Summary of the invention
An object of the present invention is uneven in order to solve above-mentioned nano zero valence iron particle size distribution, and easily reunite, the technical problems such as reactivity is low provide nanometer nulvalent iron particle of a kind of support type and preparation method thereof.The nanometer nulvalent iron particle of this support type has nano zero valence iron particle size distribution evenly, not easily reunites, reactivity high feature.
Two of object of the present invention is to provide the preparation method of the nanometer nulvalent iron particle of above-mentioned a kind of support type, and this preparation method is carrier with sepiolite, utilizes liquid phase reduction by nano zero valence iron particulate load on sepiolite, its preparation method, simple process, easy to operate, equipment needed thereby is simple.
Know-why of the present invention
Utilize NaBH
4or KBH
4strong reducing property by Fe
3+reduction obtains Fe
0, its reaction equation is:
。
Technical scheme of the present invention
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, has nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads;
Be 5-20nm at the particle diameter of the nanometer nulvalent iron particle of the area load of modified meerschaum carrier, preferred 3-7nm, and be about 0.01-1nm at the diameter of the nanometer nulvalent iron particle of the internal load of modified meerschaum, be preferably 1nm.
The preparation method of the nanometer nulvalent iron particle of above-mentioned a kind of support type, specifically comprises the following steps:
(1), the preparation of modified meerschaum
The aqueous hydrochloric acid solution that mass percent concentration is 15% is added in natural sepiolite powder, then abundant mix and blend 48h at 25-30 DEG C, then it is neutral for washing to efflux with deionized deoxygenated water, then control temperature is 115-125 DEG C and carries out drying, then control temperature is 310-330 DEG C and carries out roasting, then grind, cross 160-200 mesh sieve, the powder of gained is modified meerschaum;
Mass percent concentration is the consumption of the aqueous hydrochloric acid solution of 15%, calculates in mass ratio, i.e. natural sepiolite powder: mass percent concentration be 15% aqueous hydrochloric acid solution be 1:5;
(2), containing the preparation of the modified meerschaum solution of iron ion
The above-mentioned 6g modified meerschaum of step (1) gained is added the FeCl that 100mL concentration is 0.1-0.3mol/L
3in the aqueous solution, under room temperature fully after mixing 12h, controlling rotating speed, to be that 8000-10000r/min carries out centrifugal to remove unnecessary iron ion, and the precipitation obtained is with being the FeCl of 0.1-0.3mol/L with concentration
3the isopyknic deionized deoxygenated water of the aqueous solution dissolves, and is then 3.0 with the NaOH aqueous solution tune pH of concentration to be the HCl aqueous solution of 0.5mol/L and concentration be 0.5mol/L, obtains the modified meerschaum solution containing iron ion;
Above-mentioned modified meerschaum and concentration are the FeCl of 0.1-0.3mol/L
3the consumption of the aqueous solution, by modified meerschaum: concentration is the FeCl of 0.1-0.3mol/L
3the aqueous solution is that the ratio of 3g:50ml calculates;
(3), the preparation of nano zero-valence ferrous solution
With N
2for protection, be under the condition of 300-340r/min at rotating speed, is that 15-20ml/min adds reducing agent to step (2) gained containing controlling drop rate in the modified meerschaum solution of iron ion, after adding, continuing to control rotating speed is that 300-340r/min stirs 30-60min, obtains the nano zero-valence ferrous solution of black;
The NaBH of described reducing agent to be concentration be 0.4-1.5mol/L
4the aqueous solution or concentration are the KBH of 0.4-1.5mol/L
4the aqueous solution, the consumption of reducing agent, calculates in molar ratio, the boron hydracid radical ion namely in reducing agent: be 4-5:1 containing the iron ion in the modified meerschaum solution of iron ion;
(4), the preparation of the nanometer nulvalent iron particle of support type
Nano zero-valence ferrous solution through the black of step (3) gained controls rotating speed, and to be that 8000-10000r/min carry out centrifugal, the precipitation of gained is successively with deionized deoxygenated water, straight alcohol washing 3-5 time, then control temperature is 60-70 DEG C and carries out vacuum drying, obtains the nanometer nulvalent iron particle of support type.
