CN115845795B - Water body purifying material, preparation method thereof and method for purifying water body - Google Patents

Abstract

The present invention relates to a water purification material and a preparation method thereof and a method for purifying water. The water purification material is in powder form, and its preparation raw materials include, by mass, lanthanum modified zeolite, clay, rock-forming minerals, clinoptilolite, silica sol, volcanic ash, and soluble carbonate. The material has abundant pores in its composition, and can absorb organic matter and heavy metal ions after being sprinkled into the water body, and can easily settle to the bottom of the water body to form a covering film, and at the same time, the covering film is conducive to the growth of aquatic plants.

Description

A water purification material and a preparation method thereof and a method for purifying water

Technical Field

The invention belongs to the technical field of water treatment, and in particular relates to a water purification material and a preparation method thereof, and a method for purifying water.

Background Art

With the rapid economic development, the living standards of residents are constantly improving, urban construction is constantly expanding, and urban water pollution is becoming increasingly serious. Rivers, lakes, reservoirs and ponds in cities and rural areas are seriously polluted. The pollutant content they receive far exceeds their own water environment capacity, showing unpleasant colors (black or blackish), and (or) emitting unpleasant odors (smelly or foul). The main substances that make black and smelly water appear black are divided into two parts: ① insoluble substances that exist in the water in the form of solid or adsorbed on suspended particles; ② colored organic compounds soluble in water (mainly humus organic matter). Specifically: ① When the content of organic pollutants in the water body is too high, under the action of microorganisms, the decomposition of organic matter will consume a large amount of dissolved oxygen, causing the water body to become anoxic or anaerobic state; under anoxic and anaerobic conditions, metal ions such as iron and manganese in the water body form sulfides with sulfur ions in the water, and the sulfides are adsorbed on the suspended particles to make the water body appear black; ② Under the influence of hydraulic scouring, human disturbance and biological activities, the black sediment particles will cause the deposited black sediment to re-suspend, causing a large number of suspended particles to float in the water, and then under a series of physical, chemical and biological comprehensive effects, the pollutants adsorbed on the sediment particles are exchanged with the pore water, thereby releasing pollutants into the water body, causing the water body to turn black and smelly.

The fine particles in black and smelly water bodies, especially colloidal particles, are difficult to precipitate naturally and are the main reason why the water is turbid and black in appearance. These fine particles are mainly insoluble suspended particles with low biodegradability, and are not easily degraded by microorganisms, and may even inhibit the growth of microorganisms. Therefore, in the treatment of black and smelly water bodies, the main measure to solve the problem of black water bodies is to remove suspended particles in the water body.

There are many types of technologies and patents related to the purification of polluted water, including physical methods based on screening and interception, gravity separation, matrix filtration, porous material adsorption, etc.; chemical methods based on ion exchange, chemical precipitation, breakpoint chlorination, electrodialysis, electrochemical treatment, catalytic cracking, neutralization, oxidation, etc.; and biological methods such as activated sludge method and biofilm method. However, due to the limitations of process conditions, these methods are mainly used in sewage treatment plants.

For black and smelly water bodies such as rivers, lakes, reservoirs and ponds in cities and rural areas, the commonly used treatment methods are mainly physical and biological methods such as artificial wetlands, ecological ponds, land infiltration, and microbial purification, mainly to maximize the self-purification of water bodies; however, this type of process often requires large construction costs, land costs and later operating costs, and the purification cycle is relatively long. In order to quickly solve the turbidity, blackening and stinking problems of black and smelly water bodies, it is currently mainly treated in situ through external integrated equipment, and coagulants need to be added for coagulation and sedimentation to remove suspended particles and pollutants that cause the water body to turn black. The basic principles of coagulation and sedimentation are compression of the double electrical layer; electrical neutralization and adsorption bridging.

