CN110606538A - Method for removing pollutants based on efficient reduction of borated zero-valent iron - Google Patents
Method for removing pollutants based on efficient reduction of borated zero-valent iron Download PDFInfo
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- CN110606538A CN110606538A CN201910692690.4A CN201910692690A CN110606538A CN 110606538 A CN110606538 A CN 110606538A CN 201910692690 A CN201910692690 A CN 201910692690A CN 110606538 A CN110606538 A CN 110606538A
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- valent iron
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/70—Treatment of water, waste water, or sewage by reduction
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/20—Heavy metals or heavy metal compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
- C02F2101/36—Organic compounds containing halogen
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
- C02F2101/38—Organic compounds containing nitrogen
Abstract
The invention relates to a method for removing pollutants based on borated zero-valent iron efficient reduction. Adding borated zero-valent iron into a pollutant solution to remove pollutants; the borated zero-valent iron is prepared by reacting-OB (OH) with partial hydroxyl groups on the surface of zero-valent iron2Group-substituted zero-valent iron. The method for removing pollutants by efficient reduction based on borated zero-valent iron provided by the invention has better reduction removal capability on different heavy metal ions, organic pollutants and the like. The method for preparing the borated zero-valent iron by the borated modified zero-valent iron ball milling method is simple and easy to operate.
Description
Technical Field
The invention belongs to the field of environmental chemistry, and particularly relates to control and restoration of heavy metal ions and chlorine (nitro) containing organic matters in a water body, which is suitable for treatment of wastewater in the fields of printing and dyeing, industry and the like.
Background
In recent years, heavy metal ions and chlorine (nitro) containing organic matters are commonly reported to pollute the human body, and the human health is seriously harmed due to the characteristics of easy accumulation, irreversibility, high toxicity, slow metabolism, easy enrichment and the like. The zero-valent iron has low price and is environment-friendly, so that the reduction and fixation of heavy metals and the dechlorination/denitrogenation of chlorine/nitro compounds can be realized, and the method is further widely applied to the treatment of polluted underground water.
However, the surface of the zero-valent iron is easily oxidized, and the surface is covered with a layer of iron oxide, and the iron oxide can block the release of electrons in the zero-valent iron, thereby causing the activity of the zero-valent iron to be reduced. Even if the activity of the zero-valent iron is improved by removing (partially) the shell layer on the surface of the zero-valent iron by adopting acid washing, reducing agent reduction, ultrasonic stripping and other modes, the iron oxide is inevitably formed again in the reaction process, so the activity of the zero-valent iron cannot be improved fundamentally. In addition, the hydroxyl groups on the surface of the oxide layer can affect the adsorption of the pollutants, because the hydroxyl groups have hydrophilicity and can reduce the adsorption capacity of the pollutants.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for efficiently removing pollutants based on borated zero-valent iron by changing the surface functional group of the zero-valent iron to improve the activity of removing the pollutants.
The technical scheme adopted by the invention for solving the problems is as follows:
borated zero-valent iron in which the hydroxyl groups on the surface of zero-valent iron are substituted by-OB (OH)2Group-substituted zero-valent iron.
A borated zero-valent iron is used for removing pollutants by high-efficiency reduction, the borated zero-valent iron is added into an aqueous solution of the pollutants to carry out the activity removal of the pollutants; the borated zero-valent iron is obtained by reacting-OB (OH) with hydroxyl groups on the surface of zero-valent iron2Group-substituted zero-valent iron.
According to the scheme, the borated zero-valent iron is prepared by boric acid and zero-valent iron through a ball milling method.
According to the scheme, the molar ratio of the boric acid added in the ball milling process is 0.05-10.0 percent of zero-valent iron, and the optimal molar ratio is 1-8 percent.
According to the scheme, the ball milling time is as follows: 2-10h, and the rotation speed is 200-. After ball milling, boric acid and zero-valent iron are washed by alcohol and dried in vacuum.
According to the scheme, the zero-valent iron is micron-sized zero-valent iron.
According to the scheme, the purity of the zero-valent iron reaches 90%, and the purity of the boric acid is above the industrial level.
According to the scheme, the using amount of the borated zero-valent iron is 1-5 g/L.
According to the scheme, the concentration of the pollutants is 2-10ppm, the reaction temperature is 0-50 ℃, and the reaction pH is 3-10.
