Method for performing Fenton treatment on 6-nitro-1-diazo-2-naphthol-4-sulfonic acid wastewater and coproducing sodium sulfate

Abstract

The invention discloses a method for performing Fenton treatment on 6-nitro-1-diazo-2-naphthol-4-sulfonic acid wastewater and coproducing sodium sulfate, which comprises the following steps: (1) adding alkali into 6-nitro-1-diazo-2-naphthol-4-sulfonic acid wastewater, and regulating the pH value to 2.0-3.0; (2) under stirring conditions, adding activated carbon, FeSO4 and H2O2 into the wastewater subjected to pH value regulation to perform oxidation reaction; (3) adding alkali into the oxidated wastewater to regulate the pH value to 9-10; (4) adding an Al2(SO4)3 solution into the wastewater treated by the step (3) until the pH value of the reaction system reaches 6-7, sufficiently standing and settling to obtain a turbid solution, and filtering the turbid solution to obtain a filtrate; (5) if the filtrate obtained in the step (4) satisfies the treatment requirements, concentrating by evaporation and drying to obtain the industrial-grade sodium sulfate; and if the filtrate obtained in the step (4) does not satisfy the treatment requirements, repeating the steps (2)-(4) until the filtrate satisfies the treatment requirements. The treatment method has the advantages of simple technique and no environment pollution, and can coproduce sodium sulfate in the treatment process, thereby maximally utilizing the resources.

Description

technical field [0001] The invention belongs to the technical field of industrial waste water treatment and reuse for environmental protection, and specifically relates to the comprehensive treatment of waste water produced in the production process of 6-nitro-1,2,4-acid oxygen body, and the co-production of sodium sulfate at the same time, which belongs to the category of clean production . Background technique [0002] 6-nitro-1,2,4-acid oxygen body, CAS number is 5366-84-7, the structure is shown in formula (I), the Chinese alias is 6-nitro-1-diazo-2-naphthol -4-sulfonic acid is an important dye intermediate, mainly used in the manufacture of acid dyes and metal complex dyes. [0003] [0004] The production method of 6-nitro-1,2,4-acid oxygen body is to use ethyl naphthol as the main raw material, and it is prepared through nitrosation, sulfonation, reductive transposition, diazotization, acid precipitation, nitration and other processes. There are three main source...

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Problems solved by technology

[0005] At present, there are two main methods for treating this type of wastewater: (1) complex extraction method, complex extraction treatment has high efficiency and high selectivity. The efficiency is reduced, and the stripping solution is difficult to handle at the same time

(2) Traditional Fenton treatment method, the traditional Fenton oxidation technology mainly uses lime to neutralize excess acid, produces calcium sulfate and other precipitates, and adsorbs and removes organic matter. Although it can achieve a decolorization rate>90%, the organic matter removal rate is relatively low. Low (COD removal rate is about 60%-70%), and H 2 o 2 The low utilization rate leads to high treatment costs. Due to incomplete oxidation, the final effluent is brownish-yellow to brown. It is difficult to discharge the wastewater up to the standard, and it is even more difficult to meet the reuse requirements. It also produces a large amount of solid waste, which increases the production cost of the enterprise and has an impact on the environment.

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