At present, the coagulants that can be used for integrated equipment to purify water or directly added to black and smelly water for in-situ purification and removal of suspended particles in water are mainly chemical components. Taking into account factors such as biological safety, in order to avoid adverse effects and secondary pollution caused by residual chemical agents on the water environment and water ecology, the addition should be carried out with caution. In order to achieve rapid purification of water, remove suspended particles and pollutants in the water to improve water transparency, and promote microorganisms and plants in the water to purify water, some universities and research institutes have developed environmentally friendly water purification materials that can be used in integrated equipment and directly sprayed in black and smelly waters through research on hydrated aluminum silicate minerals with layered structures.

A Chinese patent application with publication number CN1817438A discloses a method for preparing a wastewater phosphorus removal adsorbent using ion-absorption rare earths, comprising preparing an ion-absorption rare earth ore and clay in a weight ratio of 10:0.5-4, granulating, and roasting at a temperature of 500-800°C for 1-3 hours, entering a reactor and first circulating activation with an acid activation solution for 4-8 hours, then adjusting the pH value of the activation solution to 8-12 with an alkali solution, and then circulating activation treatment for 4-8 hours, and then drying at a temperature of 100-120°C for half an hour, and then heating at a heating rate of 10-20°C per minute, finally roasting at a temperature of 400-700°C for 0.5-2 hours, and cooling to obtain an ion-absorption rare earth adsorbent. The inventive method uses ion-adsorbing rare earth ore as raw material, which can effectively adsorb suspended particles in water to form large flocculent precipitates that precipitate quickly. However, the preparation cost of this type of ion adsorbent is high, the process for preparing the adsorbent is complex, and the production efficiency is low. It can be used for laboratory test preparation and use, but is not suitable for large-scale batch production and cannot be applied and promoted in the market and engineering applications.

Therefore, one object of the present application is to provide a method for preparing a water quality improvement composition containing environmentally friendly active natural minerals, which composition can be manufactured at low cost, has a stable production process, can be mass-produced, and is applied to black and odorous water treatment projects.

Another object of the present application is to provide a water quality improvement composition containing environmentally friendly active natural minerals, and can improve the water purification (coagulation and sedimentation) efficiency of integrated treatment equipment, or can coagulate and precipitate various suspended particulate pollutants without passing through equipment, and improve water quality through a combined process of microorganisms and aquatic plants.

Summary of the invention

In order to achieve the above-mentioned purpose, according to one aspect of the present application, a water purification material is provided, which has abundant pores in its composition, can adsorb organic matter and heavy metal ions after being sprinkled into the water body, and easily settles to the bottom of the water body to form a covering film. Moreover, during the sedimentation process of the material, the soluble carbonate in its powder structure gradually dissolves, so that while sinking, more pores are released, increasing the adsorption amount, especially increasing the adsorption amount of underwater pollutants. In addition, the carbonate also plays a role in regulating the pH value of the water body during the dissolution process.

Specifically, the water material is in powder form, and its preparation raw materials include, by mass:

10-30 parts of lanthanum modified zeolite

20-40 parts clay

12-20 parts rock-forming minerals

8-10 parts clinoptilolite

20-30 parts silica sol

4-8 parts volcanic ash, and

2-10 parts of soluble carbonate.

Preferably, the rock-forming mineral is selected from one or two of muscovite and feldspar. Muscovite and feldspar have a large specific gravity and are harmless to aquatic ecosystems, increase the specific gravity of aggregates, facilitate rapid sedimentation in water, and prevent the sediment from floating again during sedimentation. Muscovite and feldspar can be used alone or in combination of at least two. It is preferred to use a combination of muscovite and feldspar, preferably with a weight ratio of 3-7:1-5, to effectively control the formation and precipitation rate of agglomerates.

The clay mineral is a clay mineral with high cation exchange capacity, preferably one or more of vermiculite, montmorillonite and illite.

The lanthanum-modified zeolite is obtained by grinding natural zeolite into powder, mixing it with LaCl ₃ solution, filtering it with deionized water, drying it, and calcining it to obtain a white powder. It has the effect of removing phosphorus and can inhibit the growth of algae.

The chemical formula of the clinoptilolite is Na(AlSi ₅ O ₁₂ )·4H ₂ O, and it is in the form of white or colorless flake or plate crystals.