The nanometer nulvalent iron particle of the support type of above-mentioned gained, due to the nanometer nulvalent iron particle distribution uniform of institute's load, average grain diameter is less, the particle size distribution range of the nanometer nulvalent iron particle of sepiolite surface institute load is 5-20nm, and the diameter of the nanometer nulvalent iron particle of sepiolite internal load is about 0.01-1nm, than some other loaded nano Zero-valent Iron, it has less particle size distribution range, larger specific area, higher removal efficiency is had to pollutant, therefore it not only can be applied to the removal of underground water pollutant, but also the pollutant that can be applied in rehabilitating soil, there is better practical significance and engineer applied value, in the specific embodiment of the present invention, only be illustrated with the example that is degraded to of the decabromodiphenyl oxide in water, but do not limit the removal of its other pollutants in underground water, and other pollutants be applied in rehabilitating soil.
Beneficial effect of the present invention
The nanometer nulvalent iron particle of a kind of support type of the present invention, because the loaded article adopted is sepiolite, it is widely distributed, cheap, and there is higher adsorptivity, larger specific area, good dispersiveness, iron ion is made very easily to be adsorbed to its surface and to enter in its internal gutter, and then more dispersed nano zero valence iron particle preferably can be formed, the distributing homogeneity of the nanometer nulvalent iron particle in the nanometer nulvalent iron particle of therefore support type, non-oxidizability and anti-agglomeration are obtained for great raising.
Further, the nanometer nulvalent iron particle of support type of the present invention, the nanometer nulvalent iron particle distribution uniform of institute's load, average grain diameter is less, the particle size distribution range of the nanometer nulvalent iron particle of sepiolite surface institute load is 5-20nm, and the diameter of the nanometer nulvalent iron particle of sepiolite internal load is about 0.01-1nm, than some other loaded nano Zero-valent Iron, it has less particle size distribution range, larger specific area, higher removal efficiency is had to pollutant, therefore it not only can be applied to the removal of underground water pollutant, but also the pollutant that can be applied in rehabilitating soil.
Further, the preparation method of the nanometer nulvalent iron particle of support type of the present invention, required equipment is simple, easy to operate, and reaction can complete at normal temperatures and pressures, and therefore cost is low, high financial profit; And the nanometer nulvalent iron particle preparing the support type of gained is solid, and reaction system is aqueous phase, after reaction terminates, both are easily separated, and not easily cause environmental pollution, are therefore applicable to the application of large-scale industrial production.
Detailed description of the invention
Also by reference to the accompanying drawings the present invention is set forth further below by specific embodiment, but do not limit the present invention.
embodiment 1
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, and have nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads, its preparation process specifically comprises the following steps:
(1), the preparation of modified meerschaum
The aqueous hydrochloric acid solution that mass percent concentration is 15% is added in natural sepiolite powder, then abundant mix and blend 48h at 25-30 DEG C, then it is neutral for washing to efflux with deionized deoxygenated water, then control temperature is 115-125 DEG C and carries out drying, then control temperature is 310-330 DEG C and carries out roasting, then grind, cross 160-200 mesh sieve, the powder of gained is modified meerschaum;
Mass percent concentration is the consumption of the aqueous hydrochloric acid solution of 15%, calculates in mass ratio, i.e. natural sepiolite powder: mass percent concentration be 15% aqueous hydrochloric acid solution be 1:5;
(2), containing the preparation of the modified meerschaum solution of iron ion
The modified meerschaum of 6g step (1) gained is joined the FeCl that 100mL concentration is 0.1mol/L
3in the aqueous solution, after fully mixing 12h under room temperature, controlling rotating speed, to be that 8000r/min carries out centrifugal to remove unnecessary iron ion, the precipitation 100ml deionized deoxygenated water obtained dissolves, then adjust pH to be 3.0 with the NaOH aqueous solution of concentration to be the HCl aqueous solution of 0.5mol/L and concentration be 0.5mol/L, obtain the modified meerschaum solution containing iron ion;
Above-mentioned modified meerschaum and concentration are the FeCl of 0.1mol/l
3the consumption of the aqueous solution, by modified meerschaum: concentration is the FeCl of 0.1mol/L
3the aqueous solution is that the ratio of 3g:50ml calculates;
(3), the preparation of nano zero-valence ferrous solution
With N
2for protection, be under the condition of 300r/min at rotating speed, is that 15-20ml/min adds reducing agent to step (2) gained containing controlling drop rate in the modified meerschaum solution of iron ion, after adding, continuing to control rotating speed is that 300r/min stirs 30-60min, obtains the nano zero-valence ferrous solution of black;
The NaBH of described reducing agent to be concentration be 0.4mol/L
4the aqueous solution, the consumption of reducing agent, calculates in molar ratio, the boron hydracid radical ion namely in reducing agent: be 4:1 containing the iron ion in the modified meerschaum solution of iron ion;
(4), the preparation of the nanometer nulvalent iron particle of support type
Nano zero-valence ferrous solution through the black of step (3) gained controls rotating speed, and to be that 8000r/min carries out centrifugal, the precipitation of gained washs 3 times with deionized deoxygenated water, straight alcohol successively, then control temperature is 60 DEG C and carries out vacuum drying, obtains the nanometer nulvalent iron particle of support type.
