阅读说明：本技术 Fenton反应亚铁缓释颗粒 (Fenton reaction ferrous iron slow release granule ) 是由 高卫民 程寒飞 詹茂华 陈志刚 于 2019-05-07 设计创作，主要内容包括：本发明公开了一种Fenton反应亚铁缓释颗粒。它是由无机粘结剂、有机粘结剂、水溶性亚铁盐、矿物材料经二次造粒而成,其制备工艺是首先矿物材料、水溶性亚铁盐和有机粘结剂混合,一次造粒,真空干燥；而后再与无机粘结剂混合,二次造粒。制得的亚铁盐颗粒可以持续缓慢释放亚铁离子,与H<Sub>2</Sub>O<Sub>2</Sub>反应,生成羟基自由基,分解有机污染物。该亚铁缓释颗粒具有结构性好,强度高,亚铁离子缓释效果好等特点,可大大提高Fenton反应生产羟基自由基的使用效率,从而提高污染物降解效率。而且更换方便,使用后的多孔结构颗粒,又可以作为微生物良好的载体。(The invention discloses a Fenton reaction ferrous iron sustained-release granule. The mineral material is prepared by mixing the mineral material, the water-soluble ferrous salt and the organic binder, granulating for the first time and drying in vacuum; then mixing with inorganic binder, and granulating twice. The prepared ferrous salt particles can continuously and slowly release ferrous ions and H 2 O 2 And reacting to generate hydroxyl free radicals, and decomposing organic pollutants. The ferrous sustained-release particles have the characteristics of good structure, high strength, good ferrous ion sustained-release effect and the like, and can greatly improve the use efficiency of hydroxyl free radicals produced by Fenton reaction, thereby improving the pollutant degradation efficiency. And the replacement is convenient, and the used porous structure particles can also be used as good carriers of microorganisms.)

1. The Fenton reaction ferrous iron slow-release particle is characterized by being prepared by carrying out secondary granulation on water-soluble ferrous salt, a mineral material, an organic binder and an inorganic binder, and the preparation method comprises the following steps of:

(1) fully mixing water-soluble ferrous salt and mineral materials;

(2) adding an organic binder and water into the mixture obtained in the step (1), fully and uniformly stirring to obtain a mixture A,

and carrying out primary granulation;

(3) carrying out vacuum drying on the granules subjected to primary granulation to obtain primary granules;

(4) fully and uniformly stirring the primary granules, an inorganic binder and water to obtain a mixture B, and performing secondary granulation;

(5) and (4) carrying out vacuum drying on the granules subjected to secondary granulation.

2. The Fenton reactive ferrous iron slow-release particle as claimed in claim 1, wherein 80-100 parts by weight of water-soluble ferrous salt, 10-50 parts by weight of mineral material, 1-10 parts by weight of organic binder, 10-50 parts by weight of inorganic binder and 5-30 parts by weight of water.

3. The Fenton reactive ferrous iron slow-release particle as claimed in claim 1, wherein the water-soluble ferrous salt is one or a mixture of more than two of ferric chloride, ferrous sulfate, ferrous nitrate and ferrous ammonium sulfate, and the particle size of the ferrous salt is 0.01-5 mm.

4. The Fenton reactive ferrous iron slow-release granule as claimed in claim 1, wherein the mineral material is one or more of zeolite, attapulgite clay, diatomite, sepiolite, kaolin, montmorillonite and dolomite.

5. The Fenton reactive ferrous iron slow-release particle and the manufacturing method thereof as claimed in claim 1, wherein the organic binder is one or more than two of carboxymethyl cellulose, sodium alginate and sesbania gum.

6. The Fenton reactive ferrous iron sustained release granule according to claim 1, wherein the size of the primary granules in steps (2) and (3) is 0.1-10 mm.

7. The Fenton reactive ferrous iron slow-release granule as claimed in claim 1, wherein the inorganic binder is one or more of cement, water glass, gypsum and lime.

8. The Fenton reactive ferrous iron slow-release granule as claimed in claim 1, wherein the size of the Fenton reactive ferrous iron slow-release granule in steps (4) and (5) is 1-100mm, Fe²⁺The release rate is 0.01-5 mmol/L.min.