The volcanic ash is selected to be neutral, porous, aluminum- and silicon-containing volcanic ash. It is found in the experiment that adding a certain amount of volcanic ash is conducive to grinding into porous particles. If volcanic ash is not added, the premix after sintering needs higher strength when ground into powder, and the ground powder particles are uneven in size, and many pores have been filled with fine powder. The product after sintering with volcanic ash is easier to grind into fine powder, and the pore structure of the powder is more complete.

The soluble carbonate is selected from one or more of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate.

More preferably, the rock-forming mineral is selected from albite, and the clay is selected from illite. Experiments have found that, under the condition that other conditions remain unchanged, the water adsorption capacity obtained by selecting this combination is larger, and it has a better promoting effect on the growth of aquatic plants.

The preparation method of the water purification material comprises the following steps:

1) crushing lanthanum-modified zeolite, clay, rock-forming minerals, and clinoptilolite into powders with a particle size of less than 5 mm, preferably crushing each component into powders with a particle size of 260 mesh or less, and then stirring and mixing with silica sol and volcanic ash, and further ball milling to obtain premix I;

2) drying the premix I obtained in step 1) (preferably at a temperature of 150-180° C.), grinding it into powder, and then mixing it evenly with a soluble carbonate to obtain a premix II; preferably, ball milling is used for mixing.

3) The premix II obtained in step 2) is calcined at high temperature, rapidly cooled, and ground into powder again to obtain the water purification material.

Preferably, the calcination temperature in step 3) is 850-1000° C., preferably 850-900° C. Also preferably, the rapid cooling is to reduce the temperature to below -20° C. within 30 minutes.

Preferably, the soluble carbonate is sodium carbonate, and the calcination temperature in step 3) is 850-1000°C.

Preferably, in step 3), the ball milling is performed to a size of 200-300 mesh.

The present invention further provides a method for purifying water, the method comprising the step of spreading the aforementioned water purification material on the surface of the water body to be purified. Preferably, the method comprises: 1) spreading the aforementioned water purification material on the surface of the water body to be purified; 2) disturbing the water body so that the water purification material sprayed on the water area to be treated can be gathered and the floating suspended particle pollutants can be precipitated; 3) throwing submerged plants to purify pollutants through plant leaves and roots to inhibit the growth of algae.

Preferably, the method comprises: 1) spreading the aforementioned water purification material onto the surface of the water body to be purified; 2) disturbing the water body so that the water purification material sprayed on the water body to be treated can be aggregated and the floating suspended particulate pollutants can be precipitated; 3) adding solidified carrier microorganisms into the water body; 4) throwing submerged plants to purify pollutants through plant leaves and roots, thereby inhibiting the growth of algae.

The solidified carrier microorganism is selected from one or more of photosynthetic bacteria, nitrifying bacteria, multi-enzyme bacteria and denitrifying bacteria, and its usage is 1-1.5 times the mass of the water purification material.

Preferably, the water body is disturbed by a hull such as a speedboat.

Preferably, the submerged plants are selected from foxtail algae, hornwort, water chestnut, hydrilla verticillata, and Vallisneria.

Preferably, the dosage of the water purification material is 20-80 g/m2 of water, preferably 40-60 g/m2 of water.

The lanthanum modified zeolite is obtained by grinding natural ore into powder, adding 0.05 mol/L LaCl ₃ solution, the solid-liquid ratio of natural zeolite to LaCl ₃ solution is 1:20-25, the solution pH is adjusted to 9-10, stirring is continued for 5-10 hours, washing with deionized water and then filtering, and the obtained powdery solid is dried and calcined at 400°C to 800°C.

As described above, the mixed material for purifying water of the present application can remove suspended particles and pollutants that cause the water to turn black, inhibit algae growth, improve water transparency, and purify the water, providing the necessary preliminary conditions for building a complete water ecosystem. In addition, the mixed material for purifying water of the present application can purify the water inlet source without additional treatment facilities, reduce the treatment load of various water treatment facilities, and reduce the construction cost of related facilities and the cost of chemicals for later operation and maintenance.

