CN110668538A

CN110668538A - Preparation method of titanium polychloride

Info

Publication number: CN110668538A
Application number: CN201910892287.6A
Authority: CN
Inventors: 赵艳侠; 刘潇; 田昌; 许伟颖; 李蒴
Original assignee: University of Jinan
Current assignee: University of Jinan
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2020-01-10
Anticipated expiration: 2039-09-20
Also published as: CN110668538B

Abstract

The invention provides a preparation method of titanium polychlorid, which comprises the following steps: the titanium tetrachloride solution is reacted under the low-temperature hydrothermal condition of 50-80 ℃ to obtain the titanium tetrachloride. The method of the invention has no addition of other chemical reagents except the raw materials of the flocculant, is more economic and environment-friendly, has low cost, can be widely applied to the treatment of surface water and wastewater, and has the characteristics of simple process, less reagent consumption, economy and environmental protection, and the like. The invention provides a novel method for synthesizing a novel polymeric titanium salt flocculating agent, and has important significance for widening the application of the titanium salt flocculating agent in a water treatment process.

Description

Preparation method of titanium polychloride

Technical Field

The invention belongs to the technical field of sewage treatment, and particularly relates to a preparation method of a flocculating agent titanium polychloride.

Background

With the development and application of the novel high-efficiency coagulant, the coagulation can not only effectively remove suspended particulate matters and colloidal substances in the water body, but also has good removal effect on organic pollutants, algae substances, bacteria and the like in the water body.

In recent years, titanium salts have been used as oneThe novel water treatment agent is widely concerned and rapidly developed, and has obvious advantages compared with the traditional aluminum salt and iron salt coagulants. The titanium salt has better defluorination and decoloration effects, the generated floc is large, the sedimentation speed is high, the organic matter removal rate is high, the residual titanium content in the water body after coagulation is low, the biotoxicity is avoided, and the sludge generated by titanium salt coagulation can be used for preparing the nano TiO with the photocatalytic effect by methods such as high-temperature calcination and the like₂Materials and the like, and can not cause secondary pollution.

At present, titanium salt coagulants mainly used are titanium tetrachloride and polymeric titanium chloride. Titanium tetrachloride is not easy to store, and the pH value of the coagulation effluent is low; the titanium polychloride is mainly prepared by a slow alkali dropping method, but the synthesis speed of the slow alkali dropping method is slow, the consumed reagent is more, and the process is more complex. Therefore, optimizing the coagulation effect of titanium tetrachloride, simplifying the preparation steps of titanium polychloride and reducing the dosage of reagents, and finding a coagulant which has good treatment effect, simpler preparation method and environmental protection is a problem to be solved urgently for titanium salt coagulants.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for preparing titanium polychloride by a hydrothermal synthesis method, which has simple preparation process and no addition of additional chemical reagents.

In order to achieve the purpose, the invention adopts the following technical scheme.

A preparation method of the titanium polychloride comprises the following steps: and reacting the titanium tetrachloride solution under a hydrothermal condition to obtain a titanium polychloride solution.

The hydrothermal temperature is 50-80 ℃, and the hydrothermal time is 15-180 min. The hydrothermal condition is normal pressure.

The volume fraction of the titanium tetrachloride solution is 2-4%.

Preferably, the hydrothermal reaction further comprises a step of standing and aging the titanium polychloride solution.

The preparation method of the titanium tetrachloride solution comprises the following steps: under the conditions of stirring at 800 plus 1000rpm and ice-water bath at 0-4 ℃, dropwise adding titanium tetrachloride with the purity of more than or equal to 99wt% into water at the dropwise adding speed of 0.5-1.0 mL/min, and stirring until the mixture is stable to obtain a colorless transparent titanium tetrachloride mother solution with the volume fraction of 20%; and diluting the titanium tetrachloride mother liquor to obtain a titanium tetrachloride solution.

The invention has the following advantages:

the preparation method of the polymeric titanium chloride inorganic polymeric flocculant takes titanium tetrachloride as a raw material, titanium tetrachloride is diluted and is prepared by a low-temperature hydrothermal method, no other chemical reagent is added except for the raw material of the flocculant, the preparation method is more economic and environment-friendly, the cost is low, and the developed polymeric titanium chloride flocculant can be widely applied to treatment of surface water and wastewater and has the characteristics of simple process, less reagent consumption, economy, environmental protection and the like. The invention provides a novel method for synthesizing a novel polymeric titanium salt flocculating agent, and has important significance for widening the application of the titanium salt flocculating agent in a water treatment process.

Drawings

FIG. 1 is a graph showing the effect of treating surface water with titanium polychloride prepared by a hydrothermal method (temperature condition: 80 ℃);

FIG. 2 is a graph showing the effect of treating surface water with titanium polychloride prepared by a hydrothermal method (temperature condition: 50 ℃ C.).

Detailed Description

The present invention will be further described with reference to the following examples and drawings, but the present invention is not limited to the following examples.

EXAMPLE 1 Synthesis of Polytitanium chloride

(1) Under the stirring condition of 800 rpm, dropwise adding 10 mL of titanium tetrachloride with the mass fraction of 99% into 40 mL of deionized water in an ice water bath at the dropping speed of 0.25 mL/min to prepare a titanium tetrachloride solution with the volume fraction of 20%, and continuing stirring in the ice water bath for 2 hours;

(2) taking 5mL of the titanium tetrachloride solution with the volume fraction of 20%, adding the titanium tetrachloride solution into 45 mL of deionized water, placing the mixture into a reaction kettle, placing the reaction kettle into an oven, and performing hydrothermal treatment at 80 ℃ for 15 min, 30 min and 45 min respectively;

(3) and (3) placing the titanium polychlorid solution obtained in the step (2) in a dark environment at 0 ℃, and curing for 24 hours to obtain the titanium polychlorid flocculating agent.

