CN103230705B - Modified ceramic filter material and applications thereof - Google Patents

Abstract

The invention provides a modified ceramic filter material and application thereof. The modified ceramic filter material can be prepared by the following methods: 1) pretreatment of the ceramic filter material; 2) preparation of a modified solution: dissolving cyclodextrin in dimethylformamide solvent to obtain a cyclodextrin solution; according to the cyclodextrin The molar ratio of alcohol to isocyanate is 1:7-8. The isocyanate is added dropwise into the reactor, mixed with the cyclodextrin solution and stirred, and at the same time, ultraviolet light is initiated; after the reaction, the product is washed and dried to obtain the cyclodextrin- Isocyanate copolymer; mix the copolymer with water and stir to obtain a suspension solution; 3) Take the ceramic filter material, and then add the suspension solution obtained in step 2), the amount of the suspension solution can be sealed The ceramic filter material shall prevail, then stirred, dried and roasted to obtain the modified ceramic filter material. The modified ceramic filter material obtained by the method has simple preparation process, rapid response, high mechanical strength of the filter material, long service life, remarkable treatment effect of p-chlorobenzene wastewater, strong practicability and broad prospect.

Description

Modified ceramic filter material and its application

technical field

The invention relates to the field of sewage treatment, in particular to a modified ceramic filter material and its application.

Background technique

The modified filter material is to coat a layer of modifier on the surface of the carrier filter material through physical and chemical reactions, thereby changing the physical and chemical properties of the original filter material surface, thereby improving the ability of the filter material to intercept pollutants, and improving the filter material’s resistance to certain special substances. The adsorption capacity improves the effluent water quality. Modified ceramic filter materials have been widely used as modified filter materials in recent years. The study of modifiers has also made considerable progress. The selection of modifiers should meet the conditions of easy loading, insolubility, non-toxic and harmless. At present, there are many kinds of modifiers and different preparation methods, but further research is still needed to find modifiers that are simple to prepare and have a significant effect on the removal of organic chlorides by adsorption and filtration.

Contents of the invention

The object of the present invention is to provide a modified ceramic filter material with simple preparation method and remarkable effect on removing organic chlorides and its application.

In order to achieve the above object, the technical solution adopted in the present invention is:

Modified ceramic filter material is characterized in that it can be prepared by the following method:

1) Pretreatment of ceramic filter material: Rinse the ceramic filter material and soak it in HCl solution, then rinse with water until the pH value of the rinse water is close to neutral, and then dry the ceramic filter material;

2) Prepare modification solution: Dissolve cyclodextrin in dimethylformamide solvent to obtain cyclodextrin solution; add the cyclodextrin solution into the reactor, and place the reactor at 30-40°C in a water bath; according to the molar ratio of cyclodextrin to isocyanate is 1:7-8, isocyanate is added dropwise into the reactor and mixed with the cyclodextrin solution and stirred, and ultraviolet light is initiated at the same time; wherein, the power of ultraviolet light is 2 -6kw, reacted for 8-15 minutes; after the reaction, the product was washed and dried to obtain a cyclodextrin-isocyanate copolymer; according to the mass ratio of the copolymer to water, the copolymer was mixed with mixing with water, and stirring to obtain a suspension solution, adjusting the pH value of the suspension solution to 6.5-7.5;

3) Take the ceramic filter material obtained in step 1), and then add the suspension solution obtained in step 2). The temperature is 450-650°C, and the firing time is 2 hours, and the modified ceramic filter material can be obtained.

In the above solution, the particle size of the ceramic filter material in step 1) is 1.0-1.25mm.

In the above scheme, the concentration of the HCl solution in step 1) is 0.1-0.2mol/L, and the soaking time is 12-24h.

In the above solution, the drying temperature in step 1) is 100-120° C., and the drying time is 1-2 hours.

In the above scheme, the rotational speed of mixing and stirring the isocyanate and the cyclodextrin solution in step 2) is 120 r/min.

In the above scheme, the isocyanate is hexamethylene diisocyanate, diphenylmethane diisocyanate, or toluene diisocyanate.

Application of the above-mentioned modified ceramic filter material in removing chlorobenzene in water.

In the above scheme, the method of removing chlorobenzene in water by the modified ceramic filter material is deep bed filtration.

In the above scheme, the thickness of the filter layer of the modified ceramic filter material is 150-350mm, and the filtration rate is 2-8m/h.

In the above scheme, the thickness of the filter layer is 350mm, and the filtration rate is 4m/h.

