Treatment process for wastewater in dyeing and finishing industry

Abstract

The invention relates to a treatment process for wastewater in a dyeing and finishing industry. The treatment process is characterized by comprising the following steps: a. carrying out grid treatment, namely carrying out the grid treatment on the wastewater containing various types of dispersible dyestuffs to remove large particulate matters; then conveying the wastewater into an adjusting tank 1; b. adjusting the pH (Potential of Hydrogen) value, namely adjusting the pH of the wastewater to be 3-5 with industrial hydrochloric acid and then conveying the wastewater into an adsorption tank; c. adsorbing by mushroom cultivation wastes, namely adding the crushed mushroom cultivation wastes into the adsorption tank in advance and depositing at a natural temperature for 1h-2h, wherein the chroma removal rate of the wastewater subjected to adsorption treatment reaches 97% and the removing rate of COD (Chemical Oxygen Demand) is 20%-35%; and d. treating by an aerobic activated sludge method, namely conveying deposited supernatant into an adjusting tank 2 and mixing the supernatant with textile alkali boiling wastewater until the pH value is 6-8; and pumping the wastewater into an aeration tank, and treating by utilizing the aerobic activated sludge method, wherein the hydraulic retention time is 12 hours.

Description

technical field [0001] The invention relates to a process for treating wastewater in the dyeing and finishing industry. Background technique [0002] The printing and dyeing industry has a large amount of wastewater, high content of organic waste, and deep color. Although the COD is high, the BOD / COD value is small and the biochemical properties are poor. It is recognized as one of the difficult-to-treat industrial wastewater. At present, there are several methods to deal with printing and dyeing wastewater. (1) Biological method: Biological treatment is widely used in the treatment of urban domestic sewage, but the direct treatment of printing and dyeing wastewater by biological method is greatly affected by the temperature, pH value, dye type, etc. of the wastewater, and it is easy to cause sludge swelling and polymer group disintegration etc., which leads to poor treatment effect, and the treated wastewater cannot be discharged up to the standard; and the high concentrat...

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Problems solved by technology

(1) Biological method: Biological treatment is widely used in the treatment of urban domestic sewage, but the direct treatment of printing and dyeing wastewater by biological method is greatly affected by the temperature, pH value, dye type, etc. of the wastewater, and it is easy to cause sludge swelling and disintegration of polymer groups etc., resulting in poor treatment effect, and the treated wastewater cannot be discharged up to standard; and printing and dyeing wastewater has high concentration and high toxicity, and direct treatment of wastewater will easily cause the death of bacteria in the sludge, resulting in the failure of wastewater treatment to meet the standard

(2) Physical adsorption method: activated carbon porous adsorption materials are commonly used to adsorb dyes and other substances. It is easily affected by the pH of wastewater, suspended solids in wastewater, polymer pollutants, grease, etc., and the consumption is large and the cost is high; The effect on chromaticity is more obvious, but the ability to remove COD is not strong

o 3 Oxidation method equipment cost is high, dosage is large, Cl 2 The oxidation method is highly toxic and causes secondary pollution; the flocculation method is widely used because of its low investment cost, small equipment footprint, large processing capacity, and high decolorization rate, but some dye wastewater cannot achieve the purpose of decolorization and COD removal by direct flocculation

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