Pollution blocking water permeable brick prepared based on biomass power plant ash and sludge-based biochar and preparation method of pollution blocking water permeable brick

Abstract

The invention discloses a pollution blocking water permeable brick prepared based on biomass power plant ash and sludge-based biochar and a preparation method of the pollution blocking water permeable brick. The pollution blocking water permeable brick is prepared from the following raw materials in parts by mass: 20 to 25 parts of biomass power plant ash, 3 to 6 parts of cement, 15 to 20 parts of sludge-based biochar, 15 to 20 parts of mineral powder, 35 to 45 parts of natural zeolite, 5 to 10 parts of sand and 10 to 40 parts of clay. The biomass power plant ash is biomass power plant ash residue, and the sludge-based biochar is a municipal sludge pyrolysis product. Biomass power plant ash and sludge-based biochar are used as main brick making raw materials, and the function of intercepting pollutants of the water permeable brick is achieved. The brick making raw materials are low in price and wide in distribution, low-cost preparation of the water permeable brick is achieved, the water permeable brick has the advantages of being stable in ecology, energy-saving, environmentally friendly and capable of achieving resource circulation, and meanwhile the problems of land resource waste and environmental pollution caused by solid waste accumulation are solved.

Description

Technical Field

[0001] The invention relates to the field of ecological environment protection, and in particular to a pollution-barrier permeable brick prepared based on biomass power plant ash and sludge-based biochar. Background Art

[0002] Permeable bricks have strong water permeability, air permeability and certain strength. The laying of permeable bricks can effectively maintain ecological balance, alleviate urban heat island effect, promote surface water circulation, etc. These functions can effectively manage urban rainwater, improve urban secondary human settlement environment problems, and achieve the benign development of human living environment. Therefore, they are often used as paving materials required for sponge city construction.

[0003] However, existing permeable bricks only have a water-permeable function and cannot intercept pollutants. Polluted water will enter the groundwater through the permeable bricks, causing groundwater pollution. Summary of the invention

[0004] The purpose of the present invention is to provide a pollution barrier permeable brick prepared based on biomass power plant ash and sludge-based biochar in order to solve the problem that existing permeable bricks cannot intercept pollutants.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a pollution barrier permeable brick prepared based on biomass power plant ash and sludge-based biochar, the raw materials of the pollution barrier permeable brick comprising: 20-25 parts by mass of biomass power plant ash, 3-6 parts by mass of cement, 15-20 parts by mass of sludge-based biochar, 15-20 parts by mass of mineral powder, 35-45 parts by mass of natural zeolite, 5-10 parts by mass of sand, and 10-40 parts by mass of clay; the biomass power plant ash is biomass power plant ash, and the sludge-based biochar is the pyrolysis product of municipal sludge.

[0006] Optionally, the sand is composed of fine sand, medium sand and coarse sand, wherein the fine sand accounts for 25-35 parts by mass, the medium sand accounts for 55-75 parts by mass, and the coarse sand accounts for 5-15 parts by mass.

[0007] Optionally, the natural zeolite has an average particle size of 0.9-1.5 mm and a specific surface area of ​​260-590 m 2 / g.

[0008] The present invention also provides a method for preparing the above-mentioned pollution barrier permeable brick, comprising the following steps:

[0009] Step S1, drying the clay and sieving it, then adding power plant ash, mineral powder, sludge-based biochar, natural zeolite, and sand, mixing and grinding evenly, and adding water to obtain a brick mixture;

[0010] Step S2, adding cement to the brick mixture prepared in step S1, mixing well, filling into a mold, and calcining to form the pollution barrier permeable brick.

[0011] Optionally, the sludge-based biochar is produced by pyrolysis and carbonization of municipal sludge.

[0012] Optionally, in step S2, the calcination pressure is 20-25 MPa.

[0013] Optionally, in step S2, the calcination temperature is 900°C.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The present invention uses sludge-based biochar as raw material. The sludge-based biochar has a porous structure, a large specific surface area, and negatively charged functional groups such as carboxyl and hydroxyl groups, which are beneficial to the adsorption of positively charged metals in pollutants, thereby achieving the effect of adsorbing and blocking pollutants.

[0016] (2) The present invention uses biomass power plant ash as raw material. The biomass power plant ash is rich in activated silicon oxide and activated aluminum oxide, which makes the biomass power plant ash easier to react with other substances and accelerates the reaction process of brick making.

[0017] (3) The biomass power plant ash of the present invention has a large specific surface area, high surface energy, and a low heavy metal dissolution rate, and will not cause secondary pollution to groundwater. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described below in conjunction with embodiments.

[0019] At present, the existing permeable bricks only have the function of water permeability and cannot intercept pollutants. After the polluted water passes through the permeable bricks, it will still cause water and soil pollution.

