Method for treating acidic dye printing and dyeing wastewater

Abstract

The invention discloses a method for treating acidic dye printing and dyeing wastewater, which belongs to the field of wastewater treatment. The method comprises the steps of (1) filtering collected acidic printing and dyeing wastewater through a screen, then enabling the acidic printing and dyeing wastewater to enter a regulation tank, and using alkali waste to regulate the pH value of the acidic printing and dyeing wastewater to be 6.0-8.0; (2) feeding anionic surfactants into the regulation tank, and performing aeration decoloring treatment through a micro-nano aeration device; (3) enabling wastewater after aeration decoloring treatment to flowing through a sepiolite device of immobilized catalysts from bottom to top, wherein chemical oxygen demand (COD) in processed outlet water is lower than 100mg/L, the chromaticity is lower than 40mg/L, and the COD and the chromaticity both reach level 1 emission standards in Discharge standard of water pollutant for dyeing and finishing of textile industry. By means of combination of the anionic surfactants and the micro-nano aeration device, the method performs the aeration decoloring treatment on the acidic dye printing and dyeing wastewater, and absorption-catalysis is performed through the sepiolite device of the immobilized catalysts to further reduce the COD content in the wastewater. The method has the advantages of being simple in process flow, small in floor area, remarkable in effect of treatment on the COD and the chromaticity in the acidic dye printing and dyeing wastewater, and the like.

Description

technical field [0001] The invention discloses a method for treating acid dye printing and dyeing wastewater, which belongs to the technical field of sewage treatment in environmental protection. Background technique [0002] Traditional acid dyes refer to water-soluble dyes containing acid groups, and most of the acid groups contained on the dye molecule are in the form of sulfonic acid sodium salt, and only a few species are in the form of carboxylic acid sodium salt. Early dyes of this type were dyed under acidic conditions, so they were commonly called acid dyes. Acid dyes have the characteristics of complete chromatograms and bright colors. They are mainly used for dyeing and printing wool, silk and other protein fibers and polyamide fibers. They can also be used for coloring leather, paper, cosmetics and inks. Lake pigments. Acid dye wastewater has complex components, high salt content, high concentration of organic pollutants, deep color, large water quality changes...

AI Technical Summary

Problems solved by technology

Among them, the chemical method includes coagulation method, chemical oxidation method, electrochemical method, etc., which have a good removal effect on COD and a high decolorization rate on hydrophobic dyes; however, the decolorization effect on hydrophilic dyes is poor, and the treatment cost is high. Difficult to deal with, in addition, this method is not suitable for the treatment of large flow, and the removal effect of coagulation method on COD is poor; physical and chemical methods include adsorption decolorization, coagulation precipitation, ozone, chlorine bleaching and other chemical oxidation methods, ion exchange, ultrafiltration membrane Decolorization photocatalysis, high-voltage pulse electrolysis, etc., have remarkable treatment effects, but the treatment costs are high, the scope of application is narrow, and a large amount of difficult-to-treat sludge is likely to be produced; biochemical methods use the metabolism of microorganisms to decompose organic matter in wastewater. The leading process of printing and dyeing wastewater treatment, which can deal with a large amount of soluble substances contained in printing and dyeing industrial wastewater that can be oxidized by biology, mainly including aerobic method and anaerobic method

Among the biochemical methods, the biological contact oxidation method is a new type of wastewater treatment method developed in recent years. It has received extensive attention in the treatment of printing and dyeing industrial wastewater, and industrialized production devices have appeared. The main feature of this device is high treatment efficiency. The volume load can reach 1.5 kg / (m·d)~3 kg / (m·d), the residence time is short, the floor area is small, the biomass is large (and there are many types), and it can also remove biodegradable substances. At the same time, it can be used for tertiary treatment and denitrification, but its main disadvantages are: the filler is easy to block, and it needs to be washed frequently. When treating printing and dyeing wastewater, the ratio of air to water is high, about 1.15~1.25, and the power consumption is large. Under normal circumstances, about 0.4~0.5 kWh of electricity is needed to treat 1 ton of wastewater, which is higher than the activated sludge method

Therefore, the above methods generally have some disadvantages such as complex process flow, large floor space, high cost, low chroma removal rate, large fluctuations in treatment effect or failure to achieve the desired effect.