Technical Effects of the Invention

1. The water purification material has a strong adsorption capacity for heavy metals and organic matter. Even when it is just put into use and has not been maintained, it can significantly reduce the heavy metals, total phosphorus, total nitrogen, and ammonia nitrogen in black and smelly water bodies and improve transparency;

2. After adding submerged plants for maintenance, the content of heavy metals, total phosphorus, total nitrogen, ammonia nitrogen, and COD value are further reduced, the transparency is significantly improved, and the thickness of the bottom mud is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a comparison of the Jialu River before (right half) and one year after (left half) the treatment.

DETAILED DESCRIPTION

Note 1: In all the following examples, unless otherwise specified, the amounts of raw materials are in parts by mass.

Note 2: Condition of the Jialu River section before treatment

The main water quality indicators in the Jialu River section are: transparency 15-30cm, COD data 24.57mg/L, SS content 46.35mg/L, total phosphorus content 0.41mg/L, total nitrogen content 10.06mg/L, ammonia nitrogen content 1.72mg/L;

The bottom mud in the Jialu River section is about 75cm thick, with an organic matter content of about 4.13%, heavy metals: Cu about 40.3mg/kg, Pd about 45.5mg/kg; the structure of the bottom mud is: pore volume 0.21-0.43ml/g, specific surface area ^200-300m2 /g, pore diameter 5-8nm.

Preparation Example 1: Preparation of lanthanum-modified zeolite

The natural zeolite was ground into powder with a size of less than 100 mesh, and added into a 0.05 mol/L LaCl ₃ solution, wherein the solid-liquid ratio of the natural zeolite to the LaCl ₃ solution was 1:25, and the pH value of the solution was adjusted to 10. The mixture was stirred for 10 hours, and then filtered after washing with deionized water. The obtained powdery solid was dried and calcined at 600° C. to obtain the lanthanum-modified zeolite.

Preparation Example 2 Preparation of water purification material

1) 25 parts of the lanthanum-modified zeolite obtained in Preparation Example 1, 30 parts of illite, 15 parts of albite, and 8 parts of clinoptilolite were crushed into particles with a diameter of less than 200 mesh, and then stirred and mixed with 25 parts of silica sol and 6 parts of volcanic ash, and then further ball-milled to obtain a premix I;

2) drying the premix I obtained in step 1) at 180° C. for 2 hours, grinding it into powder, and then mixing it evenly with 5 parts of sodium carbonate to obtain premix II;

3) The premix II obtained in step 2) is calcined at 850°C, rapidly cooled to -20°C, and ground again into a powder of 200-300 mesh.

Preparation Example 3 Preparation of water purification material

1) 15 parts of the lanthanum-modified zeolite obtained in Preparation Example 1, 25 parts of illite, 20 parts of albite, and 10 parts of clinoptilolite were crushed into particles with a diameter of less than 200 mesh, and then stirred and mixed with 20 parts of silica sol and 6 parts of volcanic ash, and then further ball-milled to obtain a premix I;

2) drying the premix I obtained in step 1) at 180° C. for 2 hours, grinding it into powder, and then mixing it evenly with 5 parts of sodium carbonate to obtain premix II;

3) The premix II obtained in step 2) is calcined at 850°C, rapidly cooled to -20°C, and ground again into a powder of 200-300 mesh.

Preparation Example 4 Preparation of water purification material

1) 15 parts of the lanthanum-modified zeolite obtained in Preparation Example 1, 40 parts of illite, 12 parts of albite, and 8 parts of clinoptilolite were crushed into particles with a diameter of less than 200 mesh, and then stirred and mixed with 20 parts of silica sol and 4 parts of volcanic ash, and then further ball-milled to obtain a premix I;

2) drying the premix I obtained in step 1) at 180° C. for 2 hours, grinding it into powder, and then mixing it evenly with 5 parts of sodium carbonate to obtain premix II;

3) The premix II obtained in step 2) is calcined at 850°C, rapidly cooled to -20°C, and ground again into a powder of 200-300 mesh.

Preparation Example 5 Preparation of water purification material

The other conditions are the same as those in Preparation Example 2, except that the calcination is carried out at a high temperature of 900° C. in step 3).

