Condensation mother liquid waste water pretreatment and resource system and method in compound neutralization reactor in disperse blue 56 production process

Abstract

The invention discloses condensation mother liquid waste water pretreatment and a resource system and a method in a compound neutralization reactor in a disperse blue 56 production process, which belongs to the waste water treatment field. The method comprises the following steps: highly basic condensation mother liquid waste water in the disperse blue 56 production process and a mixed acid solution (sulfuric acid and sulfamic acid) in the compound neutralization reactor are neutralized, three purposes of reducing the pH value of waste water, precipitating phenol and removing nitrite can be simultaneously realized; the neutralized waste water passes through a fixed bed adsorption column filled with adsorption resin, so that residual phenol in the waste water can absorb on the resin column. Resin after adsorption saturation is carried out with desorption and regeneration by using a NaOH solution and then the resin is repeatedly usable, and the desorption liquid passes through the processes of acidity adjusting and vacuum distillation of phenol to realize recycling of phenol. According to the condensation mother liquid waste water which is pretreated in the disperse blue 56 production process, CODCr value is decreased from about 55000mg / L to less than 500mg / L, the phenols substance concentration is decreased from about 19000mg / L to less than 20mg / L, the nitrite ion is decreased from 87000mg / L to less than 20mg / L; thereby the treatment and resource utilization of waste water can be effectively realized.

Description

technical field [0001] The present invention relates to a pretreatment and recycling of wastewater in the production process of Disperse Blue 56, in particular to a compound neutralization reactor and a system and method for pretreatment and resource recovery of condensation mother liquid wastewater in the production process of Disperse Blue 56. Background technique [0002] Disperse Blue 56 (Disperse Blue56, CAS No.: 12217-79-7, also referred to as 56# blue) is an important dye, which will emit a large amount of highly concentrated phenol and sodium nitrite in the production process. Wastewater, Wastewater COD Cr About 55000mg / L, phenol content about 1.9% (mass fraction), nitrite ion content about 8.7% (mass fraction), pH>14, so the wastewater has high toxicity and poor biodegradability, and it is difficult for subsequent treatment. Effective governance can wreak havoc on the environment. There are three technical problems to be solved in the treatment process of the w...

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Problems solved by technology

[0003] Difficulties 1. Strong alkalinity in wastewater: The condensation mother liquid wastewater in the production process of Disperse Blue 56 is strongly alkaline and contains 8.7% nitrite ions. If the acid drops are added to the wastewater to neutralize the alkalinity by conventional methods, there will be A large amount of highly irritating nitric oxide and nitrogen dioxide gas escapes, which not only pollutes the air, but also seriously endangers the health of operators;

[0004] Difficulty 2. Wastewater contains high concentration of sodium phenate: the condensation mother liquid wastewater in the production process of Disperse Blue 56 is strongly alkaline, and phenol exists in the form of sodium phenate in the wastewater. It is difficult to remove sodium phenate in alkaline aqueous solution by traditional resin adsorption method;

[0005] Difficulty 3. Wastewater contains a large amount of nitrite ions: the biological toxicity is high, and it is easy to become an important source of water eutrophication factor "nitrogen"

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