The beneficial effect of the present invention is that: in the preparation process of the isocyanate-cyclodextrin copolymer synthesized by ultraviolet light, under the action of high-energy ultraviolet light, the reactants can be rapidly excited out of active groups, which accelerates the progress of the synthesis reaction, greatly The time used in the conventional preparation method is shortened, and the prepared copolymer is loaded on the surface of the ceramic filter material to obtain the modified ceramic filter material. The modified ceramic filter material obtained by the method has the advantages of simple preparation process, rapid reaction speed, high mechanical strength of the filter material, long service life, remarkable treatment effect of p-chlorobenzene wastewater, strong practicability and wide prospect.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

Example 1:

The present embodiment provides a modified ceramic filter material, which can be prepared by the following method:

1) Pretreatment ceramic filter material: put the ceramic filter material with a particle size of 1.0-1.25mm in a bucket, rinse it repeatedly with tap water, soak it in HCl solution with a concentration of 0.2mol/L for 24 hours, and then rinse it with distilled water. Until the pH value of the rinse water is close to neutral, then place the ceramic filter material in a tray and dry it in a drying oven at 120°C for 2 hours;

2) Preparation of modification solution: Take 2.643x10 ^-3 mol cyclodextrin at room temperature, add DMF solvent dropwise and stir until the cyclodextrin is completely dissolved to obtain a cyclodextrin solution; add the cyclodextrin solution to the reactor Inside, place the reactor in a water bath at 30-40°C; add 20.428x10 ^-3 mol polymer diphenylmethane diisocyanate dropwise into the reactor, mix and stir with the cyclodextrin solution, and at the same time carry out ultraviolet light Initiation; wherein, the power of the ultraviolet light is 4KW, and the stirring speed is adjusted to be 120r/min, so as to fully contact the reaction; after the reaction, the obtained solid product is washed with DMF solvent, washed again with distilled water, and finally dried in vacuum to obtain a copolymerized Take 7.5g copolymer and place in beaker and add 50mL of distilled water, place the beaker on a magnetic stirrer and stir to obtain a suspension solution, and use NaOH with a concentration of 10mol/L to control the pH value of the solution to 7.5;

3) Take the ceramic filter material obtained in step 1) in a beaker, and then add the suspension solution obtained in step 2). The material in the medium was transferred into a crucible, put into an oven to evaporate the water to dryness, and then transferred to a muffle furnace for roasting at a temperature of 650°C and a roasting time of 2 hours to obtain a modified ceramic filter material.

Embodiment 2 :

The present embodiment provides a modified ceramic filter material, which can be prepared by the following method:

1) Pretreatment of ceramic filter material: put the ceramic filter material with a particle size of 1.0-1.25mm in a bucket, rinse it repeatedly with tap water, soak it in HCl solution with a concentration of 0.1mol/L for 24 hours, and then rinse it with distilled water. Until the pH value of the rinse water is close to neutral, then place the ceramic filter material in a tray and dry it in a drying oven at 110°C for 2 hours;

2) Preparation of modified solution: Take 5g of the copolymer prepared by the method of step 2) in Example 1, put it in a beaker, add 50mL of distilled water, place the beaker on a magnetic stirrer and stir to obtain a suspension solution, and use a concentration of 10mol/ L of NaOH control solution pH value is 7.0;

3) Take the ceramic filter material obtained in step 1) in a beaker, and then add the suspension solution obtained in step 2). The material in the medium was transferred into a crucible, put into an oven to evaporate the water to dryness, and then transferred to a muffle furnace for roasting, the roasting temperature was set at 550°C, and the roasting time was set at 2 hours to obtain a modified ceramic filter material.

In this embodiment, the isocyanate is selected from hexamethylene diisocyanate.

Embodiment 3 :

The present embodiment provides a modified ceramic filter material, which can be prepared by the following method:

1) Pretreatment of ceramic filter material: put the ceramic filter material with a particle size of 1.0-1.25mm in a bucket, rinse it repeatedly with tap water, soak it in HCl solution with a concentration of 0.1mol/L for 24 hours, and then rinse it with distilled water. Until the pH value of the rinse water is close to neutral, then place the ceramic filter material in a tray and dry it in a drying oven at 100°C for 2 hours;

2) Preparation of modified solution: Take 5g of the copolymer prepared by the method of step 2) in Example 1, put it in a beaker, add 50mL of distilled water, place the beaker on a magnetic stirrer and stir to obtain a suspension solution, and use a concentration of 10mol/ The NaOH control solution pH value of L is 6.5;

3) Take the ceramic filter material obtained in step 1) in a beaker, and then add the suspension solution obtained in step 2). The material in the medium was transferred into a crucible, put into an oven to evaporate the water to dryness, and then transferred to a muffle furnace for roasting at a temperature of 450°C and a roasting time of 2 hours to obtain a modified ceramic filter material.

