Modified coal gangue ceramsite for removing phosphorus from eutrophic water body and preparation method of modified coal gangue ceramsite

Abstract

The invention relates to the technical field of water treatment, in particular to modified coal gangue ceramsite for dephosphorization of eutrophicated water and a preparation method thereof.The modified coal gangue ceramsite comprises, by weight, 71 parts of coal gangue, 6 parts of Fe2O3, 16 parts of Al2O3, 3.5 parts of K2CO3 and 3.5 parts of Na2CO3, the coal gangue comprises SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, P2O5 and SO3, the content of SiO2 in the coal gangue is 30%-60%, the content of SiO2 in the K2O in the coal gangue is 30%-60%, and the content of SiO2 in the K2O in the coal gangue is 30%-60%. The content of Al2O3 is 20%-40%; the particle size of the coal gangue ceramsite is 0.8-5 mm, the coal gangue ceramsite is formed through sintering, the sintering temperature of the coal gangue ceramsite is 1200 DEG C, and the sintering time is 90 min. The coal gangue ceramsite is modified and tested, the modified coal gangue ceramsite is diversified in variety, higher in adsorption capacity and higher in removal rate, and good pollutant treatment performance is kept by means of the structure, the inner hole structure and the property of the modified coal gangue ceramsite.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, in particular to a modified coal gangue ceramsite for removing phosphorus from eutrophic water and a preparation method thereof. Background Art

[0002] Coal has made a huge contribution to social and economic development. However, with the exploitation of coal resources, the collapse of goaf areas has caused the ground to sink. Under the influence of precipitation, groundwater and other factors, large areas of coal mining subsidence waters have been formed. Coal production has caused damage to the ecological environment of mining areas, especially the water quality of coal mining subsidence waters will be affected. Compared with natural lakes, subsidence waters are more likely to take in too many nutrients, resulting in excessive growth of algae, thereby destroying the ecological balance and causing eutrophication of water bodies. At the same time, phosphorus is a limiting factor for algal blooms. If algae are removed without managing phosphorus, large-scale algal reproduction may occur again. After removing phosphorus and algae from eutrophic water bodies, maintaining low phosphorus concentrations is an available strategy for long-term suppression of algal blooms;

[0003] A large amount of coal gangue is produced in the process of coal production and processing. If the coal gangue is abandoned, it will occupy a large amount of land and cause environmental pollution. Coal gangue ceramsite has a large specific surface area and good adsorption performance due to its unique surface structure, so it has broad application prospects in the field of water treatment.

[0004] Currently, most of the eutrophication of collapsed lakes is treated by adsorbents of high-concentration phosphate water bodies, but the phosphorus concentration of the water body during eutrophication is still at a relatively low concentration; therefore, it does not meet the existing needs. In this regard, we propose a modified coal gangue ceramsite for phosphorus removal from eutrophic water bodies and a preparation method thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a modified coal gangue ceramsite for removing phosphorus from eutrophic water bodies and a preparation method thereof, so as to solve the problem proposed in the above background technology that most of the existing eutrophication of collapsed lake water bodies is treated with adsorbents of high-concentration phosphate water bodies, while the phosphorus concentration of the water body during eutrophication is still at a relatively low concentration.

[0006] To achieve the above object, the present invention provides the following technical solution: a modified coal gangue ceramsite for phosphorus removal in eutrophic water, comprising coal gangue ceramsite, wherein the coal gangue ceramsite is composed of coal gangue, Fe 2 O 3 、Al 2 O 3 , K 2 CO 3 and Na 2 CO 3 Composition, by weight, 71 parts coal gangue, 6 parts Fe 2 O 3, 16 parts Al 2 O 3 , 3.5 parts K 2 CO 3 and 3.5 parts Na 2 CO 3 , the coal gangue includes SiO 2 、Al 2 O 3 , Fe 2 O 3 , CaO, MgO, Na 2 O.K 2 O.P 2 O 5 and SO 3 , the SiO in the coal gangue 2 The content is 30%-60%, Al 2 O 3 The content is 20%-40%.

[0007] Preferably, the particle size of the gangue ceramsite is 0.8-5 mm, and the gangue ceramsite is formed by sintering. The sintering temperature of the gangue ceramsite is 1200° C. and the sintering time is 90 min.