9. The Fenton reaction ferrous iron slow-release granule as claimed in claim 1, wherein the vacuum degree of vacuum drying in step (3) and step (5) is less than 0.01MPa, the drying temperature is from room temperature to 100 ℃, and the drying time is 1-24 h.

Technical Field

The invention belongs to the field of water pollution treatment, and relates to Fenton reaction ferrous iron sustained-release particles.

Background

The Fenton reagent is Fe²⁺And H₂O₂The mixture of (1), having a strong oxidizing property, was discovered by the chemist fenton hj in 1894. The principle is H₂O₂In Fe²⁺With catalysis of (3), to generate hydroxyl radicals fromFrom the group (. OH), OH is a very strong oxidizing agent with a standard redox potential of 2.8eV and an oxidizing power next to F (standard redox potential of 3.08eV), a second strong oxidizing agent is known. OH is a broad-spectrum oxidant, has no selectivity, and can almost react with substances in water. There are three basic reaction pathways for the reaction of OH with organic substances, namely, hydroxyl group addition reaction, hydrogen abstraction reaction of hydroxyl group, and electron transfer reaction of hydroxyl group. Hydroxyl addition reaction, i.e., OH addition to an unsaturated C-C bond; hydrogen abstraction reaction of hydroxyl, namely OH breaks C-H bond and abstracts H to form water molecule; electron transfer reaction of hydroxyl group, i.e. OH from easily oxidizable inorganic ion to an electron to form hydroxyl OH^-. The specific reaction pathway is mainly determined by the reaction of OH with the substance to be reacted. In general, the addition reaction is faster than the hydrogen abstraction reaction, and the electron transfer reaction usually occurs between OH and an inorganic substance.

Until 1970, along with the increasingly intensive research on environmental protection, the existence of refractory organic matters in sewage becomes a headache problem and is also a serious difficulty in the research of water pollution control technology. Particularly, with the rapid development of petrochemical industry, medicine, pesticide, dye and other industries, the discharge of wastewater containing various biodegradable organic pollutants is increased correspondingly, the quantity and types of the biodegradable organic pollutants in the wastewater are increased day by day, the harm is increasingly serious, and the problem becomes a focus of water pollution control. Of the methods, the Fenton treatment technology is more and more widely concerned.

OH generated by Fenton reaction is a spectral oxidant, and the OH reacts with medium and macromolecular organic matters quickly and approaches the diffusion control limit. However, OH and small molecular organic matters react slowly, a large amount of OH is formed instantly in the common Fenton reaction, and other reactions are not ready to react with the organic matters to inactivate, so that the Fenton reaction degradation efficiency is greatly reduced.

In recent years, although a great deal of research is carried out on the aspects of improving the Fenton reaction process and treating refractory organic wastewater by adopting the light/electricity synergistic Fenton reaction, the problems of low reaction efficiency of OH and organic pollutants, large sludge production and the use amount of Fenton reagents far larger than a theoretical value are not solved due to the reasons of complex process, high treatment cost, non-ideal actual effect and the like.

Disclosure of Invention

Aiming at the problems, the invention aims to provide the Fenton reaction ferrous iron sustained-release particles which are simple in preparation process and low in cost.

In order to achieve the purpose, the invention relates to a Fenton reaction ferrous iron slow-release particle, which is prepared by carrying out secondary granulation on water-soluble ferrous salt, a mineral material, an organic binder and an inorganic binder, and the preparation method comprises the following steps:

(1) fully mixing water-soluble ferrous salt and mineral materials;

(2) adding an organic binder and water into the mixture obtained in the step (1), fully and uniformly stirring to obtain a mixture A, and carrying out primary granulation;

(3) carrying out vacuum drying on the granules subjected to primary granulation to obtain primary granules;

(4) fully and uniformly stirring the primary granules, an inorganic binder and water to obtain a mixture B, and performing secondary granulation;

(5) and (4) carrying out vacuum drying on the granules subjected to secondary granulation.

Further, 80-100 parts of water-soluble ferrous salt, 10-50 parts of mineral material, 1-10 parts of organic binder, 10-50 parts of inorganic binder and 5-30 parts of water.

Further, the water-soluble ferrous salt is one or a mixture of more than two of ferrous chloride, ferrous sulfate, ferrous nitrate and ferrous ammonium sulfate, and the particle size of the ferrous salt is 0.01-5 mm.

