阅读说明：本技术 一种具有控磷抑藻功能的改性陶粒及其制备方法和应用 (Modified ceramsite with phosphorus control and algae inhibition functions and preparation method and application thereof ) 是由 李乃稳 吴林骏 刘超 李龙国 谭博 贺宇欣 于 2019-09-10 设计创作，主要内容包括：本发明公开了一种具有控磷抑藻功能的改性陶粒及其制备方法,所述方法包括以下步骤：S1.预处理：对陶粒进行预处理,得到预处理陶粒；S2.改性：将所述预处理陶粒加入氯化铁溶液后对其进行搅拌,然后加入稀盐酸得到混合液,所述混合液在整个反应过程中呈酸性；S3.附着：所述混合液间歇进行静置和匀速搅拌,随后分离得到附着陶粒；S4.后处理：所述附着陶粒经过静置、烘干、灼烧、冷却、洗涤和再烘干的处理,即可得到所述改性陶粒；本发明还公开了所述改性陶粒在除藻方面的应用。本发明通过对比表面积大、具备较好吸附能力的陶粒进行化学改性,使得制得的所述改性陶粒具有很强的除藻能力,并且成本低廉,无二次污染,可多次重复使用。(The invention discloses a modified ceramsite with a phosphorus-controlling and algae-inhibiting function and a preparation method thereof, wherein the method comprises the following steps: s1, pretreatment: pretreating the ceramsite to obtain pretreated ceramsite; s2, modification: adding the pretreated ceramsite into a ferric chloride solution, stirring, and adding dilute hydrochloric acid to obtain a mixed solution, wherein the mixed solution is acidic in the whole reaction process; s3, attaching: the mixed solution is intermittently stood and stirred at a constant speed, and then is separated to obtain attached ceramsite; s4, post-processing: the attached ceramsite is subjected to standing, drying, firing, cooling, washing and re-drying treatment to obtain the modified ceramsite; the invention also discloses application of the modified ceramsite in removing algae. The invention carries out chemical modification on the ceramsite with large specific surface area and better adsorption capacity, so that the prepared modified ceramsite has strong algae removal capacity, low cost, no secondary pollution and repeated use.)

1. A modified ceramsite with the functions of controlling phosphorus and inhibiting algae is characterized in that: the modified ceramsite is obtained by mixing ceramsite with a ferric chloride solution, adjusting the pH value to acidity and then modifying.

2. The modified ceramsite with the functions of controlling phosphorus and inhibiting algae according to claim 1, is characterized in that: the particle size of the modified ceramsite is 2-4 mm.

3. The modified ceramsite with the functions of controlling phosphorus and inhibiting algae according to claim 1, is characterized in that: the particle size of the modified ceramsite is 3 mm.

4. The method for preparing the modified ceramsite as set forth in claims 1-3, wherein the method comprises the following steps: the method comprises the following steps:

s1, pretreatment: pretreating the ceramsite to obtain pretreated ceramsite;

s2, modification: adding the pretreated ceramsite into a ferric chloride solution, stirring, and adding dilute hydrochloric acid to obtain an acidic mixed solution;

s3, attaching: the mixed solution is intermittently stood and stirred at a constant speed, and is separated to obtain attached ceramsite;

s4, post-processing: and drying, firing, cooling, washing and drying the attached ceramsite to obtain the modified ceramsite.

5. The method of claim 4, wherein: in S1, the preprocessing method includes: washing the ceramsite with water; placing the washed ceramsite into dilute hydrochloric acid, and intermittently standing and uniformly stirring; then repeatedly soaking and washing the mixture by using water until the washing solution is neutral; and finally, drying the cleaned ceramsite to obtain the pretreated ceramsite.

6. The method of claim 4, wherein: in S2, the concentration of the ferric chloride solution is 0.5-2 mol/L.

7. The method of claim 4, wherein: in S2, the stirring speed is 120-200 r/min, and the stirring time is 10-20 min.

8. The method of claim 4, wherein: in S4, the burning temperature is 100-500 ℃.

9. The method of claim 4, wherein: in S4, the washing method includes: and repeatedly washing the fired and cooled ceramsite with water until the washing liquid is colorless, transparent and neutral.

10. The use of the modified ceramsite according to any one of claims 1-9 in algae removal.

Technical Field

The invention relates to the field of preparation of modified materials, in particular to modified ceramsite with functions of controlling phosphorus and inhibiting algae, and a preparation method and application thereof.

Background

When the fresh water body is in a eutrophic condition, water bloom is easily induced by proper conditions such as temperature, illumination, climate and hydrology. Under the influence of global warming and human activities, the eutrophication of water bodies of freshwater lakes, reservoirs and even rivers in various countries of the world is accelerated in recent years, and the water bloom phenomenon is continuously generated. Important lakes such as Taihu lake, nest lake and Dian lake in China all have water bloom many times, and the cell density of algae even reaches 10 when the water bloom is the most serious⁹And L, the normal function of the water body is lost, and the threat is brought to the drinking water safety of the coastal residents.

