CN107346670B

CN107346670B - Removing in high-salinity wastewater90Precipitation method of Sr

Info

Publication number: CN107346670B
Application number: CN201710456817.3A
Authority: CN
Inventors: 李玉松; 郑宇�; 张振涛
Original assignee: China Institute of Atomic of Energy
Current assignee: China Institute of Atomic of Energy
Priority date: 2017-06-16
Filing date: 2017-06-16
Publication date: 2020-10-09
Anticipated expiration: 2037-06-16
Also published as: CN107346670A

Abstract

The invention discloses a method for removing high-salinity wastewater⁹⁰A method for precipitation of Sr, comprising the steps of: (1) preparing a precipitation adsorbent, (2) adjusting the pH value of the high-salt wastewater, and (3) adding the precipitation adsorbent into the high-salt wastewater and stirring to formMixing the solution, (4) carrying out solid-liquid separation on the mixed solution in the step (3); wherein the prepared precipitation adsorbent is a solution containing positive tetravalent titanium ions. The invention provides a method for removing high-salinity wastewater with simple operation and good decontamination effect⁹⁰Sr precipitation method.

Description

Removing in high-salinity wastewater90Precipitation method of Sr

Technical Field

The invention relates to radiationThe field of sexual waste treatment and disposal, in particular to removal in high-salinity wastewater⁹⁰Sr precipitation method.

Background

In radioactive waste water, radioactivity⁹⁰Sr is an important component of nuclear fission products. After a nuclear reactor accident, they constitute one of the important factors that constitute a hazard to the human body. When radioactive strontium enters the human body and is mainly accumulated in bones, the accumulation of radioactive strontium is generally more rapid and rapid in young people than in adults, because the radioactive strontium is selectively accumulated mainly in areas where bone formation is active, i.e., areas where calcification is vigorous, after the intake of strontium in young people. The difference in accumulation occurs in the elderly after strontium intake because active osteogenesis no longer occurs in their bodies. In addition, radioactive strontium can cause damage to the hematopoietic system in vivo, and its long-term effects can be carcinogenic, such as leukemia. There are 17 isotopes of strontium. The most common of which is⁸⁹Sr and⁹⁰Sr，⁹⁰the half-life period of the Sr is 28.9 years,⁸⁹the Sr half-life is 50.4 days. Thus radioactive strontium, especially⁹⁰Sr removal must be highly appreciated by us.

At present, for containing⁹⁰Domestic and international treatment methods for Sr radioactive waste liquid generally include precipitation, solvent extraction, membrane and ion exchange methods. Compared with other methods, the precipitation method has the advantages of simple process operation, low cost and suitability for treating large-volume waste liquid, a lot of research works have been carried out at present, and the precipitation method for removing strontium is mentioned in the research progress of the strontium removal technology of high radioactive waste liquid published in volume 47, 6 th of 2013, namely, volume 47, namely atomic energy science and technology, but the traditional precipitation method only has the defects of low salt, complex steps, intermittent operation, poor safety and the like and is only used in the environment with the acidity of 1-2. Therefore, on the premise of not carrying out desalination treatment on the wastewater, the development of a salt-resistant and efficient precipitation adsorbent is necessary, and the development difficulty is very large.

Disclosure of Invention

Objects of the invention

Aiming at solving the problem that the prior precipitation method is not suitable for high-salinity wastewater⁹⁰Sr removal problem, the present invention providesRemoving in high-salinity wastewater⁹⁰Sr precipitation method.

(II) technical scheme

In order to solve the technical problems, the invention is realized by the following technical scheme:

removing in high-salinity wastewater⁹⁰A method for precipitation of Sr, comprising the steps of:

(1) preparing a precipitation adsorbent, (2) adjusting the pH value of the high-salt wastewater, (3) adding the precipitation adsorbent into the high-salt wastewater, and stirring to form a mixed solution, (4) carrying out solid-liquid separation on the mixed solution obtained in the step (3);

the key point is that the prepared precipitation adsorbent is a solution containing positive tetravalent titanium ions.

Further, the concentration of the precipitation adsorbent in the step (1) is 0.1-1.0mol/L, the pH value of the high-salt wastewater in the step (2) is adjusted to 7-13, and the titanium ion concentration of the mixed solution in the step (3) is 1-20 mmol/L.

Further, the concentration of the precipitation adsorbent in the step (1) is 0.32mol/L, the pH value of the high-salinity wastewater in the step (2) is 12, and the concentration of titanium ions in the mixed solution in the step (3) is 3.4 mmol/L.

