CN1590311A

CN1590311A - Treatment method of hydrazin containing waste water

Info

Publication number: CN1590311A
Application number: CN 200310105864
Authority: CN
Inventors: 樊秉安; 任向红
Original assignee: External Technology Service Department No2 College Of Artillery Engineering
Current assignee: External Technology Service Department No2 College Of Artillery Engineering
Priority date: 2003-10-28
Filing date: 2003-10-28
Publication date: 2005-03-09

Abstract

A process for treating the hydrazine contained sewage features the reaction between said sewage and H2O2 under alkaline condition and existance of Cu(or Mn) salt as catalyst.

Description

Treatment method of hydrazine-containing wastewater

Technical Field

The invention belongs to the technical field of wastewater treatment, and relates to a treatment method of hydrazine-containing wastewater.

Background

The hydrazine comprises anhydrous hydrazine (N)₂H₄) And hydrazine hydrate (N)₂H₅OH) and hydrazine are mainly used as propellant of space rockets and missiles, have larger consumption in civil use and are widely used as boiler corrosion inhibitors (namely oxygen scavengers). Hydrazine belongs to a third-level moderate poison, has fat solubility, can enter human bodies through skin, respiratory tracts, digestive tracts and wounds to cause poisoning, and can cause pollution after being discharged to the environment, so that the discharge of hydrazine-containing wastewater has a very strict control standard, the maximum allowable concentration of hydrazine in domestic drinking water source water is 0.02mg/L (GB18061-2000), and the hydrazine-containing wastewater can be discharged after reaching the standard after being treated. CN1396126A provides a method for treating hydrazine-containing wastewater generated in azodicarbonamide production, which mainly adopts a pretreatment-biochemical method, has complex equipment and adopts the method for treating the wastewater with complex raw sewage componentsIn this way. For hydrazine-containing wastewater with single component, Japan has used air oxidation method to treat hydrazine-containing wastewater discharged from boiler in the presence of palladium catalyst, but the cost is higher because expensive palladium catalyst is used. The treatment method of the hydrazine-containing sewage in China mainly comprises a natural purification method, a chlorination method, an air oxidation method, an ozone oxidation method and a potassium permanganate oxidation method, wherein the natural purification method has a long treatment period; the chlorination method and the potassium permanganate oxidation method can generate strong carcinogen nitrosamines after oxidation; the ozone oxidation method needs an ozone generator, is expensive, and ozone cannot exist stably at normal temperature, so that the application of the ozone oxidation method is limited. Effective hydrazine catalysts are nickel-based catalysts, metals such as titanium, molybdenum, iron, platinum and palladium, and compounds thereof, and also hydrazine-containing wastewater is poured onto coal ash or slag, and hydrazine can be oxidized by oxygen in the air and an oxidizing agent (Fe) in ash₂O₃、SO₃) Oxidation, although an economical process, is very incomplete.

Disclosure of Invention

In view of the above prior art, the present invention aims to provide a novel method for treating hydrazine-containing wastewater by using a hydrogen peroxide/catalytic method, which is simple, convenient, easy to implement and relatively low in cost.

The hydrogen peroxide reacts with hydrazine to generate hydrazine salt (N)₂H₅OOH), which decomposes to diimide and is further oxidized by hydrogen peroxide to form nitrogen and water, according to the following reaction formula:

the invention relates to a method for treating hydrazine-containing wastewater by a reaction of producing hydrazine salt by reacting hydrogen peroxide with hydrazine and further oxidizing to produce nitrogen and water, wherein the hydrogen peroxide is an oxidant and is characterized in that: the reaction is carried out under the conditions of alkaline and catalyst; the molar ratio of hydrogen peroxide to hydrazine is 1-10: 1; the catalyst is copper ion or manganese ion; the adding amount of the catalyst is 1-20 mg/L; when copper ions are used as a catalyst, the pH value of the wastewater is adjusted to 9-11; when manganese ions are used as a catalyst, the pH value of the wastewater is adjusted to 10-12; the reaction temperature is controlled between 15 ℃ and 40 ℃; circularly stirring for 3-5 minutes; 1000mg/L of hydrazine-containing wastewater can be treated within 3-6 minutes to reach the sewage discharge standard.

Drawings

FIG. 1: themethod of the invention has a process flow diagram

Detailed Description

Example 1: (see the figure 1) in 1000mg/L hydrazine-containing waste water, adding 10mg copper ion as catalyst, and making anhydrous hydrazine N₂H₄Hydrogen peroxide solution H₂O₂The molar concentration ratio (mol/mol) of the hydrazine is 1: 1, the pH value is adjusted to 10, the reaction temperature is adjusted to 15 ℃, the cyclic stirring is carried out for 3 minutes, and after the reaction is carried out for 6 minutes, the residual concentration of the hydrazine in the wastewater is less than 0.1 ppm.

Example 2: (referring to figure 1), adding 10mg of manganese ions as a catalyst into 4000mg/L hydrazine wastewater, and adding anhydrous hydrazine N₂H₄Hydrogen peroxide solution H₂O₂Molar concentration ratio of N₂H₄/H₂O₂(mol/mol) is 2: 1, the pH value is adjusted to 10, the reaction temperature is adjusted to 29 ℃, the cyclic stirring is carried out for 3 minutes, and after the reaction is carried out for 3 minutes, the residual concentration of hydrazine in the wastewater is below 0.1 ppm.

The concrete operation process of the hydrazine-containing wastewater treatment example comprises the following steps:

(1) a water injection stage: the valve 1, the valve 7 and the pump are opened to fill the reactor with waste water, and the filling is finished when the filling reaches the upper limit of the liquid level.

(2) A catalytic oxidation stage: valve 2 is opened and base is added to the reactor to adjust to the optimum pH. The valves 3 and 4 are opened again to add the oxidant and catalyst to the reactor.

(3) And (3) stirring: valve 5 was opened, valve 1 was closed and stirring was cycled for 3 minutes.

(4) A drainage stage: if the detector detects N in the water₂H₄When the concentration was 0.1ppm, the valve 7 was closed, the valve 6 was opened, and waste water was discharged.

Compared with the prior art, the invention has the advantages that: the method for treating the hydrazine-containing wastewater has the advantages of high efficiency, high speed, no secondary pollution, convenient raw material source, low price and low treatment cost.

Claims

1. A treatment method of hydrazine-containing wastewater is characterized in that hydrazine-containing wastewater is treated by a reaction of generating hydrazine salt according to the reaction of hydrogen peroxide and hydrazine and further oxidizing to generate nitrogen and water, wherein the hydrogen peroxide is an oxidant and is characterized in that: the reaction is carried out under the conditions of alkaline and catalyst; the molar ratio of hydrogen peroxide to hydrazine is 1-10: 1; the catalyst is copper ion or manganese ion; the addition amount of the catalyst is 1-20 mg/L.

2. The method for treating hydrazine-containing wastewater according to claim 1, wherein: the reaction temperature is controlled between 15 ℃ and 40 ℃; and circularly stirring for 3-5 minutes.

3. The method for treating hydrazine-containing wastewater according to claim 1, wherein: when copper ions are used as a catalyst, the pH value of the wastewater is adjusted to 9-11; when manganese ions are used as a catalyst, the pH value of the wastewater is adjusted to 10-12;