Further, the mineral material is one or more of zeolite, attapulgite clay, diatomite, sepiolite, kaolin, montmorillonite and dolomite, and is in powder form, and the particle size is 200-80 meshes.

Furthermore, the organic binder is one or a mixture of more than two of carboxymethyl cellulose, sodium alginate and sesbania gum, and is in the form of powder with the particle size of 200-80 meshes.

Further, the organic bonding and the water in the step (2) can be uniformly mixed in advance and then stirred and mixed in the mixture in the step (1), the organic bonding and the water can be simultaneously added into the mixture in the step (1) to be stirred and mixed, or the organic bonding and the water can be alternately added into the mixture in the step (1) to be stirred and mixed.

Further, the particle size of the primary granules in the steps (2) and (3) is 0.1 to 10 mm.

Further, the inorganic binder is one or a mixture of more than two of cement, water glass, gypsum and lime.

Further, ferrous slow release particles Fe²⁺The release rate is 0.01-5 mmol/L.min, preferably 0.05-4 mmol/L.min, more preferably 0.1-3 mmol/L.min, and the release rate is less than 0.01 mmol/L.min, such that Fe²⁺Slow release, prolonged required residence time, increased reaction apparatus, release speed greater than 5mmol/L min, and Fe²⁺The releasing is too fast, the situation that excessive OH is generated instantly occurs, OH is inactivated before reacting with organic pollutants, and the efficiency of degrading organic matters by OH is reduced.

Further, the vacuum degree of vacuum drying in the step (3) and the step (5) is less than 0.01MPa, the drying temperature is between room temperature and 100 ℃, and the drying time is 1-24 h.

The Fenton reaction ferrous iron slow-release particle prepared by the invention is prepared by carrying out secondary granulation on water-soluble ferrous salt, mineral materials, organic binder and inorganic binder, has the characteristics of good particle structure, high strength, excellent ferrous ion slow-release effect and the like, and can continuously release ferrous ions and H into a water body₂O₂The Fenton reaction is carried out to generate OH, the OH is continuously released, sufficient reaction time is provided for organic pollutants, the problem that a large amount of OH is generated instantly and is inactivated after reacting with organic matters is avoided, and the effect of degrading the organic matters by the OH is improved. The porous particles which release the ferrite can be conveniently recovered and can be used as a good carrier of microorganisms. The Fenton reaction ferrous iron sustained-release granules have simple preparation process and low cost, and are suitable for large-scale production and application.

The invention has the beneficial effects that:

1. the Fenton reaction ferrous iron slow-release particles prepared by the method are prepared by secondary granulation, and have the characteristics of good structure, high strength, excellent ferrous ion slow-release effect and the like;

2. the Fenton reaction ferrous iron slow-release particles prepared by the method continuously release Fe²⁺OH is continuously generated, the efficiency of degrading organic matters by the OH is improved, and the dosage of a Fenton reagent is reduced;

3. the porous particles of the ferrous salt released by the Fenton reaction ferrous slow-release particles manufactured by the method are convenient to recover and can be used as good carriers of microorganisms.

4. The Fenton reaction ferrous iron slow-release particle secondary granulation process is simple, low in cost, free of large-scale equipment and suitable for large-scale production and application.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of Fenton reaction ferrous iron sustained-release particles and a manufacturing method thereof

FIG. 2 shows Fe in water of the ferrous iron controlled-release granules of the invention with different particle sizes²⁺Result of release of

Table 1 shows the parameters for manufacturing the ferrous iron controlled-release granules of the examples and comparative examples of the present invention

Table 2 shows the results of the mechanical properties of the ferrous iron sustained-release granules of the invention

Table 3 shows the evaluation results of the wastewater treatment effect of the ferrous iron sustained-release granules

Detailed Description

The present invention will be further described with reference to the following examples. The described embodiments and their results are only intended to illustrate the invention and should not be taken as limiting the invention described in detail in the claims.

Inorganic binder: portland cement, Jiangnan Cement plant

Organic binder: carboxymethyl cellulose, Huawei cellulose Ltd

Mineral material: xuyi Bo picture attapulgite (Xuyi Bo) Sphaet Co., Ltd, particle size 200 mesh

Ferrous sulfate heptahydrate: reagent

Water: tap water