In this embodiment, toluene diisocyanate is selected as the isocyanate.

According to the above examples, the modified ceramic filter material prepared under the conditions of Examples 1-3 is selected, and the obtained filter material is used to study the treatment effect of chlorobenzene-containing wastewater. The specific experiments and results are as follows:

experimental device:

A transparent plexiglass column with a diameter of 25 mm and a height of 1500 mm is used as a model filter column. The modified ceramic filter material used in the filter column has a particle size of 1.0-1.25mm, a filter layer thickness of 150-350mm, and a filtration rate of 2-8m/h. Gravel is used as the supporting layer, and the particle size gradually increases from top to bottom, with a total thickness of 100mm.

Raw water preparation: Dissolve chlorobenzene standard sample in distilled water to prepare simulated wastewater.

(1) Treatment experiments of chlorobenzene wastewater with different concentrations:

Take the chlorobenzene standard sample and prepare four water samples with concentrations of 5mg/L, 20mg/L, and 50mg/L with distilled water, numbered A and B respectively. The filter material in the experimental device filter column that A water sample adopts is the ceramic filter material before modification, as a comparative example, B adopts the modified ceramic filter material of Example 2 of the present invention, and the thickness of the filter layer in the experimental device filter column is 350mm , the filtration rate is 4m/h, and the two water samples are filtered through the filter column respectively. Keep the flow of water in and out as stable as possible during filtration.

When the concentration of chlorobenzene is 5mg/L, the removal results of chlorobenzene are shown in the following table 1:

Table 1

When the concentration of chlorobenzene is 20mg/L, the removal results of chlorobenzene are shown in the following table 2:

Table 2

When the concentration of chlorobenzene is 50mg/L, the removal results of chlorobenzene are shown in the following table 3:

table 3

From the above experimental results, it can be concluded that the modified ceramic filter material of the present invention has a remarkable removal effect on chlorobenzene wastewater of different concentrations. Compared with the ceramic filter material before modification, the removal rate has been greatly improved. This is because the copolymer modifier loaded on the surface of the ceramic filter material works synergistically with the ceramic filter material. Not one, the high porosity is often not fully utilized, and its adsorption effect cannot be maximized when acting alone. After modification, the copolymer modifier can quickly and effectively adsorb pollutants in water. Even the copolymer loaded in deep pores can absorb and remove pollutants with its strong adsorption groups. At the same time, the high porosity and high specific surface area of the ceramic filter material also provide a shelter for the copolymer modifier, and the two cooperate to adsorb and remove chlorobenzene in water.

(2) Experiments on the treatment of chlorobenzene wastewater with different filter thicknesses:

The chlorobenzene standard sample was prepared with distilled water to prepare four water samples with a concentration of 20 mg/L, numbered E and F respectively, and three groups of the same water samples were set up for subsequent experiments. Filter material in the experimental device filter column that E water sample adopts is the ceramic filter material before modification, F adopts the ceramic filter material after the modification of the embodiment of the present invention 2, and the thickness of the filter layer in the experimental device filter column is respectively 150mm, 250mm, 350mm, the filtration rate is 4m/h, and the two water samples are filtered through the filter column respectively. Keep the flow of water in and out as stable as possible during filtration.

When the thickness of the filter layer is 150mm, the removal results of chlorobenzene are shown in Table 4 below:

Table 4

When the thickness of the filter layer is 250mm, the removal results of chlorobenzene are shown in Table 5 below:

table 5

The thickness of the filter layer is 350mm, and the removal results of chlorobenzene are shown in Table 6 below:

Table 6

From the above experimental results, it can be concluded that within a certain filter thickness range, the filter material before modification and after modification has a certain effect on the removal of p-chlorobenzene. In comparison, the modified ceramic filter material of the present invention Compared with that before modification, the removal rate is greatly improved, and with the increase of the thickness of the filter layer, the removal rate of chlorobenzene also increases.

(3) Experiments on the treatment of chlorobenzene wastewater at different filtration rates:

The chlorobenzene standard sample was prepared with distilled water to prepare two water samples with a concentration of 20 mg/L, numbered G and H respectively, and 4 groups of the same water samples were set up for subsequent experiments. The filter material in the filter column of the experimental device adopted by G water sample is the ceramic filter material before modification, H adopts the modified ceramic filter material in Example 2, the thickness of the filter layer in the filter column of the experimental device is 350mm, and the filtration rate is 2m respectively /h, 4m/h, 6m/h, 8m/h, the two water samples are filtered through the filter column respectively. Keep the flow of water in and out as stable as possible during filtration.