EXAMPLE 2 Synthesis of Polytitanium chloride

(1) Under the stirring condition of 800 rpm, dropwise adding 10 mL of titanium tetrachloride with the mass fraction of 99% into 40 mL of deionized water in an ice water bath at the dropping speed of 0.25 mL/min to prepare a titanium tetrachloride solution with the volume fraction of 20%, and continuing stirring in the ice water bath for 3 hours;

(2) taking 5mL of the titanium tetrachloride solution with the volume fraction of 20%, adding the titanium tetrachloride solution into 45 mL of deionized water, placing the mixture into a reaction kettle, placing the reaction kettle into an oven, and performing hydrothermal treatment for 1, 2 and 3 hours at 50 ℃;

(3) and (3) placing the titanium polychlorid solution obtained in the step (2) in a dark environment at 4 ℃, and curing for 24 hours to obtain the titanium polychlorid flocculating agent.

Comparative example 1

(2) taking 5mL of the titanium tetrachloride solution with the volume fraction of 20%, and adding the titanium tetrachloride solution into 45 mL of deionized water;

(3) and (3) placing the titanium tetrachloride diluted solution obtained in the step (2) in a dark environment at 0 ℃ for curing for 24 hours.

EXAMPLE 3 purification of surface Water by different flocculants

Taking lake water of the first-class lake in the university of Jinan to perform a test, wherein the absorbance of the water sample at the wavelength of 254 nm is 0.104 +/-0.024 cm^-1Turbidity of 7.22. + -. 0.66 NTU and pH of 8.00. + -. 0.52. The titanium polychloride solutions prepared in the examples 1 and 2 and the titanium tetrachloride diluted solution prepared in the comparative example 1 are applied to water treatment of surface water, and the influence of different temperatures and hydrothermal time on coagulation effect is compared. The coagulation effect is shown in figures 1 and 2:

as can be seen from FIG. 1, the longer the hydrothermal time is, the lower the turbidity of the coagulated water is under the hydrothermal condition of 80 ℃. Compared with a titanium tetrachloride diluted solution, the polymerized titanium chloride prepared by hydrothermal method for 15 min reduces the effluent turbidity, but has low organic matter removal rate, so that UV (ultraviolet) is caused₂₅₄The removal rate is reduced, and the pH value of effluent is not obviously changed; the flocculants prepared by hydrothermal for 30 min and 45 min have the same highest removal rate of organic matters, but the turbidity of the effluent is obviously reduced, and the pH of the effluent is obviously increased. As can be seen from figure 2, the flocculant prepared by hydrothermal for 3h has the highest organic matter removal rate, and the pH of the effluent is obviously improved.

EXAMPLE 4 treatment Effect of different flocculants on wastewater

Taking water in bell-type grit chamber of Jinan Limited company as water sample, and measuring absorbance of the water sample at wavelength of 254 nm to be 0.144 +/-0.031 cm^-1Turbidity was 52.2. + -. 1.47 NTU, pH 7.75. + -. 0.16. The polymeric titanium chloride solutions prepared in examples 1 and 2 and the titanium tetrachloride diluted solution prepared in comparative example 1 were applied to municipal wastewater treatment, and the coagulation effect was determined by residual turbidity and UV₂₅₄The removal rate and the pH value of the effluent are shown in Table 1.

TABLE 1 purification Effect of the Polytitanium chlorides on municipal wastewater obtained under different hydrothermal conditions

As can be seen from Table 1, the titanium polychloride prepared by the method has high turbidity removal efficiency, and the pH of effluent is increased. Wherein, the polymeric titanium chloride flocculant prepared by hydrothermal for 30 min at 80 ℃ has the best effect of removing organic matters.

Comparative example 2

Titanium polychloride was prepared according to the method of example 1, except that the hydrothermal time was 6 hours and 12 hours, respectively, to obtain a white suspension of titanium dioxide and a yellow sol of titanium dioxide, respectively. A titanium polychloride was prepared as in example 2, except that the hydrothermal times were 3.5h, 4.5h and 6h, respectively, to obtain white suspensions of titanium dioxide. No matter the temperature is high or low, the polymeric titanium chloride can not be obtained after the hydrothermal time is too long.

Comparative example 3

A titanium polychloride was prepared as in example 2 with hydrothermal times of 1h and 3h, respectively, except that in step (2), 1mL of a 20 volume percent titanium tetrachloride solution was added to 49 mL of deionized water to obtain a white suspension of titanium dioxide, indicating that a titanium tetrachloride solution of too low a concentration failed to obtain a titanium polychloride.

Claims

1. The preparation method of the titanium polychloride is characterized by comprising the following steps: and reacting the titanium tetrachloride solution under a hydrothermal condition to obtain a titanium polychloride solution.

2. The method according to claim 1, wherein the hydrothermal temperature is 50 to 80 ℃ and the hydrothermal time is 15 to 180 min.

3. The method according to claim 1, wherein the hydrothermal pressure is atmospheric pressure.

4. The production method according to claim 1, wherein the volume fraction of the titanium tetrachloride solution is 2 to 4%.

5. The method according to claim 1, further comprising a step of aging the titanium polychloride solution by standing after the hydrothermal reaction.