(III) advantageous effects

The invention is carried out by precipitation method in high salt environment for the first time⁹⁰Sr removal and the use of a precipitation adsorbent containing positive tetravalent titanium ions, the hydrolysis product of the precipitation adsorbent has strong adaptability to high-salt environments (the salt content is more than 20g/L), is not interfered by other ions, and is used for removing Sr⁹⁰No flocculating agent is required to be added in the Sr process; hydrolysis and pairing of titanium ions⁹⁰Sr is removed simultaneously, the decontamination time is short, the continuous treatment can be realized, and the process condition requirement is not harsh, so the process has simple steps and easy control of conditions, and the Sr removal is carried out in high-salinity wastewater with the salinity of more than 20g/L⁹⁰The Sr removal effect is obvious.

Drawings

FIG. 1 Process flow diagram of the present invention

Detailed Description

(1) preparing a precipitation adsorbent containing positive tetravalent titanium ions with the concentration of 0.1-1.0mol/L, (2) adjusting the pH value of the high-salt wastewater to 7-13, (3) adding the precipitation adsorbent into the high-salt wastewater, stirring to form a mixed solution, adjusting the titanium ion concentration of the mixed solution to 1-20mmol/L, and (4) carrying out solid-liquid separation on the mixed solution in the step (3);

example 1

The implementation process adopts the steps, and the main process parameters are as follows:

(1) accurately weighing 24g of Ti (SO)₄)₂The solid was placed in a 1000mL volumetric flask and then Ti (SO) was added to deionized water₄)₂Dissolving completely, and obtaining 0.1mol/L Ti (SO) after constant volume₄)₂And (3) solution.

(2) And accurately preparing 10mol/L NaOH solution for adjusting the pH of the high-salt wastewater, and adjusting the pH of the high-salt wastewater to 11.

(3) Taking Ti (SO)₄)₂The solution (0.1mol/L) was added to 1L of the high-salt wastewater so that the titanium ion concentration was 1mmol/L, followed by rapid stirring.

(4) After 2min, the mixed solution is subjected to solid-liquid separation through a high-efficiency filter membrane of 0.22 mu m, liquid is collected to obtain purified water, and the purified water is sampled and analyzed.

The DF value was 214 as measured by radioactivity in purified water.

Example 2

The same procedure as used in example 1, except that in step (1), Ti (SO) was used₄)₂The solution concentration is 0.32mol/L, the PH value of the high-salinity wastewater is adjusted to 12 in the step (2), the titanium ion concentration in the mixed solution in the step (3) is 3.4mmol/L, and finally the DF value is measured to be 340.

Example 3

The same procedure as in example 1 was followed, except that in step (2), the pH of the high-salinity wastewater was adjusted to 7, and in step (3), Ti (SO) was added₄)₂The solution concentration is 1.0mol/L, Ti (SO) is added into 1L of high-salinity wastewater₄)₂The solution (1mol/L) was adjusted to a titanium ion concentration of 20mmol/L, and the DF value was finally determined to be 303.

Example 4

The same procedure as used in example 1 was followed, except that,

(1) preparing Ti (SO) with the concentration of 0.2mol/L₄)₂A solution;

(2) preparing NaOH solution with the concentration of 10 mol/L. Adding 10mol/L NaOH solution into a reaction tank containing high-salinity wastewater, and adjusting the pH value to 13.

The wastewater treatment capacity in this example was 100L/h. Wherein the components of the high-salinity wastewater are detailed in attached table 1 and attached table 2.

TABLE 1 attached salt composition of high-salinity wastewater

TABLE 2 attached table radioactive constituents of high-salt waste water

(3) Adding 0.2mol/L Ti (SO) into the reaction tank₄)₂And (3) solution.

(4) Solid mud is separated and removed through a high-speed centrifuge and a high-efficiency filter membrane, the generated Sr mud is collected by a mud tank, and purified water is collected by a purification tank.

By performing a radioactivity measurement on the purified water, it⁹⁰The Sr activity is 1.64 +/-0.30 Bq/L, and the DF value is 215.

Claims

1. Removing in high-salinity wastewater⁹⁰A method for precipitation of Sr, comprising the steps of:

it is characterized in that the prepared precipitation adsorbent is a solution containing positive tetravalent titanium ions; removal of hydrolysis products using positive tetravalent titanium ions⁹⁰Sr。

2. According toThe high salinity wastewater of claim 1 to remove⁹⁰The Sr precipitation method is characterized in that the concentration of the precipitation adsorbent in the step (1) is adjusted to 0.1-1.0mol/L, the pH value of the high-salt wastewater in the step (2) is adjusted to 7-13, and the titanium ion concentration of the mixed solution in the step (3) is adjusted to 1-20 mmol/L.

3. The high salinity wastewater removal system defined in claim 2⁹⁰The Sr precipitation method is characterized in that the concentration of the precipitation adsorbent in the step (1) is 0.32mol/L, the pH value of the high-salt wastewater in the step (2) is 12, and the titanium ion concentration of the mixed solution in the step (3) is 3.4 mmol/L.