The existing algae removal methods comprise oxidation algae removal, flocculation algae removal, adsorption algae removal, ultrasonic algae removal, filtration algae removal and biological algae removal, and the defects of the methods are as follows:

1. oxidizing and removing algae: chemical oxidants such as chlorine dioxide, potassium permanganate and the like are added to remove algae through chemical oxidation, but secondary pollution is caused to a water body after a large amount of chemical oxidants are used;

2. flocculation algae removal: the purpose of removing turbidity and algae can be achieved by adding the coagulant with positive electricity to destabilize and flocculate the algae, but the adding amount is large, the cost is high, the application range is limited, and the method is not suitable for effectively inhibiting the algae for a long time;

3. filtering and removing algae: under the action of external force, the algae suspension passes through the filter medium, and algae with larger diameter is intercepted, so that the aim of removing algae is fulfilled, but a filter membrane and the medium for filtering are easy to block, the process is complex, and long-term maintenance is required;

4. biological algae removal: biological algae removal is an algae removal method for ecological balance control by utilizing a food chain, and comprises algae inhibition of aquatic animals, algae inhibition of aquatic plants and the like, but the method has long period and slow effect and needs long-term maintenance.

5. Adsorbing and removing algae: algae are adsorbed on the surface of the adsorption material by utilizing the large specific surface area and developed porosity of the adsorption material such as ceramsite, but the adsorption effect is poor, and no method is adopted for continuously removing algae after the adsorption is saturated;

in summary, there is a need for an algae removal method that has high algae removal capability, low cost, no secondary pollution and can be reused many times.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides modified ceramsite with the functions of controlling phosphorus and inhibiting algae as well as a preparation method and application thereof, so as to achieve the effects of efficiently removing algae, low cost, no secondary pollution and repeated use.

The purpose of the invention is realized by the following technical scheme: the modified ceramsite with the functions of controlling phosphorus and inhibiting algae is obtained by mixing ceramsite with a ferric chloride solution, adjusting the pH value to be acidic and then modifying.

The ceramsite is an artificial light aggregate which is prepared by directly crushing or processing natural minerals or industrial wastes and the like serving as main raw materials into granules and then sintering and expanding the granules, is a porous ceramic granular substance with a closed microporous structure, has large specific surface area, good chemical and thermal stability, good adsorption performance, easy regeneration and convenient reutilization.

According to the analysis of the chemical components of the algae, the ratio of nitrogen and phosphorus taken by the algae from the outside is about 16:1, namely, when the algae grows, every 1 unit of phosphorus is absorbed from the outside, and 16 units of nitrogen are absorbed at the same time, so that the phosphorus is a main limiting factor of water eutrophication.

By adopting the technical scheme, when the modified ceramsite is used for removing algae, a large amount of Ca can be dissolved out of the ceramsite during soaking²⁺Thereby generating calcium phosphate sediment with phosphate in the water body, wrapping algae cells in the process of generating the calcium phosphate, and finally precipitating together, thereby achieving the effect of efficiently removing algae; meanwhile, as the isoelectric point of the algae is very low, the surface of the algae in the water body is negatively charged, and Fe is introduced³⁺The modification of the ceramsite can increase the isoelectric point of the surface of the ceramsite, and the ceramsite plays a role in electrically neutralizing algae in a water body, so that the algae are destabilized to achieve the effect of flocculation and sedimentation.

Preferably, the particle size of the modified ceramsite is 2-4 mm.

Preferably, the particle size of the modified ceramsite is 3 mm.

The ceramsite has overlarge particle size, is heated unevenly during firing possibly in the modification process, and is not soaked thoroughly during mixing, so that the phosphorus removal effect of the ceramsite is reduced to a certain degree; the particle size is too small, the ceramsite is suspended in water, and although the ceramsite has strong removal capacity, the ceramsite also influences the turbidity of a water body.

Through the technical scheme, the particle size of the modified ceramsite is limited to 3mm, so that the effect of fully modifying the modified ceramsite without influencing the turbidity of a water body is achieved.

A preparation method of modified ceramsite with phosphorus control and algae inhibition functions comprises the following steps:

s1, pretreatment: pretreating the ceramsite to obtain pretreated ceramsite;

s2, modification: adding the pretreated ceramsite into a ferric chloride solution, stirring, and adding dilute hydrochloric acid to obtain an acidic mixed solution; the beneficial effects of adding dilute hydrochloric acid to obtain an acidic mixed solution are as follows: (1) alkaline substances can be continuously dissolved out of the pretreated ceramsite in the aqueous solution, the pH value of the aqueous solution can be kept at 7.5-8 by the acidic mixed solution, the influence of the pH value on ceramsite algae removal is reduced, and secondary pollution caused by algae removal is avoided; (2) the ferric chloride solution is prevented from being hydrolyzed in water to generate ferric hydroxide precipitate, so that the effect of preventing the precipitate from wrapping ceramsite to block gaps is achieved; (3) the acidic mixed solution can change the water-insoluble calcium salt in the ceramsite into the water-soluble calcium salt.