Preparation Example 6 Preparation of water purification material

The other conditions are the same as those in Example 1, except that the calcination is carried out at a high temperature of 1000° C. in step 3).

Preparation Example 7 Preparation of water purification material

The other conditions are the same as those in Preparation Example 2, except that the calcination is performed at a high temperature of 1200° C. in step 3).

Comparative Preparation Example 1 Preparation of water purification material

1) 25 parts of the lanthanum-modified zeolite obtained in Preparation Example 1, 30 parts of illite, 15 parts of albite, and 8 parts of clinoptilolite were crushed into particles with a diameter of less than 200 mesh, and then stirred and mixed with 25 parts of silica sol, and then further ball-milled to obtain a premix I;

2) drying the premix I obtained in step 1) at 180° C. for 2 hours, grinding it into powder, and then mixing it evenly with 5 parts of sodium carbonate to obtain premix II;

3) The premix II obtained in step 2) is calcined at 850°C, rapidly cooled to -20°C, and ground again into a powder of 200-300 mesh.

Comparative Preparation Example 2 Preparation of Water Purification Material

1) 25 parts of the lanthanum-modified zeolite obtained in Preparation Example 1, 30 parts of illite, 15 parts of albite, and 8 parts of clinoptilolite were crushed into particles with a diameter of less than 200 mesh, and then stirred and mixed with 25 parts of silica sol and 6 parts of volcanic ash, and then further ball-milled to obtain a premix I;

2) drying the premix I obtained in step 1) at 180° C. for 2 hours and grinding it into powder;

3) The powder obtained in step 2) is calcined at 850°C, rapidly cooled to -20°C, and ground again into a powder of 200-300 mesh.

Examples 1-6 and Comparative Examples 1-2 (using the water purification materials of Preparation Examples 2-7 and Comparative Preparation Examples 1-2, respectively)

The water quality management of the Jialu River section includes the following steps:

Step 1: Take samples of water in the Jialu River section for testing. After one month of water quality monitoring, obtain the content of water characteristic indicators in the Jialu River section; among them, the transparency is 20-25cm, the monthly average water quality data of COD is 24.57mg/L, and the SS content is 46.35mg/L. Based on the Class IV water characteristic indicators of the Surface Water Environmental Quality Standard, the total phosphorus content is 0.41mg/L, which is 4 times higher than the standard, the total nitrogen content is 10.06mg/L, which is 7 times higher than the standard, and the ammonia nitrogen content is 1.72mg/L, which is 1.2 times higher than the standard.

Step 2, sampling and testing the bottom mud in the Jialu River section, the bottom mud contains about 4.13% organic matter, heavy metals include: Cu about 40.3mg/kg, Pd about 45.5mg/kg; the structure of the bottom mud is: pore volume 0.21-0.43ml/g, specific surface area ^200-300m2 /g, pore diameter 5-8nm.

Step 3: intercept pollution in the pollution control area to prevent the entry of external pollution sources during the control process, and isolate the polluted area to be repaired and divide it into 8 areas.

Step 4: The Jialu River bank does not have the conditions for using integrated water purification equipment, so the Jialu River treatment method is to directly and evenly sprinkle the water purification materials prepared in Preparation Examples 2-7 and Comparative Preparation Examples 1-2 at 400g/ ^m2 (400g of water purification material is added per square meter of water) in the Jialu River waters (corresponding to the 8 areas separated in Step 3 respectively), and use a speedboat to disturb the water body back and forth to aggregate the water purification materials sprayed on the water area to be treated, precipitate the floating suspended particulate pollutants, and the precipitated aggregates form a covering layer on the surface of the bottom mud.

Step 5, adding solid carrier microorganisms (dosage of about 400 g/m ² ) into the water body, the solid carrier microorganisms settle to the surface of the sludge to form a covering layer, and further decompose the pollutants in the black and smelly sludge. The solid carrier microorganisms are photosynthetic bacteria.

Step 6: Plant aquatic plants in the Jialu River section, and use water purification materials and solidified carrier microorganisms to purify the water and reduce sediment pollutants. The specific planting method is: in the still water area with a water depth of 1m to 1.5m, plant Vallisneria, Hydrilla verticillata, and Foxtail Algae in a throwing method, with the density controlled at 25 clumps/ ^m2 .

