatment of pulping and papermaking wastewater, belonging to the technical field of papermaking. Background technique [0002] The pulp and paper industry has always had the problems of high water consumption and high pollution in all industries, and its wastewater treatment discharge is generally required to meet the requirements of "Table 2" in the "Water Pollutant Discharge Standards for the Pulp and Paper Industry (GB3544-2008) , some areas are required to meet the "Table 3 Special Discharge Limits of Water Pollutants" or even higher requirements. After the wastewater is biochemically treated, the COD concentration in the wastewater is relatively high, the BOD concentration is low, and the chroma is high. The industry generally adopts Fenton-type advanced oxidation treatment technology for advanced treatment to meet the requirements of wastewater discharge standards. [0003] Fenton oxidation technol...

AI Technical Summary

Problems solved by technology

Since Fenton’s reagent is mainly a chemical method, it oxidizes soluble and macromolecular COD, and the removal rate of oxidized small molecule COD is not high, which cannot effectively ensure that the effluent discharges up to the standard

[0006] (2) Uneconomical

Fenton oxidation technology generally has the problems of large area, large investment cost and high operating cost during operation

[0007] (3) Not environmentally friendly

① Although Fenton’s reagent removes organic matter in water, a large amount of substances dissolve into the water after the reaction, resulting in an increase in the conductivity of the effluent and total dissolved solids (TDS), which is not conducive to the subsequent use of ultrafiltration membranes and reverse osmosis membranes. Wastewater is reused, and new pollutants are added to the water body

② After the reaction of Fenton’s reagent, iron sludge is mainly precipitated. These iron sludges are difficult to dehydrate later, resulting in high moisture content of dehydrated sludge

At the same time, after the dehydrated sludge is blended into the thermoelectric boiler, the iron salt appears reddish brown, forming a color difference with the original slag, which affects the resource utilization of the subsequent slag

[0008] (4) Unsafe

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