Preparation method of flocculent decolouring agent of printing and dying wastewater

Abstract

The invention discloses a preparation method of a flocculent decolouring agent of printing and dying wastewater. The method comprises the following steps: adding formaldehyde of 15-30 parts by weight to a reaction kettle, and then adding dicyandiamide of 20-40 parts by weight and ammonium chloride of 10-25 parts by weight thereto, heating the mixture for 1-2 hours at 50 DEG C to 60 DEG C, warming up to 70 DEG C to 80 DEG C to continuously react for 2-4h; cooling to 50 DEG C to 60 DEG C, adding urea of 0-5 parts by weight to the mixture to react for 2-4 hours to obtain a component A; mixing industrial waste alumina mud with hydrochloric acid, heating the mixture to 70 DEG C to 80 DEG C to react for 2-4 hours, and curing for 12-24 hours after cooling to obtain a component B. When in use, according to the specific ingredients of the printing and dying wastewater, the component A and the component B are mixed in a ratio of 2-3:1 and then added to the printing and dying wastewater. After the product is added to the wastewater, the effect on flocculation is good, the settling rate of dirt is rapid, the decolouring ratio is up to 95-99%, the COD (Chemical Oxygen Demand) is reduced by 80-90%, 90% of processed wastewater can be reused, and the processing cost is decreased evidently.

Description

technical field

[0001] The invention relates to a preparation method of a sewage treatment agent, in particular to a preparation method of a flocculation and decolorization agent for printing and dyeing wastewater. Background technique

[0002] Printing and dyeing wastewater contains a variety of dyes, pastes and inorganic additives, with complex components and difficult treatment.

[0003] At present, the printing and dyeing wastewater is generally pretreated first, and then treated by biochemical methods. In the pretreatment, the commonly used flocculation and decolorization agents are iron-based and aluminum-based, which have poor decolorization and flocculation effects, and may cause secondary pollution to the environment.

[0004] Dicyandiamide-formaldehyde polymer decolorizer and polyaluminum chloride flocculant act synergistically, and the decolorization and flocculation effects are better, but dicyandiamide-formaldehyde polymer is expensive, which leads to an increa...

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