CN104959130B - Chelate adsorption function resin, its preparation method and application - Google Patents

Abstract

The invention discloses a chelating adsorption functional resin, its preparation method and application, comprising the following steps: 1) soaking chlorine balls in N,N-dimethylamide (DMF) as a reaction solvent until the chlorine balls Fully swell; 2), add methylpiperazine (MPP) as a ligand to the result of step 1), and stir the reaction at 100~120°C for 10~12 hours under the condition of nitrogen protection; among them, methyl The ratio of the amount of piperazine (MPP) to ‑CH ₂ Cl in chlorine balls is 3.8~4.2:1; 3), filter the product of step 2) to obtain a filter cake, and use the filter cake as a reaction solvent N,N-Dimethylamide (DMF) was soaked and washed 3~4 times, and then washed with distilled water, acetone, ether, and absolute ethanol in sequence; vacuum-dried at 40~60°C to constant weight to obtain a resin with chelating adsorption function. The chelating adsorption functional resin provided by the invention has the characteristics of selective adsorption to Mn(VII) in aqueous solution, good adsorption performance, reusability and the like.

Description

Chelating adsorption functional resin, its preparation method and application

technical field

The invention relates to a preparation method of a chelating adsorption functional resin, in particular to a preparation method of a modified chelating functional adsorption resin capable of selectively adsorbing Mn(VII) in an aqueous solution, having good adsorption performance and being reusable.

Background technique

During the industrial production of potassium permanganate (KMnO ₄ ), the residue after water leaching is called manganese sludge. The waste of manganese slime is not only a waste of manganese resources, but also causes alkali pollution and "red water" pollution. The generation of red water is caused by the disproportionation reaction of manganese mud adsorption and entrained potassium manganate solution to generate potassium permanganate solution. Experimental research has found that both manganese and iron have a high leaching rate when manganese mud is leached. Therefore, when manganese products are prepared from the leachate by separation and enrichment, there is also the problem of iron ion interference. There are many separation and enrichment methods commonly used: such as membrane separation method, solvent extraction method, electrochemical reduction method, chemical precipitation method, ion exchange resin method, chelation adsorption material enrichment method, etc. The cost of materials used in the membrane separation method is high; the operation process of the solvent extraction method is extremely cumbersome, and the volatility, toxicity and high cost of organic solvents also limit its practical application; the energy consumption of the electrochemical reduction method is too high; chemical precipitation The method is relatively common, but the precipitant used in it is often expensive, and the effect is not good when dealing with lower concentrations of metal ions; the ion exchange resin treatment method is simple to operate, low in cost but poor in selectivity; It has the advantages of large adsorption capacity, high enrichment factor, good selectivity, simple operation, easy resin regeneration, and acid and alkali resistance, so it is widely used in the selective separation and enrichment of trace metal ions in aqueous solutions.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a kind of chelating adsorption functional resin, its preparation method and application, have the characteristics of simple preparation process and low cost, and the chelating adsorption functional resin prepared by the present invention has a strong effect on Mn(VII) ions It has high selective adsorption capacity.

In order to solve the above-mentioned technical problem, the present invention provides a kind of preparation method of chelating adsorption function resin, take chlorine ball as matrix, methylpiperazine (MPP) is ligand, the benzyl group on the chlorine ball is modified, chlorine ball It is a macroporous chloromethylation cross-linked polystyrene microsphere; comprising the following steps:

1), soak the chlorine ball in N, N-dimethylamide (DMF) as a reaction solvent until the chlorine ball is fully swollen;

2), adding methylpiperazine (MPP) as a ligand to the obtained product of step 1), stirring and reacting at 100-120° C. for 10-12 hours under the condition of nitrogen protection; wherein, methylpiperazine ( The ratio of MPP) to the amount of -CH ₂ Cl in the chlorine ball is 3.8-4.2:1;

3), filter the product of step 2) to obtain a filter cake, soak and wash the filter cake with N,N-dimethylamide (DMF) as a reaction solvent for 3 to 4 times, and then successively wash with distilled water, acetone, ether, Washing with absolute ethanol; vacuum-drying at 40-60°C to constant weight to obtain a resin with chelating adsorption function.