In the above scheme, the contaminants include, but are not limited to, chromium, nickel, lead, 4-chlorophenol, nitrobenzene, and the like.
According to the scheme, the pollutant removing process adopts a shaking table oscillation mode.
The technical principle of the invention is as follows:
the iron oxide surface on the zero-valent iron surface is covered with a layer of hydroxyl, which is not beneficial to adsorbing and removing pollutants, and the activity of the zero-valent iron is reduced. According to the invention, environment-friendly boric acid is selected as a modifier for the surface of the zero-valent iron, and the borated zero-valent iron is prepared by adopting a simple ball milling method. From the infrared characterization (fig. 1a), the infrared of borated zero valent iron presents new peaks relative to the peak of the boronic acid molecule: 1335, 1000, and 925cm-1Respectively represent a B-O asymmetric expansion joint, a B-O-H in-plane expansion vibration peak and a B-O vibration peak. And at 1150, 1130cm-1The peak at (b) is increased, indicating that the coordination environment around the boronic acid is changed, thereby decreasing the symmetry of the boronic acid. Boric acid reacts with hydroxyl groups on the iron surface, loses one molecule of water, and is bonded to the zero-valent iron surface in a three-coordinate form (fig. 1 b). The boration can accelerate the corrosion of the zero-valent iron and promote the outward transfer of electrons of the zero-valent iron (figure 2), thereby promoting the removal of the pollutants.
The invention has the advantages that:
1. the method for preparing the borated zero-valent iron by the borated modified zero-valent iron ball milling method is simple and easy to operate.
2. The zero-valent iron has low price, low boric acid consumption and low cost, and can be widely applied to the treatment of actual pollutants.
3. The borated modified zero-valent iron provided by the invention has better reduction removal capability on different heavy metal ions, organic pollutants and the like.
Drawings
FIG. 1 is an infrared diagram (a) and a mechanism diagram (b) of ball-milling borated zero-valent iron;
FIG. 2 Tafel plot of borated zero valent iron;
FIG. 3 is a graph showing the effects of ball milling for preparing borated zero-valent iron and treating hexavalent chromium in polluted water in example 1;
FIG. 4 is a graph showing the effects of ball milling for preparing borated zero-valent iron and treating nickel in a polluted water body in example 2;
FIG. 5 is a diagram showing the effects of ball milling for preparing borated zero-valent iron and treating lead in polluted water in example 3;
FIG. 6 is a graph showing the effects of ball milling for preparing borated zero-valent iron and treating 4-chlorophenol in polluted water in example 4;
FIG. 7 is a graph showing the effects of ball milling for preparing borated zero-valent iron and treating nitrobenzene in polluted water in example 5.
Detailed Description
The following detailed description of the present invention is provided by way of specific embodiments, which are provided for illustration purposes and are not intended to limit the invention.
Example 1 ball milling for preparing borated zero-valent iron and treating an effect graph of hexavalent chromium in polluted water;
5.6g of zero-valent iron (the particle size is 150 mu m) and a certain amount of boric acid are put into a ball milling tank, the rotating speed is 550r/min, the ball milling time is 2h, and then the sample is washed by alcohol and dried in vacuum to obtain borated zero-valent iron x% B-ZVI (x% is the molar ratio of the boric acid to the zero-valent iron). 30mL of hexavalent chromium solution with the concentration of 2mg/L is used for simulating chromium wastewater, the pH of the solution is 7, the temperature is 25 ℃, 0.1g of B-ZVI sample is added, the solution is put into a shaking table with the rotating speed of 100r/min, and the concentration of hexavalent chromium in the solution is periodically tested, and the result is shown in figure 3. The borated zero-valent iron has stronger capability of removing hexavalent chromium than non-borated zero-valent iron, and the chromium removal rate tends to increase first and then decrease with the increase of the boration ratio. The hexavalent chromium is completely removed in 40min by the optimal boric acid ratio sample 1% B-ZVI, and the non-borated zero-valent iron is only removed by 10% in 90min, so that the borated zero-valent iron can greatly improve the capability of reducing and removing the hexavalent chromium.
