Stabilizer for heavy metals and phosphorus in eutrophic water body as well as preparation method and application of stabilizer

Abstract

The invention discloses a stabilizer for heavy metals and phosphorus in a eutrophic water body as well as a preparation method and application of the stabilizer, the stabilizer comprises the following effective components: bentonite, medical stone, molybdic acid and biochar, the mass ratio of the bentonite to the medical stone is (1-3): (3-1), the content of the molybdic acid is 2.5-40g / kg, and the content of the biochar is 20-80g / kg. The core of the invention lies in a synergistic effect mechanism among the biochar, the nonmetallic mineral material and the molybdic acid, and the three components cooperate with each other, so that effective precipitation of heavy metals and phosphorus is promoted, and thorough removal of phosphorus and heavy metals from a water body is realized through subsequent desilting operation. According to the innovative scheme, the treatment efficiency is remarkably improved, deep purification of eutrophication water body pollutants is achieved under the synergistic effect, an efficient and stable solution is provided for water body remediation and environmental protection, and extremely high application value and environmental benefits are shown.

Description

Technical Field

[0001] The invention belongs to the field of water purification, and specifically relates to a stabilizer for heavy metals and phosphorus in eutrophic water bodies, and a preparation method and application thereof. Background Art

[0002] Under the current severe background of industrial production, heavy metal elements continue to invade water bodies along with wastewater discharge, especially in artificial rivers and lakes, causing significant pollution problems due to long-term accumulation. This problem, coupled with the excessive accumulation of nutrients such as nitrogen and phosphorus in water bodies, leads to eutrophication of water bodies. Among them, phosphorus is the key factor triggering eutrophication, making this complex pollution - the coexistence of heavy metal pollution and eutrophication - an environmental problem that needs to be overcome urgently.

[0003] For the removal of phosphorus in water, the existing technologies mainly cover three categories: biological, chemical and physical methods. Although biological methods are green and environmentally friendly, they are limited by the characteristics of long cycles and slow effects; physical methods mostly stay on surface treatment, it is difficult to get to the root of pollution, and it is not capable of deep removal of heavy metals and phosphorus. As for chemical methods, such as precipitation and stable adsorption, although they can achieve the removal of heavy metals or phosphorus alone or in combination, there is a risk that the fixed pollutants will be released again over time, which may trigger a new pollution cycle.

[0004] Most of the water remediation materials currently on the market only target the surface of water bodies or rely on sedimentation mechanisms to remove pollutants, and their ability to purify the suspended layer of water bodies is limited. In addition, the adsorption rate and stability of the material are directly related to the effectiveness of the remediation and are key indicators for evaluating material performance. Therefore, it is particularly urgent to develop a new material that can act on all levels of water bodies in an all-round way and can efficiently and stably adsorb heavy metals and phosphorus.

[0005] Non-metallic mineral materials and molybdic acid have begun to show their potential in the field of water body remediation, showing broad application prospects. However, their practical application still faces multiple technical challenges. Specifically, the selection and modification of non-metallic mineral materials require fine-tuning, and the improvement of their adsorption capacity and efficiency is the core consideration. At the same time, the regeneration and recycling mechanism of the materials also needs to be further improved. For molybdic acid, it is crucial to ensure its stability and safety during use. Exploring the best conditions of use to optimize catalytic performance and in-depth exploration of its catalytic mechanism are key steps in promoting its application. Overcoming these technical difficulties will not only broaden the scope of application of non-metallic mineral materials and molybdic acid in water body remediation, but will also inject new vitality into the cause of environmental protection and pollution control, and promote the development of this field to a higher level. Summary of the invention

[0006] Technical problem to be solved: The present invention is dedicated to solving the problem of stabilization treatment of heavy metal and phosphorus pollution in eutrophic water bodies, and particularly proposes a stabilizer for heavy metals and phosphorus in eutrophic water bodies, and its preparation method and application. The present invention aims to overcome the problems of low treatment efficiency, insufficient stability and potential secondary pollution risks commonly found in traditional treatment methods.

[0007] Specifically, the present invention cleverly combines the synergistic effect of non-metallic mineral materials and molybdic acid to design a stabilizer that can efficiently and stably remove heavy metals and phosphorus from water. This stabilizer not only has the ability to simultaneously treat heavy metal and phosphorus compound pollution, but also exhibits excellent adsorption rate and long-lasting adsorption efficiency in the treatment process, effectively avoiding the re-release of pollutants after treatment, thereby ensuring the safety and cleanliness of the environment.

[0008] By implementing the present invention, the efficiency and stability of water body restoration work will be significantly improved, bringing an innovative solution to the field of environmental protection and pollution control. The present invention not only improves the removal efficiency of pollutants, but also makes breakthroughs in stability and long-term effects, providing a solid guarantee for the long-term health and ecological balance of water bodies.

[0009] Technical solution: A stabilizer for heavy metals and phosphorus in eutrophic water bodies, wherein the active ingredients include bentonite, medical stone, molybdic acid and biochar, wherein the mass ratio of the bentonite to the medical stone is (1-3):(3-1), the molybdic acid content is 2.5-40 g / kg, and the biochar content is 20-80 g / kg.