S3, attaching: the mixed solution is intermittently kept stand and stirred at a constant speed to ensure that the ceramsite is fully contacted and attached with the ferric chloride solution, and then the ceramsite is separated to obtain attached ceramsite; wherein, after standing the mixed solution for 6 hours each time, stirring the mixed solution at a constant speed of 90r/min for 2 min.

S4, post-processing: and drying, firing, cooling, washing and drying the attached ceramsite to obtain the modified ceramsite.

Preferably, in S1, the preprocessing method includes: washing the ceramsite with water; placing the washed ceramsite into hydrochloric acid, and intermittently standing and uniformly stirring; then repeatedly soaking and washing the mixture by using water until the washing solution is neutral; and finally, drying the cleaned ceramsite to obtain the pretreated ceramsite.

Preferably, in S2, the concentration of the ferric chloride is 0.5-2 mol/L, and preferably 1 mol/L.

According to the technical scheme, when the concentration of the ferric chloride solution is 0.5-1 mol/L, the removal rate of the modified ceramsite to the algae is gradually increased; when the concentration of the ferric chloride solution is 1mol/L, the removal rate reaches the balance; when the concentration of ferric chloride is 1-2mol/L, the removal rate is almost unchanged; therefore, 1mol/L is the optimal concentration of the ferric chloride solution, and the modified ceramsite prepared by the method has the best removal effect on algae.

Preferably, in S2, the stirring speed is 120-200 r/min, and the stirring time is 10-20 min.

By the technical scheme, the stirring speed and time are limited, and the effect of ensuring the full contact of the pretreated ceramsite and the ferric chloride solution is achieved.

Preferably, in S2, the concentration of the dilute hydrochloric acid is 1mol/L, and the volume ratio of the dilute hydrochloric acid to the mixed solution is 1: 10.

When the concentration of the dilute hydrochloric acid is 0, 0.5mol/L and 2mol/L, the removal rate of chlorophyll a is increased and then slightly reduced; when the concentration of the dilute hydrochloric acid is 1mol/L and 1.5mol/L, the removal rate of the chlorophyll a is increased and then stabilized, and the removal rates of 1mol/L and 1.5mol/L are equivalent; therefore, when the concentration of the dilute hydrochloric acid is 1mol/L, the effect is best and the economy is best, and finally, the removal rate of the chlorophyll a reaches 94.03 percent and is improved by 18 percent compared with the removal rate of ceramsite without hydrochloric acid.

Preferably, in S4, the burning temperature is 100-500 ℃, preferably 500 ℃.

By adopting the technical scheme, when the ignition temperature is 100-500 ℃, the removal rate of the ceramsite is gradually increased; when the burning temperature is 500 ℃, the removal rate of the modified ceramsite is highest; when the temperature is 700 ℃ or 900 ℃, the modified ceramsite has no removal rate, and the algae is increased continuously.

Preferably, in S4, the washing method is: and repeatedly washing the fired and cooled ceramsite with water until the washing liquid is colorless, transparent and neutral.

An application of modified ceramsite with functions of controlling phosphorus and inhibiting algae in algae removal.

The invention has the beneficial effects that:

1. the invention relates to a modified ceramsite with phosphorus control and algae inhibition functions and a preparation method thereof, which introduces Fe³⁺The ceramsite is modified in a mode of increasing the isoelectric point of the surface of the ceramsite, and dissolved substances also increase the potential in the water body, so that the electric neutralization effect is exerted on the algae in the water body, the algae are destabilized, and the flocculation and sedimentation effect of the algae is achieved.

2. The invention relates to a modified ceramsite with the functions of controlling phosphorus and inhibiting algae and a preparation method thereof²⁺Thereby generating calcium phosphate sediment with phosphate in the water body, wrapping algae cells in the process of generating the calcium phosphate, finally precipitating together, and achieving the effect of efficiently removing algae.

3. According to the modified ceramsite with the functions of controlling phosphorus and inhibiting algae and the preparation method thereof, the ceramsite is chemically modified, so that the modified ceramsite has strong algae removal capacity and can be repeatedly used for many times, and the effects of efficient algae removal, no secondary pollution and low cost are achieved.

Drawings

FIG. 1 is a graph showing the removal rate of the modified ceramsite in example 1 with respect to time;

FIG. 2 is a graph showing the removal rate of the modified ceramsite of example 1 repeatedly used as a function of time;

FIG. 3 is a graph showing the removal rate of the modified ceramsite in example 2 with respect to time;

FIG. 4 is a graph showing the removal rate of the modified ceramsite in example 2 with respect to time.

Detailed Description

The technical solutions of the present invention are further described in detail below with reference to the accompanying drawings, but the scope of the present invention is not limited to the following.