[0020] In order to solve the problem that existing permeable bricks cannot intercept pollutants, the present invention provides a pollution barrier permeable brick prepared based on biomass power plant ash and sludge-based biochar, the raw materials of the pollution barrier permeable brick include: 20-25 parts by mass of biomass power plant ash, 3-6 parts by mass of cement, 15-20 parts by mass of sludge-based biochar, 15-20 parts by mass of mineral powder, 35-45 parts by mass of natural zeolite, 5-10 parts by mass of sand, and 10-40 parts by mass of clay.

[0021] Sludge-based biochar is a carbon source with a porous structure. It has a large specific surface area and contains negatively charged functional groups such as carboxyl and hydroxyl groups, which are beneficial to the adsorption of positively charged metals in pollutants, thereby achieving the effect of adsorbing and blocking pollutants.

[0022] Biomass power plant ash is the ash residue from biomass power plants. It has a large specific surface area and high surface energy, and can adsorb and block pollutants such as heavy metals.

[0023] In addition, biomass power plant ash also contains rich functional substances:

[0024] (1) Biomass power plant ash is rich in activated silicon oxide and activated aluminum oxide, which makes biomass power plant ash easier to react with other substances and accelerates the reaction process of brick making.

[0025] (2) The ash from the biomass power plant contains a small amount of calcium sulfate, which can act as a flocculant to promote the bonding between the raw materials and improve the overall strength and durability of the bricks.

[0026] (3) The ash from biomass power plants contains a small amount of unburned carbon, which can be used as an internal combustion component to reduce the energy consumption required for brick sintering.

[0027] Furthermore, the heavy metal dissolution rate of ash from biomass power plants is low and will not cause secondary pollution to groundwater.

[0028] As shown in Table 1, the present invention uses the acetic acid buffer solution method to determine the heavy metal dissolution rate of biomass power plant ash. The results show that the heavy metal dissolution rate of biomass power plant ash is low and will not cause secondary pollution to groundwater.

[0029] Table 1 Detection of heavy metal dissolution rate in biomass power plant ash

[0030] type cadmium lead chromium arsenic Zinc Total content mg / kg / 83 109 30 1325 Acid washing dissolution mg / kg 12 35 22 15 450

[0031] Therefore, the present invention uses sludge-based biochar and biomass power plant ash as the main raw materials of permeable bricks, and can obtain permeable bricks that can absorb and block pollutants.

[0032] The present invention also provides a method for preparing the above-mentioned pollution barrier permeable bricks based on biomass power plant ash and sludge-based biochar, comprising the following steps:

[0033] Step S1, drying the clay and sieving it, then adding power plant ash, mineral powder, sludge-based biochar, natural zeolite, and sand, mixing and grinding evenly, and adding water to obtain a brick mixture;

[0034] In some embodiments, the sand in the above raw materials consists of fine sand, medium sand and coarse sand, the particle size of the fine sand is 0.125-0.25 mm, the particle size of the medium sand is 0.25-0.5 mm, and the particle size of the coarse sand is 0.5-1 mm.

[0035] In some embodiments, the natural zeolite in the above raw materials has an average particle size of 0.9-1.5 mm and a specific surface area of ​​260-590 m 2 / g.

[0036] In some embodiments, water acts as a dispersant in step S1 to make the raw materials uniformly mixed. The weight of water accounts for about 7%-15% of the raw materials for brick making.

[0037] In some embodiments, the sludge-based biochar is prepared by pyrolysis and carbonization of municipal sludge, and the preparation method is as follows:

[0038] After preliminary air drying of the sludge (water content of about 60%), the sludge was placed at 105±5°C for drying for 12 hours. The dried sludge was added to a carbonization furnace and heated to 500°C at a heating rate of 10°C / min under nitrogen conditions. After maintaining for 2 hours, the temperature was cooled to room temperature at the same rate to obtain the sludge-based biochar.

[0039] Step S2, adding cement to the brick mixture prepared in step S1, mixing well, filling into a mold, and calcining to form the pollution barrier permeable brick.

[0040] Example 1 Preparation method of pollution barrier permeable bricks based on biomass power plant ash and sludge-based biochar

[0041] This embodiment provides a method for preparing pollution barrier permeable bricks based on biomass power plant ash and sludge-based biochar, comprising the following steps:

[0042] Step S1, drying the clay at 100°C, cooling it to room temperature, and grinding it in a grinder through a 20-mesh sieve, then adding power plant ash, mineral powder, sludge-based biochar, natural zeolite, and sand, mixing and grinding evenly, and adding water to obtain a brick mixture;

[0043] Step S2, add the above-mentioned brick mixture into a mortar mixer, continue to add cement, stir for 15 minutes, fill the stirred mixture into a mold, dry the body, put it into a high-temperature furnace for calcination, the calcination temperature is 900°C, the calcination pressure is 20-25MPa, and discharge it after natural cooling to room temperature.