[0008] A method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water bodies comprises the following steps:

[0009] S1: Pretreatment of cleaning and drying, placing the gangue ceramsite on a sieve of not less than 19 mesh, using normal temperature and running clean water to vertically rinse the reciprocating vibrating sieve for 30 seconds, separating the gangue ceramsite from the sieve after rinsing and fully cleaning the sieve, using the sieve to rinse and filter the gangue ceramsite three times, then standing and preliminarily draining, and then spreading the gangue ceramsite in an oven, the thickness of the paving of the gangue ceramsite is not more than 20 mm, drying in an oven at 90°C for 2 hours, taking it out and standing to cool to room temperature;

[0010] S2: quantitative acidification treatment, taking 20g of the pretreated coal gangue ceramsite and soaking it in dilute hydrochloric acid for 24 hours, taking it out and washing it with pure water and measuring the pH value of the washed water, and drying the coal gangue ceramsite again in an oven after the pH value of the washed water becomes neutral to obtain acidified coal gangue ceramsite;

[0011] S3: Salt treatment, the acidified coal gangue ceramsite is placed in LaCl 3 In the solution, NaOH solution and dilute hydrochloric acid were used to react LaCl 3 The pH value of the solution was adjusted and LaCl 3The solution was placed under 25° C. and 180 rpm water conditions for 6 hours of shaking, and then the gangue ceramsite was washed with pure water and dried again in an oven to obtain acidified-salinated gangue ceramsite;

[0012] S4: calcination treatment, placing the acidified-salinated ceramsite in a muffle furnace at 300°C for calcination for 3 hours, wherein the heating rate of the muffle furnace is 6°C / min, and naturally cooling the acidified-salinated ceramsite after calcination in the muffle furnace to obtain acidified-salinated-calcined modified coal gangue ceramsite.

[0013] Preferably, the particle size of the coal gangue ceramsite in S1 is 0.8-3 mm, and the bulk density is 910 kg / m 3 , the apparent density is 1495kg / m 3 , the cylinder pressure strength is 15.6MPa.

[0014] Preferably, the particle size of the coal gangue ceramsite in S1 is 3-5 mm, and the bulk density is 920 kg / m 3 , the apparent density is 1561kg / m 3 , the cylinder pressure strength is 13.5MPa.

[0015] Preferably, the capacity of the dilute hydrochloric acid in S2 is 100 ml, the concentration of the dilute hydrochloric acid is 1 mol / L, and the dilute hydrochloric acid is used to soak the gangue ceramsite and dissolve surface impurities.

[0016] Preferably, the LaCl in S3 3 : The mass ratio of coal gangue to expanded clay is 1:5.

[0017] Preferably, the LaCl in S3 3 The pH value of the solution is 7.8-8.4, and the LaCl 3 The solution is used to attach the La ion product to the surface of the coal gangue ceramsite.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The invention modifies and tests the gangue ceramsite, and the modified gangue ceramsite has various types, stronger adsorption capacity and higher removal rate, and the adsorption amount of ammonia nitrogen, phosphorus, heavy metal ions and organic pollutants in domestic sewage and industrial wastewater is significantly increased. The modified material is prepared by using the gangue ceramsite, so that its own structure, internal pore structure and properties maintain good performance for pollutant treatment, which has economic benefits in water treatment and can provide reference significance for eutrophication control of water bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a line graph of the phosphate removal comparison experiment in Example 1 of the present invention;

[0021] Figure 2 It is a line graph of the comparative experiment of phosphate removal of Example 2 of the present invention and Comparative Examples 1 and 2;

[0022] Figure 3 is the EDS spectrum in Example 1 of the present invention;

[0023] Figure 4 The figure is a flow chart of the modification of the coal gangue ceramsite of the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] See also Figures 1 to 4 The present invention provides an embodiment: a modified coal gangue ceramsite for removing phosphorus from eutrophic water, comprising coal gangue ceramsite, wherein the coal gangue ceramsite is composed of coal gangue, Fe 2 O 3 、Al 2 O 3 , K 2 CO 3 and Na 2 CO 3 Composition, by weight, 71 parts coal gangue, 6 parts Fe 2 O 3 , 16 parts Al 2 O 3 , 3.5 parts K 2 CO 3 and 3.5 parts Na 2 CO 3 , coal gangue includes SiO 2 、Al 2 O 3 , Fe 2 O 3 , CaO, MgO, Na 2 O.K 2 O.P 2 O 5 and SO 3 , SiO in coal gangue 2 The content is 30%-60%, Al 2 O 3 The content is 20%-40%.