Adopt transmission electron microscope (JEM 2011, Jeol, Japan) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, the projection Electronic Speculum figure of gained as shown in Figure 1, as can be seen from Figure 1 the nanometer nulvalent iron particle of the support type of gained, take modified meerschaum as carrier, nanometer nulvalent iron particle is had on the surface of modified meerschaum carrier and inner all loads, the particle size distribution range of the nano zero-valence iron ion of surface institute load is 5-20nm, and the diameter of the nanometer nulvalent iron particle of sepiolite internal load is about 0.01nm.
Employing x-ray diffractometer (X ' Pert PW 3040/60, PANalytical, Netherlands) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, the XRD figure of gained as shown in Figure 2, as can be seen from Figure 2, when scanning angle of diffraction 2 θ is 30 °-90 °, in 2 θ=44.8 °, 65.1 °, 82.4 ° place, all there is obvious diffraction maximum, the standard P DF card of contrast iron can be known: just corresponding corresponding 110 crystal face diffraction (Fe-110), 200 crystal face diffraction (Fe-200), 211 crystal face diffraction (Fe-211), the particle indicating preparation is the nanometer nulvalent iron particle of support type.
comparative examples 1
A kind of nanometer nulvalent iron particle, is prepared by a method comprising the following steps and forms:
Preparation process is not except adding modified meerschaum, and other all with the step (2) in embodiment 1, (3), (4), finally obtain nanometer nulvalent iron particle.
application Example 1
The nanometer nulvalent iron particle of the support type of gained in embodiment 1 is utilized to degrade to the decabromodiphenyl oxide (BDE209) in water, to remove decabromodiphenyl oxide (BDE209), simultaneously with the nanometer nulvalent iron particle of gained in the modified meerschaum of step (1) gained in the natural sepiolite powder used of step (1) in embodiment 1, embodiment 1, comparative examples 1 for contrast, step is as follows:
The nanometer nulvalent iron particle of the support type of final gained in 0.8g embodiment 1 is added respectively to 5 parts of 100mL concentration BDE209 aqueous solution that is 2mg/L, the natural sepiolite powder that in 0.8g embodiment 1, step (1) is used, the modified meerschaum of step (1) gained in 0.8g embodiment 1, the nanometer nulvalent iron particle of gained in 10.4mg comparative examples 1, not add any material for blank group, reaction 24h is carried out under normal temperature and pressure, GC/MS is used to measure BDE209 residual in solution in course of reaction, then be abscissa with reaction time, with BDE209 residual rate for ordinate is mapped, obtain the nanometer nulvalent iron particle of the support type of gained in embodiment 1, natural sepiolite powder used in step (1) in embodiment 1, the modified meerschaum of step (1) gained in embodiment 1, in comparative examples 1, the nanometer nulvalent iron particle of gained is with the change in reaction time, it is the removal situation of BDE209 in the BDE209 aqueous solution of 2mg/L to concentration, the results are shown in Figure shown in 3, sepiolite in Fig. 3 represents natural sepiolite powder used in step (1) in embodiment 1, modified meerschaum represents the modified meerschaum of step (1) gained in embodiment 1, sepiolite supported type nano zero valence iron represents the nanometer nulvalent iron particle of the support type of final gained in embodiment 1, nano zero valence iron represents the nanometer nulvalent iron particle of gained in comparative examples 1, blank expression does not add any material, as can be seen from Figure 3, after reaction 24h, the concentration of the nanometer nulvalent iron particle processing procedure of the support type of final gained in embodiment 1 is adopted to be that the residual rate of BDE209 in the BDE209 aqueous solution of 2mg/L is only 0.05, and adopt the natural sepiolite powder that in embodiment 1, step (1) is used, the modified meerschaum of step (1) gained in embodiment 1, in comparative examples 1, the concentration of the nanometer nulvalent iron particle processing procedure of gained is that the residual rate of BDE209 in the BDE209 aqueous solution of 2mg/L is all more than 0.6, show that the nanometer nulvalent iron particle of the support type of gained of the present invention is much better than natural sepiolite powder to the removal effect of BDE209 in water thus, modified meerschaum, nanometer nulvalent iron particle.
embodiment 2
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, and have nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads, the concentration that its preparation process is removed in step (3) is the NaBH of 0.4mol/L
4aqueous solution concentration is the KBH of 0.4mol/L
4the aqueous solution replaces, and other are all same as embodiment 1.