When the filtration rate is 2m/h, the removal results of chlorobenzene are shown in Table 7 below:

Table 7

When the filtration rate is 4m/h, the removal results of chlorobenzene are shown in Table 8 below:

Table 8

When the filtration rate is 6m/h, the removal results of chlorobenzene are shown in Table 9 below:

Table 9

When the filtration rate is 8m/h, the removal results of chlorobenzene are shown in Table 10 below:

Table 10

From the above experimental results, it can be concluded that within a certain filtration rate range, both the pre-modified and the modified filter materials have certain effects on the removal of p-chlorobenzene. In comparison, the removal rate after modification is greatly improved. In addition, with the increase of the filtration rate, the removal rate of the two filter materials decreases, but compared with the filter material before modification, the reduction of the removal rate of the modified ceramic filter material of the present invention is not obvious. Considering the overall technical and economic factors comprehensively, 4m/h filtration rate can be selected in practical application.

Select the modified ceramic filter material prepared under the conditions of Example 1 and Example 3, refer to the above experiment, choose the concentration of chlorobenzene to be 20mg/L, the thickness of the filter layer is 350mm, and the filtration rate is 4m/h to explore the chlorobenzene-containing wastewater. Treatment effect, chlorobenzene removal result is shown in the following table 11:

Table 11

The ceramic filter material used in the embodiment of the present invention is a ceramic filter material prepared according to the Chinese patent application number 200810197939.6, and the title of the invention is "Method for Preparing Environmentally Friendly Ceramic Filter Material Using Magnesium Slag". It can be understood that other commercially available ceramic filter materials can also be used in the present invention.

Claims (10)

1. modified ceramic filtrate, is characterized in that, it is prepared by following method:

1) pretreatment ceramic filter material: soak with HCl solution after being rinsed by ceramic filter material, then rinses with water until the pH value of flushing water is close to neutral, then ceramic filter material is dry;

2) modified solution is prepared: by cyclodextrin in solvent dimethylformamide, obtain cyclodextrin solution; Be added in reactor by described cyclodextrin solution, described reactor is placed in the water-bath of 30-40 DEG C; Be that isocyanates to drop in reactor and mixes with cyclodextrin solution and stir by 1:7-8 according to cyclodextrin and the mol ratio of isocyanates, carry out ultraviolet light initiation simultaneously; Wherein, the power of ultraviolet light is 2-6kw, reaction 8-15 minute; Reaction terminates to wash product afterwards, dry, obtain cyclodextrin-isocyanate copolymer; Be that described copolymer mixes with water by 0.1-0.15:1 according to described copolymer and the mass ratio of water, and stir and obtain suspension solution, regulate the pH value of described suspension solution to be 6.5-7.5;

3) get the ceramic filter material of step 1) gained, then add step 2) the suspension solution of gained, the addition of described suspension solution is as the criterion can seal ceramic filter material, then stirring, dry, roasting, sintering temperature is 450-650 DEG C, and roasting time is 2h, namely obtains modified ceramic filtrate.

2. modified ceramic filtrate as claimed in claim 1, it is characterized in that, the particle diameter of the ceramic filter material in described step 1) is 1.0-1.25mm.

3. modified ceramic filtrate as claimed in claim 1, it is characterized in that, the concentration of the HCl solution in described step 1) is 0.1-0.2mol/L, and soak time is 12-24h.

4. modified ceramic filtrate as claimed in claim 1, it is characterized in that, the baking temperature in described step 1) is 100-120 DEG C, and drying time is 1-2h.

5. modified ceramic filtrate as claimed in claim 1, is characterized in that, described step 2) in isocyanates and the rotating speed of cyclodextrin solution mix and blend be 120r/min.

6. modified ceramic filtrate as claimed in claim 1, it is characterized in that, described isocyanates is hexamethylene diisocyanate, methyl diphenylene diisocyanate or toluene di-isocyanate(TDI).

7. the application of chlorobenzene in water removed by the modified ceramic filtrate as described in any one of claim 1-6.

8. apply as claimed in claim 7, it is characterized in that, the mode that chlorobenzene in water removed by described modified ceramic filtrate is deep-bed filtration.

9. apply as claimed in claim 7, it is characterized in that, described modified ceramic filtrate thickness of filter bed is 150-350mm, and filtering velocity is 2-8m/h.

10. apply as claimed in claim 9, it is characterized in that, described thickness of filter bed is 350mm, and filtering velocity is 4m/h.