Example 2 ball milling preparation of borated zero-valent iron and treatment of nickel effect diagram in polluted water;
5.6g (the particle size is 80 mu m) of zero-valent iron and 0.250g of boric acid are put into a ball milling tank, the rotating speed is 200r/min, and the ball milling time is 10h, so that 4.0% B-ZVI of borated zero-valent iron is obtained. The nickel concentration of the solution was measured spectrophotometrically by using a solution containing nickel at a concentration of 10mg/L and a volume of 100mL, the pH of the solution was 4, the temperature was 50 ℃, 0.5g of the B-ZVI sample was added, and the solution was placed in a shaker at a rotation speed of 200r/min, and the results are shown in FIG. 4. The non-borated zero-valent iron is only removed by 60 percent within 90min, while the borated zero-valent iron almost completely removes nickel within 40min, so the borated zero-valent iron can improve the removal of nickel.
Example 3 ball milling preparation of borated zero-valent iron and treatment of lead effect diagram in polluted water;
5.6g (the particle size is 150 mu m) of zero-valent iron and 0.5g of boric acid (the molar ratio of the boric acid to the zero-valent iron is 8.0%) are put into a ball milling tank, the rotating speed is 800r/min, and the ball milling time is 4h, so that borated 8.0% B-ZVI of the zero-valent iron is obtained. The concentration of 5mg/L lead wastewater with a volume of 50mL, the pH of the solution at 10 ℃ and the temperature at 10 ℃, 0.2g of B-ZVI sample is added, the mixture is put into a shaking table with the rotation speed of 250r/min, and the lead concentration in the solution is measured by an atomic adsorption method, and the result is shown in FIG. 5. The lead is removed only by 20% in 90min by the non-borated zero-valent iron, and the lead is removed by the borated zero-valent iron in 30min, so that the lead removal by the borated zero-valent iron can be improved.
Example 4 ball milling preparation of borated zero-valent iron and treatment of the effect graph of 4-chlorophenol in polluted water;
5.6g of zero-valent iron with the particle size of 40 mu m and 0.125g of boric acid (the molar ratio of the boric acid to the zero-valent iron is 2.0%) are put into a ball milling tank, the rotating speed is 550r/min, and the ball milling time is 2 hours, so that borated zero-valent iron 2.0% B-ZVI is obtained. The concentration of 4-chlorophenol solution with a volume of 50mL and a concentration of 10mg/L, the pH of the solution is 8, the temperature is 0 ℃, 0.1g of B-ZVI sample is added, the mixture is put into a shaking table with a rotating speed of 50r/min, and the concentration of 4-chlorophenol in the solution is periodically tested, and the result is shown in figure 6. The non-borated zero-valent iron can remove 20% of 4-chlorophenol within 120min, and the borated zero-valent iron can remove the 4-chlorophenol within 120min, so that the borated zero-valent iron can improve the removal of the 4-chlorophenol.
Example 5 ball milling preparation of borated zero-valent iron and treatment of nitrobenzene effect diagram in polluted water;
5.6g of zero-valent iron with the particle size of 80 mu m and 0.250g of boric acid (the molar ratio of the boric acid to the zero-valent iron is 4.0%) are put into a ball milling tank, the rotating speed is 500r/min, and the ball milling time is 6h, so that 4.0% B-ZVI of the borated zero-valent iron is obtained. Nitrobenzene solution with concentration of 10mg/L and volume of 50mL, solution pH of 3, temperature of 30 ℃, adding 0.2g of B-ZVI sample, putting into a shaker with rotation speed of 200r/min, and periodically testing the concentration of nitrobenzene, wherein the result is shown in FIG. 7. 40% of nitrobenzene is removed by non-borated zero-valent iron within 90min, and almost all nitrobenzene is removed by borated zero-valent iron within 60min, so that the removal of p-nitrobenzene can be improved by borated zero-valent iron.
Claims (10)
1. A method for removing pollutants by efficiently reducing borated zero-valent iron is characterized by comprising the following steps: adding borated zero-valent iron into a pollutant solution to remove pollutants; the borated zero-valent iron is prepared by reacting-OB (OH) with partial hydroxyl groups on the surface of zero-valent iron2Group-substituted zero-valent iron.
2. The method of claim 1, wherein: the borated zero-valent iron is prepared by boric acid and zero-valent iron through a ball milling method; the boric acid added in the ball milling process accounts for 0.05-10.0% of zero-valent iron according to molar ratio.