Preferably, in step 1), the dosage ratio of chlorine bulbs to N,N-dimethylamide is: 1mg chlorine bulbs/1-2ml of N,N-dimethylamide, and the soaking time is 22-26 hours.

Preferably, in step 2), the reaction temperature is 120°C.

Preferably, in step 2), the reaction time is 10 hours.

The present invention also provides the chelating adsorption functional resin prepared by the above method.

The chelating adsorption functional resin prepared by the method of the present invention is used for adsorbing heptavalent manganese ions. Wherein, the adsorption condition is pH 5.0.

The chelating adsorption functional resin (hereinafter referred to as PS-MPP) that adopts the inventive method to prepare, carries out following experiment:

1. Heavy metal ion adsorption experiment:

The adsorption experiment is carried out in a constant temperature oscillator. Accurately weigh a certain amount (for example, 15.0mg) of PS-MPP into a 100ml iodine measuring bottle, and add a certain volume of 25ml of acetic acid with a certain pH value (for example, a pH value of 5.0) Soak in sodium acetate buffer solution (hereinafter referred to as HAc-NaAc buffer solution) for 24 hours, then add a certain amount (for example, 5ml) of prepared heavy metal ion standard solution, and perform adsorption operation under stirring. Measure and analyze the residual metal ion concentration in the water phase at regular intervals until equilibrium. Use the following formula to calculate the adsorption capacity (Q _e ) and distribution ratio (D):

where Q _e is the adsorption capacity of PS-MPP at equilibrium (mg g ^-1 ); C _o and C _e are the initial concentration (mg mL ^-1 ) and equilibrium concentration (mg mL -1 ) of metal ions in the water phase, respectively. ^-1 ); m is the quality (g) of PS-MPP; V is the liquid volume (mL), which refers to the sum of the heavy metal ion standard solution and the buffer solution volume.

2. Desorption experiment

Accurately weigh 3 parts of 15.0mg PS-MPP and add 5ml of 0.700mg/ml metal ion solution respectively, add 25ml of HAc-NaAc buffer solution at a certain pH value (pH value is 5.0), the total volume is 30ml at 298K, 100r/min Oscillating adsorption at rotating speed, after adsorption equilibrium. Filter the resin, wash with HAc-NaAc buffer solution (pH value 5.0) and distilled water for 3 times, dry it at low temperature and place it in the iodine bottle, add 30ml concentration of 0.5mol/l, 1.0mol/l, 2.0mol /l, 5.0mol/l, 6.0mol/l sodium hydroxide desorption solution, shake at constant temperature to balance and measure the concentration of heavy metal ions in the solution. The desorption rate of the adsorbent was calculated according to the following formula:

In the formula, C _d is the equilibrium concentration of metal ions in the desorbent (mg·mL ^-1 ); V _d is the volume of desorption solution used (mL). C _o and C _e are the initial concentration (mg·mL ^-1 ) and equilibrium concentration (mg·mL ^-1 ) of metal ions in the water phase, respectively; V is the volume of the liquid phase (mL).

Compared with the prior art, the present invention has the following advantages:

1. The raw material of the chelating adsorption functional resin prepared by the present invention is chlorine balls, which has high mechanical strength and physical stability, has a wide range of sources, is cheap, and has obvious economic benefits.

2. The present invention uses the chemical grafting method to modify the chlorine balls so that it has greater chemical stability, and enhances the ability to resist acids, alkalis and organic solvents and its adsorption capacity.

3. The PS-MPP prepared by the method of the present invention has higher selective adsorption to Mn(VII), large adsorption capacity, fast adsorption speed, and basically no adsorption to Fe(III).

4. The chelating adsorption functional resin prepared by the present invention has good chemical stability, can be eluted, reduces secondary pollution, and is convenient for repeated use.

5. The preparation method of the chelating adsorption functional resin of the present invention is easy to operate and has high yield.

Description of drawings

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is the reaction schematic diagram of the present invention;

Fig. 2 is the influence of reaction molar ratio on the conversion rate of chlorine ball functional group;

Fig. 3 is the impact of reaction temperature on the conversion rate of chlorine ball functional group;

Fig. 4 is the impact of reaction time on the conversion rate of chlorine spherical functional group;

Figure 5 is the effect of PS-MPP on the adsorption capacity of metal ions Mn(VII), Fe(III) under different pH values;

Fig. 6 is the effect of PS-MPP on the adsorption amount of metal ion Mn(VII) under different time and temperature.

detailed description

The present invention will be further described below in conjunction with specific embodiments, but the content of the present invention is not limited thereto.

