Preparation method of nano ferroferric oxide porous heavy metal adsorbing material

Abstract

The invention relates to a preparation method of a nano ferroferric oxide porous heavy metal adsorbing material. A three-dimensional microsphere template is prepared through a SiO2 microsphere, and then is fully impregnated in a Fe3O4 precursor solution, and drying, sintering and soaking are performed to obtain the nano ferroferric oxide porous heavy metal adsorbing material with controllable pore size and specific surface area. The microsphere template is fully impregnated through the precursor solution, the template is removed through heating and solvent soaking while the ferroferric oxide is produced, then a pure ferroferric oxide phase and a porous microstructure are obtained, and the high-specific surface area porous adsorbing material is further obtained; the adsorbing material is strong in adsorbing capacity; the method can control the mespore size to be 2-50 nm, a large pore to be more than 50 nm, and the scope of the specific surface area to be 100-1600 m<2> / g; the porous adsorbing material has a strong adsorbing capacity for the heavy metal ions like Pb, Cr, Cd, As, Ni and Cu, and the preparation method has the advantages of simple operation, controllable structure, low preparation cost and broad market prospect.

Description

technical field [0001] The invention relates to the technical field of heavy metal sewage treatment, in particular to a preparation method of a nanometer iron ferric oxide porous heavy metal adsorption material. Background technique [0002] With the development of the economy, a large amount of industrial waste water is discharged randomly, causing serious pollution of heavy metal ions in rivers and soil, which is extremely harmful to people's health. Unlike other pollution, heavy metal pollution has the following characteristics: 1. Long-term; 2. 1. Accumulation, gradually accumulating from bottom to top in the food chain, 3. Irreversibility, 4. Latency, it is difficult to degrade in the environment, and it is difficult to remove heavy metals in organisms, which will cause persistent damage to the body. 5. Trace amount Can produce significant toxic effects. [0003] Because heavy metal pollution has the characteristics of concealment, long-term, and cumulative nature of e...

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Problems solved by technology

[0005] 1. Porous carbon, porous carbon refers to a material with carbon as the skeleton and a well-developed pore structure, which is widely used in the field of wastewater and air treatment, including activated carbon, activated carbon fiber, doped and new polymer-based carbon and mesoporous Carbon, etc., activated carbon is the most representative, which is a non-polar porous material that can adsorb non-polar or weakly polar organic matter. Due to the micropores of the huge specific surface area, the activated carbon fiber has better adsorption performance than Activated carbon can absorb organic gases, nitrogen oxides, amine compounds, adsorb and catalyze ozone and enrich microorganisms. However, the synthesis of porous carbon is relatively difficult and is not suitable for large-scale production. At present, activated carbon is used in a large amount, but activated carbon exists Disadvantages such as short service life, poor quality, low output, difficult regeneration and high loss rate;

[0006] 2. Silica gel, silica gel is a porous solid silica material with a large specific surface area. It is the product of silicic acid dehydration. It is mainly used for drying and can be chelated with specific functional groups to prepare heavy metal ion adsorbents. Silica gel is used The solid phase carrier used as an adsorbent is mainly due to its stable chemical properties, insoluble in water and many solvents, non-toxic and tasteless; the specific surface area and pore structure are relatively easy to control, which can meet the adsorption of different substances, good mechanical strength, and difficult material properties. Change, the surface has silanol groups, which are easy to bond with functional groups, and prepare adsorbents for different needs. However, once silica gel absorbs water or other organic substances, its adsorption capacity will decrease, and the recyclability is poor. When drying, if the temperature is too high, it will cause structural changes and affect its adsorption performance.

[0007] 3. Activated alumina, which is a solid material with large specific surface area, highly dispersed and porous, is mainly obtained by impregnating active components and calcining at high temperature. It has high mechanical strength, is non-toxic and tasteless, has good insolubility, and can absorb Moisture and specific gases (eg H2S), Cr 6+ , P and As, especially for F has a strong adsorption, but it is greatly affected by pH, and the adsorption amount will be different under different water quality conditions, the cost of F desorption is too high, which is not conducive to circulation regeneration

[0008] 4. Molecular sieve, molecular sieve is a kind of aluminosilicate compound with a large number of uniform micropores, whose pore size is equivalent to the molecular diameter, so it can absorb molecules smaller than the pore size and keep the larger ones out. It is made of silicon Oxygen and aluminum oxide tetrahedra form the basic skeleton structure, and there are metal cations in the lattice to achieve the purpose of charge balance. Molecular sieves are used in the purification of waste water and waste due to their cheapness, renewability, and wide application. There are 3A, 4A, 5A, 10X, 13X, 13XAPG, oxygen-enriched molecular sieves and other types to meet different purposes such as drying, desulfurization and decarbonization, etc. However, their cycle stability and durability are poor, and when purifying the air, water The presence of will affect the adsorption of pollutants, resulting in a decrease in the adsorption capacity

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