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Process for treating and recycling wet finishing mixing wastewater in leather production

A technology of mixed wastewater and wet finishing, applied in the direction of water/sewage multi-stage treatment, water/sludge/sewage treatment, chemical instruments and methods, etc., can solve the problems of deep pit discharge, few in number, and abnormal operation , to achieve stable effluent quality, easy operation, and good sewage treatment and reuse effects

Active Publication Date: 2014-06-25
CHINA LEATHER & FOOTWEAR IND RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] At present, 95% of the existing sewage treatment facilities in the domestic tanning industry have reached the second-level discharge standard in the national "Comprehensive Wastewater Discharge Standard", reaching the first-level discharge standard, and there are not many in normal operation, mostly because The treatment process is unreasonable, the operating cost is too high, and the operation management is cumbersome, so it cannot run normally
In addition, a certain amount of wastewater from tanneries is directly discharged into rivers or lakes without treatment or after simple sedimentation, and some are even discharged into deep pits, which has caused great harm to the ecological environment and living environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment example 1

[0024] a. Collect the mixed wastewater from wet finishing into the mixing tank, add polyaluminum chloride (PAC) aqueous solution (10% concentration) with a volume ratio of 3% of wastewater to the mixed wastewater, and stir vigorously to make it fully mixed with the mixed wastewater Reaction; then add 3% polyacrylamide (PAM) aqueous solution by volume to the mixed wastewater, the concentration of the PAM aqueous solution is controlled at 3‰; after fully stirring, press filter the wastewater.

[0025] b, use sulfuric acid to adjust the pH of the filtrate to about 4, then add solid potassium permanganate (KMnO 4 ), before adding potassium permanganate, it needs to be made into a 10% solution, and then added to the pretreated supernatant, and then vigorously stirred for oxidation reaction for 1.5h.

[0026] c. After the oxidation reaction is completed, use Ca(OH) 2 Adjust the pH to about 10.0, and perform press filtration after vigorous stirring and reaction; collect the filtrate...

Embodiment example 2

[0029] a. Collect the mixed wastewater from wet finishing into the mixing tank, add ferric phosphate (PFP) aqueous solution (the concentration is 5%) with a volume ratio of 4% of the treated wastewater to the mixed wastewater, and stir vigorously to make it fully react with the mixed wastewater ; Then add 4% polyacrylamide (PAM) aqueous solution by volume to it, the concentration of PAM aqueous solution is controlled at 3‰;

[0030] b. Use sulfuric acid to adjust the pH of the filtrate to about 3.5, and then add potassium permanganate (KMnO 4 ), before adding to the pretreated supernatant, potassium permanganate needs to be made into a 10% solution, and after adding, vigorously stir for oxidation reaction for 1 h.

[0031] c. After the oxidation reaction is completed, use Ca(OH) 2 Adjust the pH to about 11.0, and after vigorously stirring and reacting, press filter the precipitate; collect the filtrate, add NaOH to it, further adjust the pH to above 14.0, and fully stir the r...

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PUM

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Abstract

The invention discloses a process for treating and recycling wet finishing mixing wastewater in leather production. The wet finishing mixing wastewater specifically comprises neutralizing wastewater, retanning filling wastewater, dyeing wastewater and ester adding mixing wastewater. The treatment method of the mixing wastewater comprises the following steps of: adding a coagulant and a coagulant to wastewater for flocculating and precipitating; filtering; adding acid to adjust pH until reaching a certain range; adding an oxidant for oxidizing; precipitating by the stage type precipitating method after the oxidization is finished; then adding acid to adjust the pH of the treated wastewater to be neutral; and finally recycling. According to the recycling process for treating the wet finishing mixing wastewater in the leather production, the technology in the combination of flocculating method and the oxidization method is utilized for removing the pollutant in the wastewater; in addition, the secondary precipitating method is carried out to further remove the pollutant in the wastewater, and as a result, the purposes of purifying water and recycling wastewater are reached.

Description

technical field [0001] The invention relates to a treatment and reuse process for leather industrial wastewater, and belongs to the field of sewage treatment and reuse. Background technique [0002] The tanning industry is a major producer of sewage. The tanning sewage not only has a large output, but also has complex components and high concentrations, among which COD Cr 、BOD 5 , sulfide, ammonia nitrogen, suspended solids, etc. are very high, and it is a kind of industrial wastewater that is difficult to treat. According to the specific requirements of raw leather and products, the leather production process is also different, so the wastewater composition in the production process is also quite different. The leather production process can be divided into preparation section, tanning section, wet finishing section, dry Finishing section. [0003] The preparation section mainly includes immersion, degreasing, liming and hair removal, deliming, and softening processes; t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04
Inventor 陈国栋丁志文陈永芳庞晓燕程正平刘娜杨雅琼
Owner CHINA LEATHER & FOOTWEAR IND RES INST