A catalytic oxidation treatment method for 3,3'-dichlorobenzidine hydrochloride neutralized wastewater

Abstract

The invention discloses a catalytic oxidation treatment method used for neutralization of wastewater with 3,3'-dichlorobenzidine dihydrochloride. The catalytic oxidation treatment method comprises following steps: 1, mixing and suction filtration, wherein waste alkali is added into wastewater for neutralization until the acid-base property of wastewater is adjusted to be weak acidity, and suctionfiltration is carried out so as to obtain a clarified solution; 2, catalytic oxidation, wherein an active carbon catalyst is introduced into a catalytic oxidation reactor, tap water, distilled water,or deionized water is added, a filtrate obtained in step 1 is mixed with tap water, distilled water, or deionized water at a certain ratio, an obtained mixture is pumped to the top of the catalytic oxidation reactor continuously so as to realize oxidation reaction at normal temperature, a part of oxidation wastewater obtained via reaction is recycled, is mixed with the filtrate at a certain ratio,and an obtained mixed solution is subjected to oxidation reaction in the catalytic oxidation reactor, and the left oxidation wastewater is subjected to biochemical treatment. The catalytic oxidationtreatment method is capable of destroying the structure of organic matters in wastewater effectively, and converting large molecular organic matters into small molecular organic matters with low biochemical influence, so that wastewater biochemical treatment is realized. The catalytic oxidation reaction is carried out at normal temperature, energy consumption is low; the technical process is simple; and the industrialization prospect is promising.

Description

Technical field [0001] The invention relates to a method for catalytic oxidation treatment of 3,3'-dichlorobenzidine hydrochloride neutralizing wastewater, and belongs to the field of chemical treatment and chemical technology. Background technique [0002] 3,3'-Dichlorobenzidine, abbreviated as DCB, is an important intermediate for the production of dichlorobenzidine series organic pigments. The series of organic pigments mainly manufactured with it account for about 25% of the total organic pigments and are widely used Production of ink, paint, rubber, plastic, etc. coloring and pigment printing slurry, coating dyeing slurry. Its products generally exist in the form of hydrochloride, and the structural formula is: [0003] [0004] The production of 3,3’-dichlorobenzidine hydrochloride is based on o-nitrochlorobenzene, which is reduced in an alkaline medium to produce 2,2 ’ -Dichlorohydroazobenzene (DHB), then 2,2 ’ -Dichlorohydroazobenzene is translocated in acid medium to obta...

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Problems solved by technology

However, when waste acid is used mechanically, by-product organic matter will gradually accumulate, thereby affecting product quality

Patent CN 1752032A, industrial wastewater 3,3-dichlorobenzidine hydrochloride produces mixed acid treatment and recovery process, using magnesium-containing ore to react with sulfuric acid to reduce the acidity of wastewater and extract magnesium sulfate at the same time, but this method cannot effectively reduce Organic matter content in wastewater; patent CN 101372381A, a method and device for resourceful treatment of 3,3'-dichlorobenzidine hydrochloride wastewater, through evaporation, rectification, decolorization, filtration, cooling, crystallization, separation and other steps Treat the wastewater, recover the hydrochloric acid and sulfuric acid, and obtain the by-product of o-chloroaniline sulfate

However, the process of this method is complicated, and the evaporation, rectification and other units all have large energy consumption. From the perspective of economy, its industrial application is more difficult.

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