3. The method of claim 2, wherein: the boric acid added in the ball milling preparation process accounts for 1 to 8 percent of zero-valent iron according to molar ratio.
4. The method of claim 2, wherein: the ball milling time is 2-10 h.
5. The method of claim 2, wherein: the rotation speed is 200 and 800 r/min.
6. The method of claim 1, wherein: the zero-valent iron is micron-sized zero-valent iron.
7. The method of claim 1, wherein: the using amount of the borated zero-valent iron is 1-5 g/L.
8. The method of claim 1, wherein: the concentration of the pollutants is 2-10ppm, the reaction temperature is 0-50 ℃, and the reaction pH is 3-10.
9. The method of claim 1, wherein: such contaminants include, but are not limited to, chromium, nickel, lead, 4-chlorophenol, nitrobenzene; the pollutant removing process adopts a shaking table oscillation mode.
10. Borated zero-valent iron in which the hydroxyl groups on the surface of zero-valent iron are substituted by-OB (OH)2Group-substituted zero-valent iron.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112139508A (en) * | 2020-09-23 | 2020-12-29 | 中国科学院地理科学与资源研究所 | Amphoteric surface micron zero-valent iron, and preparation method and application thereof |
| CN112320919A (en) * | 2020-10-16 | 2021-02-05 | 中国环境科学研究院 | Water body restoration method based on zero-valent iron silicide activated persulfate |
| CN113522952A (en) * | 2021-06-16 | 2021-10-22 | 华南师范大学 | Zero-valent iron composite material and preparation method and application thereof |
| CN114291992A (en) * | 2021-12-29 | 2022-04-08 | 华中师范大学 | Preparation combination for removing municipal sludge antibiotic resistance genes and application |
| US20220118516A1 (en) * | 2020-10-16 | 2022-04-21 | Chinese Research Academy Of Environmental Sciences | Silicified modified zero-valent iron and its preparation method and application |
| CN115090237A (en) * | 2022-05-18 | 2022-09-23 | 上海交通大学 | Method for converting zero-valent iron into waste plastic through photo-thermal conversion into high-value-added fuel and environment-repairing material |
| CN115403124A (en) * | 2022-09-09 | 2022-11-29 | 浙江工业大学绍兴研究院 | Method for efficiently removing heavy metal pollutants by ball milling of sargassum acidized zero-valent iron composite material |
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112139508A (en) * | 2020-09-23 | 2020-12-29 | 中国科学院地理科学与资源研究所 | Amphoteric surface micron zero-valent iron, and preparation method and application thereof |
| CN112320919A (en) * | 2020-10-16 | 2021-02-05 | 中国环境科学研究院 | Water body restoration method based on zero-valent iron silicide activated persulfate |
| CN112320919B (en) * | 2020-10-16 | 2021-11-16 | 中国环境科学研究院 | Water body restoration method based on zero-valent iron silicide activated persulfate |
| US20220118516A1 (en) * | 2020-10-16 | 2022-04-21 | Chinese Research Academy Of Environmental Sciences | Silicified modified zero-valent iron and its preparation method and application |
| US11850664B2 (en) * | 2020-10-16 | 2023-12-26 | Chinese Research Academy Of Environmental Sciences | Silicified modified zero-valent iron and its preparation method and application |
| CN113522952A (en) * | 2021-06-16 | 2021-10-22 | 华南师范大学 | Zero-valent iron composite material and preparation method and application thereof |
| CN113522952B (en) * | 2021-06-16 | 2023-02-28 | 华南师范大学 | Zero-valent iron composite material and preparation method and application thereof |
| CN114291992A (en) * | 2021-12-29 | 2022-04-08 | 华中师范大学 | Preparation combination for removing municipal sludge antibiotic resistance genes and application |
| CN114291992B (en) * | 2021-12-29 | 2022-07-19 | 华中师范大学 | Preparation combination for removing municipal sludge antibiotic resistance genes and application |
| CN115090237A (en) * | 2022-05-18 | 2022-09-23 | 上海交通大学 | Method for converting zero-valent iron into waste plastic through photo-thermal conversion into high-value-added fuel and environment-repairing material |
| CN115403124A (en) * | 2022-09-09 | 2022-11-29 | 浙江工业大学绍兴研究院 | Method for efficiently removing heavy metal pollutants by ball milling of sargassum acidized zero-valent iron composite material |
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