[0026] The particle size of the gangue ceramsite is 0.8-5 mm, and the gangue ceramsite is formed by sintering. The sintering temperature of the gangue ceramsite is 1200° C., and the sintering time is 90 minutes.

[0027] Embodiment 1:

[0028] A method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water bodies comprises the following steps:

[0029] S1: Pretreatment of cleaning and drying, placing the gangue ceramsite on a sieve of not less than 19 mesh, using normal temperature and running clean water to vertically rinse the reciprocating vibrating sieve for 30 seconds, separating the gangue ceramsite from the sieve after rinsing and fully cleaning the sieve, using the sieve to rinse and filter the gangue ceramsite three times, then standing and preliminarily draining, and then spreading the gangue ceramsite in an oven, the thickness of the paving of the gangue ceramsite is not more than 20 mm, drying in an oven at 90°C for 2 hours, taking it out and standing to cool to room temperature;

[0030] S2: quantitative acidification treatment, taking 20g of the pretreated coal gangue ceramsite and soaking it in dilute hydrochloric acid for 24 hours, taking it out and washing it with pure water and measuring the pH value of the washed water, and drying the coal gangue ceramsite again in an oven after the pH value of the washed water becomes neutral to obtain acidified coal gangue ceramsite;

[0031] S3: Salt treatment, the acidified coal gangue ceramsite is placed in a solution containing 5.3g LaCl 3 7H 2 O in 100 ml deionized water solution, use NaOH solution and dilute hydrochloric acid to react LaCl 3 The pH value of the solution was adjusted and LaCl 3 The solution was placed under 25° C. and 180 rpm water conditions for 6 hours of shaking, and then the gangue ceramsite was washed with pure water and dried again in an oven to obtain acidified-salinated gangue ceramsite;

[0032] S4: Calcination treatment, placing the acidified-salted ceramsite in a muffle furnace at 300°C and calcining for 3 hours, wherein the heating rate of the muffle furnace is 5°C / min, and naturally cooling the acidified-salted ceramsite after calcination in the muffle furnace to obtain acidified-salted-calcined modified coal gangue ceramsite.

[0033] The particle size of coal gangue ceramsite in S1 is 0.8-3mm, and the bulk density is 910kg / m 3 , the apparent density is 1495kg / m 3 , the cylinder pressure strength is 15.6MPa.

[0034] Furthermore, the capacity of the dilute hydrochloric acid in S2 is 100 ml, the concentration of the dilute hydrochloric acid is 1 mol / L, and the dilute hydrochloric acid is used to soak the gangue ceramsite and dissolve surface impurities.

[0035] LaCl in S3 3 : The mass ratio of coal gangue ceramsite is 1:5, LaCl3 The pH value of the solution is 8, LaCl 3 The solution is used to attach the La ion product to the surface of the coal gangue ceramsite.

[0036] Table 1

[0037]

[0038] See also Figure 3 As shown in Table 1, the modified coal gangue ceramsite subjected to acidification-salination-calcination was subjected to energy spectrum analysis, and an EDS spectrum was obtained. Table 1 is a table of energy spectrum analysis results of specific elemental components of the modified coal gangue ceramsite subjected to acidification-salination-calcination. The La element was introduced into the coal gangue ceramsite to improve its adsorption effect.

[0039] See also Figure 1 , the modified coal gangue ceramsite was tested for algae removal. The phosphate wastewater treated in the experiment was artificially prepared in the laboratory, which was close to the environmental concentration of coal mining subsidence area. The phosphate concentration was 0.2 mg / L and the pH value was 7±0.1. It was prepared on the spot each time. The amount of ceramsite added to each sample in the experiment was 10 g / L.

[0040] Depend on Figure 3 It can be seen that when the test time reaches 60 minutes, the phosphate removal rate of the modified coal gangue ceramsite reaches 30.27%. When the test time reaches 90 minutes, the phosphate removal rate of the modified coal gangue ceramsite reaches 60.92%. The modified ceramsite can significantly improve the phosphate removal rate and the adsorbed ceramsite is easy to recover.