[0010] The bentonite is alkalized and modified. The alkalization modification steps are as follows: grind the bentonite and pass it through a 20-mesh sieve, mix the sieved bentonite with a 0.20 mol / L potassium bicarbonate solution at a solid-liquid ratio of 1 g:10 mL, adjust the pH value to 8.00 with potassium hydroxide or hydrochloric acid, stir at room temperature, centrifuge, filter, dry the obtained bentonite at 60-80°C, and grind until it passes through a 200-mesh sieve.

[0011] The above medical stone is acidified and modified. The acidification modification steps are: crushing and grinding the medical stone and passing it through a 20-mesh sieve, mixing the medical stone with a hydrochloric acid solution with a mass fraction of 10% at a solid-liquid ratio of 1g:10mL, stirring at 80°C, centrifuging and washing with deionized water until there is no chloride ion, removing the supernatant after centrifugation, drying the obtained medical stone at 60-80°C, and grinding until all of it passes through a 200-mesh sieve.

[0012] The stabilizer for heavy metals and phosphorus in eutrophic water bodies is preferably 313.3-460 g of bentonite, 460-626.7 g of medical stone, 20-40 g of molybdic acid and 20-80 g of biochar.

[0013] The preparation method of the above-mentioned stabilizer comprises the following steps: taking modified alkalized bentonite and acid-modified medical stone and mixing them evenly, then adding molybdate reagent and biochar, and mixing them thoroughly, and adding the following amounts of each substance: (i) adding alkalized modified bentonite and acid-modified medical stone in different proportions to each kilogram of material, preparing them in different proportions, and setting the mass ratio of alkalized bentonite: medical stone to 1:1, 1:2, 1:3, 2:1 or 3:1 respectively; (ii) adding different masses of molybdate reagent to each kilogram of material, including 2.5g, 5.0g, 10.0g, 20.0g or 40.0g; (iii) adding different masses of biochar to each kilogram of material, including 20g, 40g or 80g.

[0014] The stabilizer is used to remove heavy metals and phosphorus from eutrophic water.

[0015] The specific application plan is: add the stabilizer to the eutrophic water body polluted by heavy metals, use biochar as a carrier to suspend the stabilizer material in the water body, use modified non-metallic mineral materials to adsorb and complex the heavy metals fixed by molybdic acid in the water body, and at the same time use the adsorbed heavy metals and molybdic acid to stabilize the phosphorus element in the water body, forming a stable combined state and sinking to the bottom of the water.

[0016] Beneficial effects: Through ingenious design, the present invention achieves the synergistic effect among biochar, modified non-metallic mineral materials and molybdic acid, significantly improving the stabilization treatment effect of heavy metals and phosphorus in eutrophic water. Specifically, the present invention cleverly uses biochar as a carrier and accurately controls its dosage, so that the composite material can be evenly suspended in the water. This design not only optimizes the distribution of the material, but also enhances its contact efficiency with water pollutants.

[0017] As the core of adsorption and complexation, modified non-metallic mineral materials can efficiently capture heavy metal ions initially fixed by molybdate to form stable complexes. At the same time, the heavy metals adsorbed in this process and molybdate work together as a "bridge" to further stabilize the phosphorus in the water, and by forming bound precipitates that are difficult to dissociate, these pollutants are caused to settle to the bottom of the water, thereby greatly improving the overall stabilization efficiency of the stabilizer for phosphorus and heavy metals.

[0018] The core of the present invention lies in the synergistic mechanism among biochar, non-metallic mineral materials and molybdic acid. They cooperate with each other to not only promote the effective precipitation of heavy metals and phosphorus, but also achieve the complete removal of phosphorus and heavy metals from the water body through subsequent dredging operations. This innovative solution not only significantly improves the treatment efficiency, but also achieves deep purification of eutrophic water pollutants under the effect of synergistic enhancement, providing an efficient and stable solution for water body restoration and environmental protection, showing extremely high application value and environmental benefits. DETAILED DESCRIPTION

[0019] Embodiment 1:

[0020] (i) adding bentonite (alkalized modified) and medical stone (acidified modified) in different proportions to each kilogram of material, preparing in different proportions, and setting the mass ratio of alkalized bentonite: medical stone to 1:1, 1:2, 1:3, 2:1, 3:1 and other 5 ratio methods;

[0021] (ii) adding different masses of molybdic acid reagent per kilogram of material, including 2.5g, 5.0g, 10.0g, 20.0g, and 40.0g;

[0022] (iii) Different masses of biochar were added per kilogram of material, including 20 g, 40 g, and 80 g.

