JP2013081882A - Method for treatment of waste liquid discharged in manufacturing tnt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treatment of a red water waste liquid in which the waste water discharged in a TNT manufacturing process is treated to a level enabling a biological treatment.SOLUTION: The method includes: adjusting pH of the red water waste liquid discharged with TNT manufacture; and executing oxidation treatment by adding a ferrous sulfate heptahydrate of a catalyst, a copper sulfate pentahydrate of a promoter, a hydrogen peroxide, and a defoaming agent. Then, a caustic soda is added to an oxidation treatment water, and the catalyst is separated into solid and liquid by a filter, and thereafter is diluted with a raw water or water in a wastewater treatment plant.

Description

  The present invention relates to a treatment method for treating a waste liquid which is discarded in a TNT production process and contains an organic substance to a level at which it can be biologically treated.

  TNT, which is widely used as the main component of explosives such as shells, is produced by two-stage nitrification of 0 nitrotoluene (0NT) using a mixed acid of nitric acid and sulfuric acid. TNT) is also generated. The most common purification method of TNT is a celite method using an aqueous sodium sulfite solution. By adding an aqueous sodium sulfite solution, the reactive nitro group of the asymmetric TNT is replaced with sodium sulfonate. Therefore, it is easily removed by the celite method.

  This waste liquid has a unique red color (hereinafter, this waste liquid is referred to as red water waste liquid), has a large amount of organic matter and nitrate nitrogen, and has a very high COD (chemical oxygen demand). , A dilution of 100 times or more is necessary, which is expensive and impractical. Therefore, conventionally, the combustion process is performed using heavy oil as fuel.

Combustion treatment by heavy oil is not an optimal treatment method to generate CO ₂ with a greenhouse effect.
An object of this invention is to provide the processing method of the red water waste liquid which processes the waste liquid discharged | emitted in a TNT manufacturing process to the level which can be biologically processed.

The invention according to claim 1 is characterized in that a catalyst composed of a compound containing iron and a compound containing copper is added to a red water waste liquid discharged along with the production of TNT, and then an oxidation treatment is performed by adding hydrogen peroxide.
The invention according to claim 2 is characterized in that, in the invention according to claim 1, an antifoaming agent is added before hydrogen peroxide is added.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, after the oxidation treatment, the catalyst is removed and then diluted with raw water or water treated in a wastewater treatment plant.

  According to the first aspect of the invention, by adding a catalyst and hydrogen peroxide to the waste liquid discharged during the production of TNT and oxidizing the solution, the COD (chemical oxygen demand) of the solution is reduced, and biological treatment is reduced. It becomes possible.

  When hydrogen peroxide is added, foaming becomes intense, so a large treatment tank is required for red water treatment. In this regard, as in the invention according to claim 2, if an antifoaming agent is added, foaming can be suppressed and red water treatment can be performed even in a smaller treatment tank.

  As in the invention according to claim 3, biological treatment can be performed more reliably by removing and diluting the catalyst after the oxidation treatment.

The flowchart which shows embodiment. The flowchart which shows an Example.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
Red water waste discharged with TNT production is adjusted to pH in the oxidation treatment tank, and then the compound containing ferrous sulfate heptahydrate FeSO ₄ · 7H ₂ O, which is a compound containing iron as catalyst, and copper as the promoter Then, copper sulfate pentahydrate CuSO ₄ · 5H ₂ O is added, and hydrogen peroxide H ₂ O ₂ and an antifoaming agent are further added for oxidation treatment. Here, either the catalyst or the cocatalyst may be added before or after, but hydrogen peroxide is added simultaneously with or after the addition of the catalyst and the cocatalyst, and the antifoaming agent is added prior to the hydrogen peroxide. . As an antifoaming agent, for example, Ordeform FC-131, 120, 100 (trade name) manufactured by Organo Corporation, Cleides S-115 (trade name) manufactured by Kurita Kogyo Co., Ltd., or the like can be used.

  Then, it moves to the catalyst removal equipment provided with the filter, and caustic soda NaOH is added. Thereby, a catalyst precipitates as a hydroxide and is separated and removed by a filter. The oxidized water from which the catalyst has been removed is neutralized and then diluted with raw water or mountain water used in a wastewater treatment plant such as a sewage treatment plant.

In Fig. 2, sulfuric acid is added to waste liquid 140L having the physical properties shown in Table 1 below, which is discharged along with the production of TNT, and the pH is adjusted. Then, Ordeform FC-120 (trade name) 28g manufactured by Organo Corporation, FeSO 585 g of ₄ · 7H ₂ O and 150 g of CuSO ₄ · 5H ₂ O were added, and then 35.6 g of 35% hydrogen peroxide water H ₂ O ₂ was added to cause an oxidation reaction at 85 ± 5 ° C. Then, this was filtered with a filter, solid-liquid separation was performed, and the solid content was discarded. On the other hand, pH was adjusted by adding caustic soda NaOH to the filtrate, and then this was filtered with a filter to perform solid-liquid separation. . While discarding the solid content, the filtrate is neutralized by adjusting the pH with sulfuric acid, and 1722 L of raw organo water to be treated in the wastewater treatment plant made by Organo Corporation is added to the neutralized treated water to dilute it 10 times. did. Tables 2 and 3 below show the target values and measured values of treated water, the quality of treated water after dilution, and the Seto Law (Special Measures Law for Seto Inland Sea Environmental Conservation) drainage standards.

In Table 2, treated water after 10-fold dilution represents treated water obtained by diluting neutralized treated water 10-fold, and nitrogen content 270 → 14 in the treated water is 10-fold diluted nitrogen content in treated water Although it was 270 mg / L, it showed that it decreased to 14 mg / L as a result of the microorganism treatment by Organo Kansai Co., Ltd.
As shown in Table 2, the treated water after 10-fold dilution has cleared the permitted value of the Seto Law drainage standard.

Claims (3)

  A waste liquid discharged from TNT production, characterized by adding a catalyst comprising a compound containing iron and a compound containing copper to red water drained from the production of TNT, followed by oxidation by adding hydrogen peroxide. Processing method.   2. The method for treating a waste liquid discharged in TNT production according to claim 1, wherein an antifoaming agent is added before hydrogen peroxide is added.   The method for treating waste liquid discharged in TNT production according to claim 1 or 2, wherein after the oxidation treatment, the catalyst is removed and then diluted with raw water or water treated in a wastewater treatment plant.