[0041] Embodiment 2:

[0042] A method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water bodies comprises the following steps:

[0043] S1: Pretreatment of cleaning and drying, placing the gangue ceramsite on a sieve of not less than 19 mesh, using normal temperature and running clean water to vertically rinse the reciprocating vibrating sieve for 30 seconds, separating the gangue ceramsite from the sieve after rinsing and fully cleaning the sieve, using the sieve to rinse and filter the gangue ceramsite three times, then standing and preliminarily draining, and then spreading the gangue ceramsite in an oven, the thickness of the paving of the gangue ceramsite is not more than 20 mm, drying in an oven at 90°C for 2 hours, taking it out and standing to cool to room temperature;

[0044] S2: quantitative acidification treatment, taking 20g of the pretreated coal gangue ceramsite and soaking it in dilute hydrochloric acid for 24 hours, taking it out and washing it with pure water and measuring the pH value of the washed water, and drying the coal gangue ceramsite again in an oven after the pH value of the washed water becomes neutral to obtain acidified coal gangue ceramsite;

[0045] S3: Salt treatment: the acidified coal gangue ceramsite is placed in a solution containing 10.6 g LaCl 3 7H 2 O in 100 ml deionized water solution, use NaOH solution and dilute hydrochloric acid to react LaCl 3 The pH value of the solution was adjusted and LaCl 3 The solution was placed under 25° C. and 180 rpm water conditions for 6 hours of shaking, and then the gangue ceramsite was washed with pure water and dried again in an oven to obtain acidified-salinated gangue ceramsite;

[0046] S4: calcination treatment, placing the acidified-salinated ceramsite in a muffle furnace at 300°C for calcination for 3 hours, wherein the heating rate of the muffle furnace is 6°C / min, and naturally cooling the acidified-salinated ceramsite after calcination in the muffle furnace to obtain acidified-salinated-calcined modified coal gangue ceramsite.

[0047] The particle size of coal gangue ceramsite in S1 is 3-5mm, and the bulk density is 920kg / m 3 , the apparent density is 1561kg / m 3 , the cylinder pressure strength is 13.5MPa.

[0048] Furthermore, the capacity of the dilute hydrochloric acid in S2 is 100 ml, the concentration of the dilute hydrochloric acid is 1 mol / L, and the dilute hydrochloric acid is used to soak the gangue ceramsite and dissolve surface impurities.

[0049] Among them, LaCl in S3 3 : The mass ratio of coal gangue ceramsite is 1:5, LaCl 3 The pH value of the solution is 8, LaCl 3 The solution is used to attach the La ion product to the surface of the coal gangue ceramsite.

[0050] While the gangue ceramsite is modified in Example 2, a control example 1 is set up, and the phosphate removal rate of the modified gangue ceramsite prepared in Example 2 is compared with the phosphate removal rate of the modified ceramsite prepared in Control Example 1. The preparation method of Control Example 1 is different from that of Example 2 in that: in the salting of the gangue ceramsite, the pretreated ceramsite is added to the MgCl2 solution, that is, 33.83g of ferric chloride hexahydrate is weighed and dissolved in 100mL of deionized water with a pH value of 2, and other conditions such as the amount of reagents, the preparation steps and the ceramsite particle size used are the same as those in Example 1.

[0051] While the gangue ceramsite is modified in Example 2, a control example 2 is set up, and the phosphate removal rate of the modified gangue ceramsite prepared in Example 2 is compared with the phosphate removal rate of the modified ceramsite prepared in Control Example 2. The difference in the preparation method of Control Example 2 relative to Example 2 is that: in the salting of the gangue ceramsite, the pretreated ceramsite is added to the FeCl3 solution, that is, 19.32g of ferric chloride hexahydrate is weighed and dissolved in 100mL of deionized water with a pH value of 2, and other conditions such as the amount of reagents, the preparation steps and the ceramsite particle size used are the same as those in Example 2.

[0052] Table 2

[0053] Group Original ceramsite Example 2 Comparative Example 1 Comparative Example 2 Phosphate removal rate 15.03％ 76.79％ 23.37％ 63.44％

[0054] See also Figure 2 As shown in Table 2, the modified gangue ceramsite was subjected to algae removal test. The phosphate wastewater treated in the experiment was simulated wastewater prepared in the laboratory, which was close to the environmental concentration of the coal mining subsidence area. The phosphate concentration was 0.2 mg / L and the pH value was 7±0.1. It was prepared on the spot each time. The dosage of ceramsite for each sample in the experiment was 10 g / L.