Remarks: the water washing in the following examples is all washing with distilled water.

Example 1

A preparation method for a preparation method of a chelating adsorption functional resin, comprising the following steps:

1) At room temperature, accurately weigh 20.0㎎ of chlorine balls into a 100ml three-necked bottle, add 30ml of N,N-dimethylamide (DMF), soak overnight (about 24 hours) to fully swell the chlorine balls;

2), adding methylpiperazine (MPP) as a ligand to the resultant of step 1), the ratio of the amount of methylpiperazine (MPP) to the amount of -CH ₂ Cl on the chlorine ball is 4:1, Under the protection condition of nitrogen, keep the reaction temperature of 120 DEG C and stir (rotating speed is 100r/min) to react for 12 hours;

3), after the reaction is completed, filter the product of step 2), and soak and wash the obtained filter cake with N,N-dimethylamide (DMF) for 3 to 4 times (each dosage is 40ml), and then use Distilled water, acetone, ether, absolute ethanol washing, repeated 4 times (each time, the consumption of distilled water is 40ml, the consumption of acetone is 40ml, the consumption of ether is 40ml, the consumption of absolute ethanol is 40ml); 50 ℃ of vacuum drying to Constant weight, obtains chelating adsorption functional resin (abbreviated as PS-MPP).

Wherein, macroporous chloromethylated cross-linked polystyrene microspheres (also known as macroporous chloromethylated cross-linked polystyrene, PS-CH ₂ Cl, hereinafter referred to as chlorine balls) belong to the prior art, for example It can be purchased from Nankai University Chemical Plant, etc., with a cross-linking degree of 8%.

Experiment 1

Accurately weigh 4 parts of each 20.0㎎ chlorine ball and place it in a 100ml iodine bottle, add 30ml of DMF and soak for 24h to make the chlorine ball fully swell, then add a certain amount of methylpiperazine (methylpiperazine) as a ligand respectively The mass ratios of oxazine to -CH ₂ Cl in chlorine balls were 2:1, 3:1, 4:1, 5:1), and the reaction was stirred at 120° C. for 10 h under nitrogen protection. After the reaction, filter, and soak and wash the obtained filter cake with DMF for 3 to 4 times, then repeatedly wash with distilled water, acetone, ether, and absolute ethanol several times (for example, 4 times), and vacuum-dry at 50°C to constant weight . Calculate the functional group conversion rate according to the following formula to obtain the optimal synthesis conditions of the resin of the present invention. The functional base conversion rate was calculated according to the following formula:

In the formula, N% is the resin nitrogen content after the synthesis that elemental analysis records, and a contains the number of N atoms in every molecular ligand; M _N is the molar mass of N atoms _; Functional group (-CH ₂ Cl) content; ΔM is the weight gain of the resin after conversion of 1 mol functional group (g/mol); x is the functional group conversion rate of the resin.

The experimental results are shown in Figure 2. According to Figure 2, it is known that: when the molar ratio is low, the functional group conversion rate of the resin increases with the increase of the molar ratio; but as the molar ratio continues to increase, the functional group conversion of the resin increases. The rate did not increase significantly, which may be because the active site of the parent has fully contacted with the ligand to reach a saturated state, so it is difficult to increase the conversion rate of functional groups by continuing to increase the concentration. Therefore, it is finally determined that the optimum reaction molar ratio of PS-MPP is 4:1; that is, the optimal ratio of the amount of methylpiperazine (MPP) to -CH ₂ Cl in the chlorine sphere is 4:1.

Experiment 2

Accurately weigh 5 parts of each 20.0㎎ chlorine ball and place it in a 100ml iodine bottle, add 30ml of DMF and soak for 24h to make the chlorine ball fully swell, then add a certain amount of methylpiperazine (methylpiperazine) as a ligand respectively The mass ratio of -CH ₂ Cl in oxazine to chlorine balls is 4:1), under nitrogen protection conditions at 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C The reaction was stirred for 10h. After the reaction, the resin was filtered out, soaked and washed with DMF for 3 to 4 times, then washed several times (for example, 4 times) with distilled water, acetone, ether, and absolute ethanol in sequence, and dried in vacuum at 50°C to constant weight. Calculate the conversion rate of functional groups according to the following formula to obtain the optimal synthesis conditions of the resin.