[0023] Table 1 Mass of different substances per kilogram of repair material

[0024]

[0025] A eutrophic lake water body polluted by heavy metal lead was selected for restoration experiment. The water surface area was 300 square meters and the average water depth was 2.5 meters. The initial lead content in the water was 0.062 mg / L and the total phosphorus content was 0.26 mg / L. For other heavy metals such as cadmium, chromium, nickel and copper, reagent addition was adopted. At the same time, experiments were carried out. 15 water samples were collected and placed in 15 circular plastic water containers with a height of 2.5 meters and a diameter of 1.2 meters. 0.04g of cadmium chloride, 0.57g of potassium dichromate, 0.25g of nickel chloride and 8.50g of copper nitrate were added respectively. Then, different proportions of stabilizers were added at 3kg / 100m 3 Spread it in a container filled with lake water, add aeration for 2 hours to mix it thoroughly, and the results of cadmium, chromium, nickel and copper were 0.0082mg / L, 0.074mg / L, 0.041mg / L and 1.42mg / L, respectively. After standing for 10 days, the total phosphorus, lead, cadmium, chromium, nickel and copper content in the water were tested. After an interval of 3 months, the total phosphorus, lead, cadmium, chromium, nickel and copper content in the water were tested again to obtain the comparative results of the restoration performance of heavy metals and phosphorus stabilizers in different water bodies. The results of total phosphorus and lead are shown in Table 2, and the data of cadmium, chromium, nickel and copper are shown in Table 3 and Table 4.

[0026] Table 2 Comparison of the restoration performance of heavy metal lead and phosphorus stabilizers in water bodies at different times after application of stabilizers

[0027]

[0028] Table 3 Comparison of cadmium, chromium, nickel and copper in polluted water after 10 days of application of stabilizer

[0029]

[0030]

[0031] Table 4 Comparison of cadmium, chromium, nickel and copper in polluted water after 30 days of application of stabilizer

[0032]

Claims

1. A stabilizer for heavy metals and phosphorus in eutrophic waters, characterized in that: The effective ingredients include bentonite, medical stone, molybdic acid and biochar, wherein the mass ratio of the bentonite to the medical stone is (1-3): (3-1), the content of molybdic acid is 2.5-40 g / kg, and the content of biochar is 20-80 g / kg.

2. The stabilizer for heavy metals and phosphorus in eutrophic waters according to claim 1, characterized in that: The bentonite is modified by alkalization.

3. The stabilizer for heavy metals and phosphorus in eutrophic waters according to claim 2, characterized in that: The alkalization modification step comprises: grinding bentonite and passing it through a 20-mesh sieve, mixing the sieved bentonite with a 0.20 mol / L potassium bicarbonate solution at a solid-liquid ratio of 1 g:10 mL, adjusting the pH value to 8.00 using potassium hydroxide or hydrochloric acid, stirring at room temperature and then centrifuging, filtering, drying the obtained bentonite at 60-80° C., and grinding until all the bentonite passes through a 200-mesh sieve.

4. The stabilizer for heavy metals and phosphorus in eutrophic waters according to claim 1, characterized in that: The medical stone is modified by acidification.

5. The stabilizer for heavy metals and phosphorus in eutrophic waters according to claim 4, characterized in that: The acidification modification step comprises: grinding the medical stone and passing it through a 20-mesh sieve, mixing the medical stone with a hydrochloric acid solution having a mass fraction of 10% at a solid-liquid ratio of 1g:10mL, stirring at 80°C, centrifuging and washing with deionized water until there is no chloride ion, removing the supernatant after centrifugation, drying the obtained medical stone at 60-80°C, and grinding until all the medical stone passes through a 200-mesh sieve.

6. The stabilizer for heavy metals and phosphorus in eutrophic waters according to claim 1, characterized in that: The bentonite is 313.3-460 g, the medical stone is 460-626.7 g, the molybdic acid is 20-40 g and the biochar is 20-80 g.

7. The method for preparing the stabilizer according to any one of claims 1 to 6, characterized in that: The steps are: take modified alkali-modified bentonite and acid-modified medical stone and mix them evenly, then add molybdate reagent and biochar, mix them thoroughly, and add the following amounts of each substance: (i) add different proportions of alkali-modified bentonite and acid-modified medical stone to each kilogram of material, prepare them in different proportions, and set the mass ratio of alkali-modified bentonite: medical stone to 1:1, 1:2, 1:3, 2:1 or 3:1 respectively; (ii) add different masses of molybdate reagent to each kilogram of material, including 2.5 g, 5.0 g, 10.0 g, 20.0 g or 40.0 g; (iii) add different masses of biochar to each kilogram of material, including 20 g, 40 g or 80 g.

8. Use of the stabilizer according to any one of claims 1 to 6 in removing heavy metals and phosphorus from eutrophic water.

9. The use according to claim 8, characterized in that: The stabilizer is added to the eutrophic water body polluted by heavy metals, and biochar is used as a carrier to suspend the stabilizer material in the water body. The modified non-metallic mineral material is used to adsorb and complex the heavy metals fixed by molybdic acid in the water body. At the same time, the adsorbed heavy metals and molybdic acid are used to stabilize the phosphorus element in the water body, forming a stable combined state and sinking to the bottom of the water.

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