Adopt transmission electron microscope instrument (JEM 2011, Jeol, Japan) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, can draw, be 5-20nm at the particle diameter of the nanometer nulvalent iron particle of the area load of modified meerschaum carrier, and be about 0.01-1nm at the diameter of the nanometer nulvalent iron particle of the internal load of modified meerschaum.
embodiment 3
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, and have nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads, its preparation process specifically comprises the following steps:
(1), the preparation of modified meerschaum
The aqueous hydrochloric acid solution that mass percent concentration is 15% is added in natural sepiolite powder, then abundant mix and blend 48h at 25-30 DEG C, then it is neutral for washing to efflux with deionized deoxygenated water, then control temperature is 115 DEG C and carries out drying, then control temperature is 320 DEG C and carries out roasting, then grind, cross 160 mesh sieves, the powder of gained is modified meerschaum;
Mass percent concentration is the consumption of the aqueous hydrochloric acid solution of 15%, calculates in mass ratio, i.e. natural sepiolite powder: mass percent concentration be 15% aqueous hydrochloric acid solution be 1:5;
(2), containing the preparation of the modified meerschaum solution of iron ion
The modified meerschaum of 6g step (1) gained is joined the FeCl that 100mL concentration is 0.2mol/L
3in the aqueous solution, after fully mixing 12h under room temperature, controlling rotating speed, to be that 9000r/min carries out centrifugal to remove unnecessary iron ion, the precipitation 100ml deionized deoxygenated water obtained dissolves, then adjust pH to be 3.0 with the NaOH aqueous solution of concentration to be the HCl aqueous solution of 0.5mol/L and concentration be 0.5mol/L, obtain the modified meerschaum solution containing iron ion;
Above-mentioned modified meerschaum and concentration are the FeCl of 0.2mol/L
3the consumption of the aqueous solution, by modified meerschaum: concentration is the FeCl of 0.2mol/L
3the aqueous solution is that the ratio of 3g:50ml calculates;
(3), the preparation of nano zero-valence ferrous solution
With N
2for protection, be under the condition of 320r/min at rotating speed, is that 15ml/min adds reducing agent to step (2) gained containing controlling drop rate in the modified meerschaum solution of iron ion, after adding, continuing to control rotating speed is that 320r/min stirs 30-60min, obtains the nano zero-valence ferrous solution of black;
The NaBH of described reducing agent to be concentration be 0.9mol/L
4the aqueous solution, the consumption of reducing agent, calculates in molar ratio, the boron hydracid radical ion namely in reducing agent: be 4.5:1 containing the iron ion in the modified meerschaum solution of iron ion;
(4), the preparation of the nanometer nulvalent iron particle of support type
Nano zero-valence ferrous solution through the black of step (3) gained controls rotating speed, and to be that 9000r/min carries out centrifugal, the precipitation of gained washs 4 times with deionized deoxygenated water, straight alcohol successively, then control temperature is 65 DEG C and carries out vacuum drying, obtains the nanometer nulvalent iron particle of support type.
Adopt transmission electron microscope instrument (JEM 2011, Jeol, Japan) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, can draw, be 5-20nm at the particle diameter of the nanometer nulvalent iron particle of the area load of modified meerschaum carrier, and be about 0.01-1nm at the diameter of the nanometer nulvalent iron particle of the internal load of modified meerschaum.
embodiment 4
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, and have nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads, the concentration that its preparation process is removed in step (3) is the NaBH of 0.9mol/L
4aqueous solution concentration is the KBH of 0.9mol/L
4the aqueous solution replaces, and other are all same as embodiment 3.