Wherein, the calculation method of the conversion rate of functional groups refers to the description in Experiment 1. The results of this experiment are shown in Figure 3.

According to Figure 3, it is known that: when the reaction temperature is low, the conversion rate of the functional group of the resin increases with the increase of the temperature; but after reaching a certain temperature, continuing to increase the temperature cannot continue to significantly increase the conversion rate of the functional group. Considering the experimental conditions and synthesis efficiency, the optimum synthesis temperature of PS-MPP was determined to be 120℃.

Experiment 3

Accurately weigh 5 parts of each 20.0㎎ chlorine ball and place it in a 100ml iodine bottle, add 30ml of DMF and soak for 24h to make the chlorine ball fully swell, then add a certain amount of methylpiperazine (methylpiperazine) as a ligand respectively The mass ratios of oxazine and -CH2Cl in the chlorine balls were 4:1), and the reaction was stirred and reacted at 120° C. for 6h, 8h, 10h, and 12h under nitrogen protection conditions. After the reaction, the resin was filtered out, soaked and washed with DMF for 3 to 4 times, then washed several times (for example, 4 times) with distilled water, acetone, ether, and absolute ethanol in sequence, and dried in vacuum at 50°C to constant weight.

Wherein, the calculation method of the conversion rate of functional groups refers to the description in Experiment 1. The results of this experiment are shown in Figure 4.

According to Figure 4, it is known that when the reaction temperature is constant, the conversion rate of the functional group of the resin increases with time; but after a certain period of time, the conversion rate of the functional group cannot continue to be significantly improved by extending the time, but decreases to some extent. . Considering the experimental conditions and synthesis efficiency, the optimal synthesis time of PS-MPP was finally determined to be 10h.

Experiment 4

Accurately weigh 7 parts of each 15.0 mg PS-MPP resin obtained in the present invention and place it in a 100 ml iodine measuring bottle, and add 20 ml of pH=3.0, pH=3.5, pH=4.0, pH=4.5, pH=5.0 respectively , pH=5.5, pH=6.0, pH=6.5 in the HAc-NaAc buffer solution soaked for 24h, each part was added 5.0mL, 0.700mg/mL Mn(VII) ion solution (prepared by using potassium permanganate) and 5.0mL, 0.700mg/mL Fe(III) ion solution (formed by using ferric chloride) placed in a constant temperature oscillator at 298K, shaken at a constant temperature at a speed of 100r/min, and measured at regular intervals Analyze the residual metal ion concentration in the aqueous phase until equilibrium. According to the above method, the effect of pH on the adsorption properties of heptavalent manganese ions and ferric ions by the modified chelating functional resin can be obtained. The results obtained are shown in Figure 5.

According to Fig. 5, know: the chelating functional resin (PS-MPP resin) after the modification is to the optimum adsorption pH value of Mn(VII) ion solution is 5.0, can contain Fe(III), Mn(VII) simultaneously Selective adsorption of Mn(VII) in the mixed solution of Fe(III) and no adsorption of Fe(III).

Experiment 5

Accurately take by weighing 3 parts of PS-MPP resin that each part is the gained of the present invention of 30.0mg, add respectively 50ml HAc-NaAc buffer solution (pH is 5.0) after soaking in 24 hours, add 10.0ml, the Mn of 0.700mg/mL ( VII) Ion solution (prepared by potassium permanganate), absorb at 15°C, 25°C, and 35°C at a constant temperature of 100r/min, and take out a small amount of solution quantitatively after a certain period of time to measure metal ions concentration until adsorption equilibrium. The results obtained are shown in Figure 6.

According to Figure 6, it is known that the adsorption rate of the resin is relatively large at the beginning; as the adsorption progresses, the rate gradually decreases; finally, it reaches equilibrium. And as the temperature increases, the adsorption capacity of the resin to the heavy metal ion Mn(VII) also increases. It can be seen from Figure 6 that the adsorption equilibrium time of the PS-MPP resin of the present invention to the heptavalent manganese ion is 40h.

