Supplementary decoloration process for dye-containing waste water

Abstract

The invention discloses a supplementing decoloring technique of waste water with dye, which comprises the following steps: reserving alkali solution and acid solution of sodium dithionite in the seal container separately; blending the waste water with dye and alkali solution of sodium dithionite under high-speed stirring condition; leading the acid solution to neutrallize the waste water with dye; supplementing the decoloring; bubbling the decolored water through aerating pipe; oxidizing the excessive reduced material; placing the seal container and aerating pipe in the water outlet canal of waste water with dye. The invention reduces cost without changing the present equipment, which is benefit to recycle the waste water directly.

Description

technical field [0001] The invention relates to a supplementary decolorization process for dye-containing wastewater. Background technique [0002] Dyestuffs and dye intermediate production plants, bleaching and dyeing industry is a light industry in a pillar position in our country. Textile printing and dyeing wastewater has a large amount of water, high chroma, and complex components. The wastewater contains dyes, sizing, auxiliaries, acids, alkalis, fiber impurities, and inorganic salts. Common decolorization methods include biochemical decolorization (lowest cost, but cannot decolorize biologically toxic dyes), oxidative decolorization (better effect, slower decolorization speed), reductive decolorization (for biologically toxic dyes such as unsaturated bonds, Aldehyde dyes have a particularly good decolorization effect). At present, most printing and dyeing factories adopt biochemical treatment methods, that is, the use of microbial methods to degrade conventional dye...

AI Technical Summary

Problems solved by technology

[0003] The existing decolorization process has high treatment costs and slow reaction speed, so additional treatment equipment and places are required, and the investment cost is relatively high; and the residual substances such as hypochlorite and iron ions after treatment seriously interfere with the wastewater reuse effect

Some foreign companies use NaBH 4 The reduction method is used to decolorize wastewater in affiliated sites, the effect is very good and the wastewater can be reused after decolorization, but NaBH 4 The price is expensive (the price is about 180 yuan / kg), and it cannot be promoted

Common cheap and strong reducing substances such as Diaobai powder are highly toxic, and the general aqueous solution of sodium dithionite is extremely unstable, so they have not been used in the decolorization of dye-containing wastewater.

In addition, the problem of excess drug removal during reductive decolorization in practical applications has not yet been resolved.