Adopt transmission electron microscope instrument (JEM 2011, Jeol, Japan) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, can draw, be 5-20nm at the particle diameter of the nanometer nulvalent iron particle of the area load of modified meerschaum carrier, and be about 0.01-1nm at the diameter of the nanometer nulvalent iron particle of the internal load of modified meerschaum.
embodiment 5
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, and have nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads, its preparation process specifically comprises the following steps:
(1), the preparation of modified meerschaum
The aqueous hydrochloric acid solution that mass percent concentration is 15% is added in natural sepiolite powder, then abundant mix and blend 48h at 25-30 DEG C, then it is neutral for washing to efflux with deionized deoxygenated water, then control temperature is 125 DEG C and carries out drying, then control temperature is 330 DEG C and carries out roasting, then grind, cross 200 mesh sieves, the powder of gained is modified meerschaum;
Mass percent concentration is the consumption of the aqueous hydrochloric acid solution of 15%, calculates in mass ratio, i.e. natural sepiolite powder: mass percent concentration be 15% aqueous hydrochloric acid solution be 1:5;
(2), containing the preparation of the modified meerschaum solution of iron ion
The modified meerschaum of 6g step (1) gained is joined the FeCl that 100mL concentration is 0.3mol/L
3in the aqueous solution, under room temperature fully after mixing 12h, controlling rotating speed, to be that 10000r/min carries out centrifugal to remove unnecessary iron ion, and the precipitation obtained is with being the FeCl of 0.3mol/L with concentration
3the isopyknic deionized deoxygenated water of the aqueous solution dissolves, and is then 3.0 with the NaOH aqueous solution tune pH of concentration to be the HCl aqueous solution of 0.5mol/L and concentration be 0.5mol/L, obtains the modified meerschaum solution containing iron ion;
Above-mentioned modified meerschaum and concentration are the FeCl of 0.3mol/L
3the consumption of the aqueous solution, by modified meerschaum: concentration is the FeCl of 0.3mol/L
3the aqueous solution is that the ratio of 3g:50ml calculates;
(3), the preparation of nano zero-valence ferrous solution
With N
2for protection, be under the condition of 340r/min at rotating speed, is that 20ml/min adds reducing agent to step (2) gained containing controlling drop rate in the modified meerschaum solution of iron ion, after adding, continuing to control rotating speed is that 340r/min stirs 30-60min, obtains the nano zero-valence ferrous solution of black;
The NaBH of described reducing agent to be concentration be 1.5mol/L
4the aqueous solution, the consumption of reducing agent, calculates in molar ratio, the boron hydracid radical ion namely in reducing agent: be 5:1 containing the iron ion in the modified meerschaum solution of iron ion;
(4), the preparation of loaded nano nulvalent iron particle
Nano zero-valence ferrous solution through the black of step (3) gained controls rotating speed, and to be that 10000r/min carries out centrifugal, the precipitation of gained washs 5 times with deionized deoxygenated water, straight alcohol successively, then control temperature is 70 DEG C and carries out vacuum drying, obtains the nanometer nulvalent iron particle of support type.
Adopt transmission electron microscope instrument (JEM 2011, Jeol, Japan) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, can draw, be 5-20nm at the particle diameter of the nanometer nulvalent iron particle of the area load of modified meerschaum carrier, and be about 0.01-1nm at the diameter of the nanometer nulvalent iron particle of the internal load of modified meerschaum.
embodiment 6
A nanometer nulvalent iron particle for support type take modified meerschaum as carrier, and have nanometer nulvalent iron particle on the surface of modified meerschaum carrier and inner all loads, the concentration that its preparation process is removed in step (3) is the NaBH of 1.5mol/L
4aqueous solution concentration is the KBH of 1.5mol/L
4the aqueous solution replaces, and other are all same as embodiment 5.
Adopt transmission electron microscope instrument (JEM 2011, Jeol, Japan) nanometer nulvalent iron particle of the support type of above-mentioned gained is measured, can draw, be 5-20nm at the particle diameter of the nanometer nulvalent iron particle of the area load of modified meerschaum carrier, and be about 0.01-1nm at the diameter of the nanometer nulvalent iron particle of the internal load of modified meerschaum.
In sum, the nanometer nulvalent iron particle of a kind of support type of the present invention, take modified meerschaum as carrier, nanometer nulvalent iron particle is had on the surface of modified meerschaum carrier and inner all loads, the particle size distribution range of the nano zero-valence iron ion of surface institute load is 5-20nm, and the diameter of the nanometer nulvalent iron particle of sepiolite internal load is about 0.01-1nm; And in removal pollutant decabromodiphenyl oxide, the removal effect of nanometer nulvalent iron particle to it of support type is much better than the nano zero valence iron of sepiolite, modified meerschaum and non-load.
The above is only the citing of embodiments of the present invention; it should be pointed out that for those skilled in the art, under the prerequisite not departing from the technology of the present invention principle; can also make some improvement, these improvement also should be considered as protection scope of the present invention.