In summary, the optimal synthesis condition of the chelating adsorption functional resin (PS-MPP resin) of the present invention is: the ratio of the amount of substance of -CH in methylpiperazine and chlorine spheres Cl is ₄ :1, The synthesis reaction temperature is 120°C, the synthesis reaction time is 10 hours, the conversion rate of the functional group of the obtained chlorine ball is 88.68%; the optimum adsorption condition is: the optimum adsorption pH value is 5.0, and the obtained adsorption effect is: 47.5mg/g .

Experiment 6

Accurately take by weighing each part is 15.0mg PS-MPP3 parts of the present invention's gained, every part adds the Mn(VII) ion solution (for adopting potassium permanganate to prepare) 5ml of 0.700mg/mL, HAc-NaAc buffer solution ( The pH is 5.0) 25ml, the total volume is 30ml, at 15°C, oscillating adsorption at a rotating speed of 100r/min, after the adsorption is balanced; the resin is filtered and washed 3 times with HAc-NaAc (pH is 5.0) and distilled water successively (each time , the consumption of HAc-NaAc is 40ml, the consumption of distilled water is 40ml), adding 30ml concentration is respectively 0.5mol/l, 1.0mol/l, 2.0mol/l, 5.0mol/l, the sodium hydroxide desorption solution of 6mol/l , after the analysis is complete, the metal ion concentration is measured. The obtained results are shown in Table 1.

Table 1 Desorption rate of PS-MPP under different NaOH concentrations

Comparative example 1

Change the methylpiperazine resin used as the adsorption material in Example 1 into chitosan (CTS). Others are with embodiment 1.

The CTS was detected according to the method of Experiment 4, and the optimal adsorption condition was: the optimal adsorption pH value was 3.0, and the obtained optimal adsorption effect on Mn(VII) was: 11 mg/g. The adsorption capacity is much lower than that of the PS-MPP resin in Example 1.

Comparative example 2

Change the methylpiperazine as ligand in embodiment 1 into 4-aminoantipyrine (AATP), 2-amino-6-chloropurine (ACP), 2-mercaptobenzothiazole (MPTZ), pull Motrigine (LMTG), the chlorine sphere is modified, and others are the same as in Example 1.

The four modified materials in the comparative example were tested according to the method of Experiment 4, and none of them had obvious adsorption effect on Mn(VII).

The above embodiments do not limit the present invention in any way, and all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (5)

1. a kind of preparation method for chelating adsorption function resin, it is characterized in that：Using chlorine ball as parent, methyl piperazine is part, right Benzyl on chlorine ball is modified, and the chlorine ball is macroporous type chloroethyl crosslinked polystyrene microballoon；Comprise the following steps：

1), chlorine ball is immersed in the N as reaction dissolvent, N-dimethylformamide, until chlorine ball is fully swelled；

2), in step 1) gains in add the methyl piperazine as part, nitrogen protection under conditions of in 100~120 Stirring reaction 10~12 hours at DEG C, wherein, the methyl piperazine and the-CH in chlorine ball₂The ratio between Cl amount of material be 3.8~ 4.2：1；

3), filtration step 2) gains, obtain filter cake, filter cake be used as to the N of reaction dissolvent, N-dimethylformamide immersion is washed Wash 3~4 times, then washed successively with distilled water, acetone, ether, absolute ethyl alcohol；40~60 DEG C are dried under vacuum to constant weight, obtain Chelating adsorption function resin for adsorbing septivalency manganese ion；

Wherein, the step 1) in：The amount ratio of chlorine ball and N, N-dimethylformamide is：1mg chlorine ball/1~2ml N, N-bis- Methyl nitrosourea, soak time is 22~26 hours.

2. preparation method according to claim 1, it is characterized in that：

The step 2) in, the methyl piperazine and the-CH in chlorine ball₂The ratio between Cl amount of material is 4：1.

3. preparation method according to claim 1, it is characterized in that：

The step 2) in, reaction temperature is 120 DEG C.

4. preparation method according to claim 1, it is characterized in that：

Adsorption conditionses are that pH value is 5.0.

5. one kind chelating adsorption function resin, it is characterized in that, obtained as the preparation method described in any one of Claims 1-4.