[0055] The modified gangue ceramsite in Example 2 increases the phosphate removal rate by 61.76% compared with the original ceramsite, and compared with the modified gangue ceramsite prepared in Comparative Examples 1 and 2, the modified gangue ceramsite in Example 2 increases the phosphate removal rate by 53.42% and 13.35%, respectively. Modification of gangue ceramsite can significantly improve the removal rate of phosphate in subsidence waters.

[0056] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A modified coal gangue ceramsite for phosphorus removal in eutrophic water, characterized in that: The invention comprises gangue ceramsite, which is composed of gangue, Fe2O3, Al2O3, K2CO3 and Na2CO3, and comprises, by weight, 71 parts of gangue, 6 parts of Fe2O3, 16 parts of Al2O3, 3.5 parts of K2CO3 and 3.5 parts of Na2CO3. The gangue comprises SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, P2O5 and SO3. The content of SiO2 in the gangue is 30%-60%, and the content of Al2O3 is 20%-40%.

2. The coal gangue ceramsite according to claim 1, characterized in that: The particle size of the gangue ceramsite is 0.8-5 mm. The gangue ceramsite is formed by sintering. The sintering temperature of the gangue ceramsite is 1200° C. and the sintering time is 90 minutes.

3. A method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water, characterized in that: The following steps are involved: S1: Pretreatment of cleaning and drying, placing the gangue ceramsite on a sieve of not less than 19 mesh, using normal temperature and running clean water to vertically rinse the reciprocating vibrating sieve for 30 seconds, separating the gangue ceramsite from the sieve after rinsing and fully cleaning the sieve, using the sieve to rinse and filter the gangue ceramsite three times, then standing and preliminarily draining, and then spreading the gangue ceramsite in an oven, the thickness of the paving of the gangue ceramsite is not more than 20 mm, drying in an oven at 90°C for 2 hours, taking it out and standing to cool to room temperature; S2: quantitative acidification treatment, taking 20g of the pretreated coal gangue ceramsite and soaking it in dilute hydrochloric acid for 24 hours, taking it out and washing it with pure water and measuring the pH value of the washed water, and drying the coal gangue ceramsite again in an oven after the pH value of the washed water becomes neutral to obtain acidified coal gangue ceramsite; S3: salt treatment, placing the acidified gangue ceramsite in a LaCl3 solution, adjusting the pH value of the LaCl3 solution with a NaOH solution and dilute hydrochloric acid, and oscillating the LaCl3 solution at 25°C and 180rpm for 6 hours, then washing the gangue ceramsite with pure water and drying it in an oven again to obtain acidified-salinated gangue ceramsite; S4: calcination treatment, placing the acidified-salinated ceramsite in a muffle furnace at 300°C for calcination for 3 hours, wherein the heating rate of the muffle furnace is 6°C / min, and naturally cooling the acidified-salinated ceramsite after calcination in the muffle furnace to obtain acidified-salinated-calcined modified coal gangue ceramsite.

4. The method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water according to claim 3, characterized in that: The particle size of the coal gangue ceramsite in S1 is 0.8-3 mm, and the bulk density is 910 kg / m 3 , the apparent density is 1495kg / m 3 , the cylinder pressure strength is 15.6MPa.

5. The method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water according to claim 1, characterized in that: The particle size of the coal gangue ceramsite in S1 is 3-5 mm, and the bulk density is 920 kg / m 3 , the apparent density is 1561kg / m 3 , the cylinder pressure strength is 13.5MPa.

6. The method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water according to claim 1, characterized in that: The dilute hydrochloric acid in S2 has a capacity of 100 ml and a concentration of 1 mol / L. The dilute hydrochloric acid is used to soak the gangue ceramsite and dissolve surface impurities.

7. The method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water according to claim 1, characterized in that: The mass ratio of LaCl3 to coal gangue ceramsite in the S3 is 1:

5.

8. The method for preparing modified coal gangue ceramsite for phosphorus removal in eutrophic water according to claim 1, characterized in that: The pH value of the LaCl3 solution in the S3 is 7.8-8.4, and the LaCl3 solution is used to attach the product of La ions to the surface of the coal gangue ceramsite.

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