Step 7: Conduct one-year water quality testing and operational maintenance on the Jialu River section that has completed treatment.

Table 1 Water quality and sediment test data obtained immediately after step 4 in Examples 1-6 and Comparative Examples 1-2

Table 2 Water quality and sediment test data of Examples 1-6 and Comparative Examples 1-2 after one year of treatment

It can be seen from Table 1 above that the water purification material in this application has a certain adsorption effect on heavy metal ions and organic pollutants in black and smelly water bodies after stirring and settling. Although the method of planting aquatic plants is adopted, the general black and smelly water bodies can basically meet the standards after one year.

Examples 7-12 and Comparative Examples 3-4 (using the water purification materials of Preparation Examples 2-7 and Comparative Preparation Examples 1-2, respectively)

The simulated wastewater containing the following heavy metal ions and organic pollutants was prepared, and the water purification materials of Preparation Examples 2-7 and Comparative Preparation Examples 1-2 were sprinkled into the simulated wastewater at an amount of 400 g per ton of simulated wastewater, respectively, and stirred for half an hour. The test results are as follows:

Table 3 Adsorption performance test data of Examples 7-12 and Comparative Examples 3-4

As can be seen from Table 3 above, the water purification material in the present application has a good adsorption effect on heavy metal ions and acidic organic matter such as phenol.

Claims (9)

1. The water purification material is powdery and is characterized by comprising the following preparation raw materials in parts by mass:

10-30 parts of lanthanum modified zeolite

20-40 Parts of clay

12-20 Parts of rock forming mineral

8-10 Parts of clinoptilolite

20-30 Parts of silica sol

4-8 Parts of volcanic ash, and

2-10 Parts of sodium carbonate;

The preparation of the water body purifying material comprises the following steps:

1) Crushing lanthanum modified zeolite, clay, rock forming mineral and clinoptilolite into powder with the particle size of less than 5mm, stirring and mixing the powder with silica sol and volcanic ash, and then further ball-milling and mixing the powder to obtain a premix I;

2) Drying the premix I obtained in the step 1), grinding the dried premix I into powder, and uniformly mixing the powder with soluble carbonate to obtain a premix II;

3) Calcining the premix II obtained in the step 2) at a high temperature, quenching, grinding into powder again, and obtaining the water body purifying material, wherein the calcining temperature is 850-1000 ℃.

2. The water purification material of claim 1, wherein the rock-forming mineral is selected from one or both of muscovite and feldspar.

3. The water purification material of claim 1, wherein the clay is selected from one or more of vermiculite, montmorillonite, and illite.

4. The water purification material of claim 1, wherein the lanthanum-modified zeolite is prepared by grinding natural zeolite into powder, mixing LaCl ₃ solution, filtering with deionized water, drying, and calcining.

5. The method of preparing a water purification material of claim 1, wherein the rock-forming mineral is selected from albite and the clay is selected from illite.

6. The process according to claim 5, wherein the calcination temperature in step 3) is 850 to 900 ℃.

7. A method of purifying a body of water, the method comprising the step of scattering the water purification material of any one of claims 1 to 4 or the water purification material obtained by the method of any one of claims 5 to 6 onto the surface of a body of water to be purified.

8. A method of purifying a body of water as claimed in claim 7, wherein the method comprises: 1) The water purifying material is scattered on the surface of the water to be purified; 2) Disturbing the water body to gather the water body purifying material sprayed on the water area to be treated and precipitate floating suspended particle pollutants; 3) Throwing submerged plants to purify pollutants through plant leaves and root systems, so as to inhibit the growth of algae.

9. A method of purifying a body of water as claimed in claim 7, wherein the method comprises: 1) The water purifying material is scattered on the surface of the water to be purified; 2) Disturbing the water body to gather the water body purifying material sprayed on the water area to be treated and precipitate floating suspended particle pollutants; 3) Adding immobilized carrier microorganisms into the water body; 4) Throwing submerged plants to purify pollutants through plant leaves and root systems, so as to inhibit the growth of algae.