Ferrihydrite-graphene composite and application thereof

Abstract

The invention discloses a ferrihydrite-graphene composite.A preparation method of the ferrihydrite-graphene composite comprises the following steps that 1, graphene oxide is taken and added to distilled water with 5-20 times of weight, and ultrasonic dissolving is carried out to form sol; 2, trivalent molysite is added into the sol, the mass of ferric ions in the sol accounts for 5% to 40% of the mass of solid solution matter, stirring is carried out, the pH of the sol is adjusted to range from 7 to 8 with metal aqueous alkali, and stirring continues to be carried out for 10 min to 60 min; 3, centrifugation is carried out, and sediment is separated and washed 2-5 times with deionized water; 4, the sediment is dried at the temperature of 40 DEG C to 50 DEG C, and smashing is carried out.The ferrihydrite-graphene composite can adsorb inorganic phosphorus and organic phosphorus in a polluted water body at the same time, the adsorption capacity is large, and compared with other water body dephosphorization methods, the ferrihydrite-graphene composite has the advantages of being easy and convenient to operate, low in cost, easy to control, easy to recycle, environmentally friendly and the like.

Description

technical field

[0001] The invention belongs to the technical field of water body organic pollutant treatment, and in particular relates to a ferrihydrite-graphene composite material and its application as an adsorbent in water body dephosphorization. Background technique

[0002] As a large amount of phosphorus-containing wastewater is discharged into the water body without treatment or improper treatment, the phosphorus content in the water body far exceeds the discharge standard, resulting in increasingly serious eutrophication of the water body, threatening the survival of aquatic organisms and the safety of drinking water. At present, there are mainly biological methods, chemical precipitation methods, artificial wetland methods, ion exchange methods, and adsorption methods to remove phosphorus from water bodies. The biological method and chemical precipitation method will produce a large amount of phosphorus-containing excess sludge, which increases the cost of treatme...

Examples

Embodiment 1

[0018] Preparation of ferrihydrite-graphene composite:

[0019] 1) Take graphene oxide flakes with a diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm, add 15 times the weight of distilled water, and ultrasonically dissolve to form a sol;

[0020] 2) Add ferric nitrate to the sol so that the mass of ferric ions in the sol accounts for 20% of the solid solution mass, stir, adjust the pH of the sol to 7.5 with 1mol / L KOH solution, and continue stirring for 30 min;

[0021] 3) Centrifuge, separate the precipitate and wash 3 times with deionized water;

[0022] 4) Dry the precipitate at 45°C and pulverize it.

[0023] After testing, the removal rate of inorganic phosphorus is 85%, and the removal rate of organic phosphorus is 95%.

Embodiment 2

[0025] Preparation of ferrihydrite-graphene composite:

[0026] 1) Take graphene oxide flakes with a diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm, add 5 times the weight of distilled water, and ultrasonically dissolve to form a sol;

[0027] 2) Add ferric chloride to the sol so that the mass of ferric ions in the sol accounts for 10% of the solid solution mass, stir, adjust the pH of the sol to 8 with 0.5mol / L NaOH solution, and continue stirring for 15 minutes;

[0028] 3) Centrifuge, separate the precipitate and wash twice with deionized water;

[0029] 4) Dry the precipitate at 40°C and pulverize it.

[0030] After testing, the removal rate of inorganic phosphorus is 78%, and the removal rate of organic phosphorus is 86%.

Embodiment 3

[0032] Preparation of ferrihydrite-graphene composite:

[0033] 1) Take powdered graphene oxide with a particle size of 0.5-5 μm, add 20 times the weight of distilled water, and ultrasonically dissolve to form a sol;

[0034] 2) Add ferric sulfate to the sol so that the mass of ferric ions in the sol accounts for 40% of the solid solution mass, stir, adjust the pH of the sol to 7 with 2mol / L KOH solution, and continue stirring for 60 min;

[0035] 3) Centrifuge, separate the precipitate and wash 5 times with deionized water;

[0036] 4) Dry the precipitate at 50°C and pulverize it.

[0037] After testing, the removal rate of inorganic phosphorus is 75%, and the removal rate of organic phosphorus is 85%.

technical field

[0001] The invention belongs to the technical field of water body organic pollutant treatment, and in particular relates to a ferrihydrite-graphene composite material and its application as an adsorbent in water body dephosphorization. Background technique

[0002] As a large amount of phosphorus-containing wastewater is discharged into the water body without treatment or improper treatment, the phosphorus content in the water body far exceeds the discharge standard, resulting in increasingly serious eutrophication of the water body, threatening the survival of aquatic organisms and the safety of drinking water. At present, there are mainly biological methods, chemical precipitation methods, artificial wetland methods, ion exchange methods, and adsorption methods to remove phosphorus from water bodies. The biological method and chemical precipitation method will produce a large amount of phosphorus-containing excess sludge, which increases the cost of treatme...

Examples

Embodiment 1

[0018] Preparation of ferrihydrite-graphene composite:

[0019] 1) Take graphene oxide flakes with a diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm, add 15 times the weight of distilled water, and ultrasonically dissolve to form a sol;

[0020] 2) Add ferric nitrate to the sol so that the mass of ferric ions in the sol accounts for 20% of the solid solution mass, stir, adjust the pH of the sol to 7.5 with 1mol / L KOH solution, and continue stirring for 30 min;

[0021] 3) Centrifuge, separate the precipitate and wash 3 times with deionized water;

[0022] 4) Dry the precipitate at 45°C and pulverize it.

[0023] After testing, the removal rate of inorganic phosphorus is 85%, and the removal rate of organic phosphorus is 95%.

Embodiment 2

[0025] Preparation of ferrihydrite-graphene composite:

[0026] 1) Take graphene oxide flakes with a diameter of 0.5-5 μm and a thickness of 0.8-1.2 nm, add 5 times the weight of distilled water, and ultrasonically dissolve to form a sol;

[0027] 2) Add ferric chloride to the sol so that the mass of ferric ions in the sol accounts for 10% of the solid solution mass, stir, adjust the pH of the sol to 8 with 0.5mol / L NaOH solution, and continue stirring for 15 minutes;

[0028] 3) Centrifuge, separate the precipitate and wash twice with deionized water;

[0029] 4) Dry the precipitate at 40°C and pulverize it.

[0030] After testing, the removal rate of inorganic phosphorus is 78%, and the removal rate of organic phosphorus is 86%.

Embodiment 3

[0032] Preparation of ferrihydrite-graphene composite:

[0033] 1) Take powdered graphene oxide with a particle size of 0.5-5 μm, add 20 times the weight of distilled water, and ultrasonically dissolve to form a sol;

[0034] 2) Add ferric sulfate to the sol so that the mass of ferric ions in the sol accounts for 40% of the solid solution mass, stir, adjust the pH of the sol to 7 with 2mol / L KOH solution, and continue stirring for 60 min;

[0035] 3) Centrifuge, separate the precipitate and wash 5 times with deionized water;

[0036] 4) Dry the precipitate at 50°C and pulverize it.

[0037] After testing, the removal rate of inorganic phosphorus is 75%, and the removal rate of organic phosphorus is 85%.