[0044] Example 2

[0045] This embodiment provides a pollution barrier permeable brick based on biomass power plant ash and sludge-based biochar. The raw materials of the pollution barrier permeable brick include: 25kg of power plant ash, 6kg of cement, 32kg of natural zeolite, 5kg of sand, 20kg of sludge-based biochar, 12kg of mineral powder, 12kg of clay, and 8kg of water. The average particle size of the natural zeolite is 1.3mm, and the specific surface area is 450m 2 / g. The molding pressure of the brick making process is 25MPa and the firing temperature is 900℃.

[0046] Example 3

[0047] This embodiment provides a pollution barrier permeable brick based on biomass power plant ash and sludge-based biochar. The raw materials of the pollution barrier permeable brick include: 22kg of biomass power plant ash, 5kg of cement, 35kg of natural zeolite, 6kg of sand, 18kg of sludge-based biochar, 14kg of mineral powder, 15kg of clay, and 7kg of water. The average particle size of the natural zeolite is 1.7mm, and the specific surface area is 350m 2 / g. The molding pressure of the brick making process is 25MPa and the firing temperature is 900℃.

[0048] Example 4

[0049] This embodiment provides a pollution barrier permeable brick based on biomass power plant ash and sludge-based biochar. The raw materials of the pollution barrier permeable brick include: 20kg of power plant ash, 6kg of cement, 40kg of natural zeolite, 5kg of sand, 13kg of sludge-based biochar, 17kg of mineral powder, 18kg of clay, and 9kg of water. The average particle size of the natural zeolite is 1.8mm, and the specific surface area is 450m 2 / g. The molding pressure of the brick making process is 25MPa and the firing temperature is 900℃.

[0050] Comparative Example 1

[0051] Purchased from Yancheng Qiangda New Building Materials Co., Ltd.

[0052] Table 2 Comparison of properties of permeable bricks

[0053] 28d compressive strength 28d flexural strength Permeability Heavy metal retention rate Example 2 40.5Mpa 7.5Mpa <![CDATA[7.1*10 -2 cm / s]]> 70％ Example 3 39.3Mpa 7.3Mpa <![CDATA[7.9*10 -2 cm / s]]> 60％ Example 4 42.7Mpa 8.1Mpa <![CDATA[6.3*10 -2 cm / s]]> 55％ Comparative Example 1 41.3Mpa 7.8Mpa <![CDATA[5.6*10 -2 cm / s]]> 36％

[0054] It can be seen from Table 2 that, compared with Comparative Example 1, the water permeability of the permeable bricks of the present invention is greatly improved, and the pollutant retention rate is significantly improved, which can reach more than 70%; the compressive strength and flexural strength are not much different from the properties of ordinary finished permeable bricks.

[0055] The present invention adjusts the raw materials for firing permeable bricks, and uses biomass power plant ash and sludge-based biochar as the main raw materials for making bricks, so as to achieve the function of permeable bricks to intercept pollutants. The raw materials for making bricks of the present invention are low-priced and widely distributed, and low-cost preparation of permeable bricks is achieved, which has the characteristics of stabilizing ecology, energy conservation and environmental protection, and resource recycling, and at the same time solves the problems of waste of land resources and environmental pollution caused by solid waste accumulation.

[0056] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A pollution barrier permeable brick prepared based on biomass power plant ash and sludge-based biochar, characterized in that: The raw materials of the pollution barrier permeable brick include: 20-25 parts by mass of biomass power plant ash, 3-6 parts by mass of cement, 15-20 parts by mass of sludge-based biochar, 15-20 parts by mass of mineral powder, 35-45 parts by mass of natural zeolite, 5-10 parts by mass of sand, and 10-40 parts by mass of clay; The biomass power plant ash is biomass power plant ash residue, and the sludge-based biochar is a product of municipal sludge pyrolysis.

2. The pollution barrier permeable brick according to claim 1, characterized in that: The sand is composed of fine sand, medium sand and coarse sand, wherein the fine sand accounts for 25-35 parts by mass, the medium sand accounts for 55-75 parts by mass and the coarse sand accounts for 5-15 parts by mass.

3. The pollution barrier permeable brick according to claim 1, characterized in that: The natural zeolite has an average particle size of 0.9-1.5 mm and a specific surface area of ​​260-590 m 2 / g.

4. A method for preparing the pollution barrier permeable brick according to any one of claims 1 to 3, characterized in that: The steps include: Step S1, drying the clay and sieving it, then adding power plant ash, mineral powder, sludge-based biochar, natural zeolite, and sand, mixing and grinding evenly, and adding water to obtain a brick mixture; Step S2, adding cement to the brick mixture prepared in step S1, filling the mixture into a mold after mixing, and calcining to form the pollution barrier permeable brick.

5. The preparation method according to claim 4, characterized in that: The sludge-based biochar is prepared by pyrolysis and carbonization of municipal sludge.

6. The preparation method according to claim 4, characterized in that: In step S2, the calcination pressure is 20-25 MPa.

7. The preparation method according to claim 4, characterized in that: In step S2, the calcination temperature is 900°C.