Application of sea horse tooth biochar

Abstract

A preparation method of the biochar comprises the following steps: the initial temperature of a dried sea horse tooth stem is normal temperature, the temperature is raised to 180-220 DEG C at the temperature raising rate of 3-7 DEG C / min, the temperature is kept for 25-35 min, then the temperature is raised to 650-750 DEG C at the temperature raising rate of 3-7 DEG C / min, the temperature is kept for 100-140 min in a nitrogen atmosphere, the temperature is kept for 20-30 min, and the biochar is obtained. Finally, cooling to 100 DEG C or below at the cooling rate of 3 DEG C / min-7 DEG C / min, so as to obtain the sea horse tooth biochar. The highest removal rate of the sea horse tooth biochar on ammonia nitrogen in seawater reaches 59.9%.

Description

Technical Field

[0001] The invention relates to an application of seahorse teeth biochar. Background Art

[0002] Sesuvium portulacastrum is a fleshy herbaceous plant that grows on the seashore and is also a companion species of mangroves. It has a strong tolerance to salinity, drought and heavy metals, and can be widely used in sand fixation and embankment protection, soil and water conservation, and bioremediation of coastal wetlands. The species is classified as Equisetum, Magnoliales, Caryophyllales, Aizoaceae, and Sesuvium. Because of its strong vitality, it can continue to spread and form ground cover, making it a good plant for windbreak, sand fixation, and bank protection; it is also often planted on the banks of fish ponds, which can protect the banks on the one hand and provide shade for fish on the other hand. Its rotten leaves can also be eaten by fish; Sesuvium portulacastrum is also a good material for some birds to build nests.

[0003] Since seahorse teeth are perennial herb, and they are resistant to high salt and high temperature, reproduce quickly, survive easily, have controllable propagation, and have strong absorption capacity for elements such as C, N, and P, they have become ideal restoration plants for seawater environments and are widely used in artificial wetlands, ecological floating beds, and other marine environments, and in the restoration of aquaculture tailwater. However, how to deal with a large number of seahorse teeth after reproduction has become an urgent problem to be solved. Summary of the invention

[0004] The main purpose of the present invention is to provide the application of seahorse tooth biochar.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide an application of seahorse tooth biochar in removing ammonia nitrogen from seawater.

[0006] Another technical solution adopted by the present invention to solve its technical problem is: to provide an application of seahorse tooth biochar in adsorbing ammonia nitrogen in seawater.

[0007] Furthermore, the preparation method of the seahorse tooth biochar comprises the following steps: the initial temperature of the dried seahorse tooth stem is room temperature, the temperature is increased to 180°C to 220°C at a heating rate of 3°C / min to 7°C / min, maintained for 25min to 35min, then the temperature is increased to 650°C to 750°C at a heating rate of 3°C / min to 7°C / min, maintained for 100min to 140min in a nitrogen atmosphere, and finally the temperature is reduced to below 100°C at a cooling rate of 3°C / min to 7°C / min to obtain the seahorse tooth biochar.

[0008] Furthermore, the preparation of dried seahorse stems includes: removing leaves from the picked seahorses and leaving only stems, drying the stems, soaking the dried seahorses in pure water, and drying for later use.

[0009] Furthermore, the stems are cut into pieces of about 1 to 5 cm in length using scissors and dried.

[0010] Furthermore, the pure water soaking and drying are repeated 3 to 5 times, with each soaking lasting 24 hours to 72 hours.

[0011] Furthermore, the drying temperature is 30°C to 70°C.

[0012] Unless otherwise specified, the equipment, reagents, processes, parameters, etc. involved in the present invention are conventional equipment, reagents, processes, parameters, etc. and are not given as embodiments.

[0013] All ranges recited herein include all point values ​​within the range.

[0014] In the present invention, the "normal temperature" refers to the normal ambient temperature, which may be 10 to 30°C.

[0015] Compared with the background technology, this technical solution has the following advantages:

[0016] 1. Ammonia nitrogen in seawater is more difficult to remove than ammonia nitrogen in fresh water due to the salt effect. The present invention unexpectedly discovered that seahorse teeth made into biochar have a good removal effect on ammonia nitrogen in seawater.

[0017] 2. The seahorse tooth biochar prepared according to the optimal preparation method of the present invention has a maximum removal rate of 59.9% for ammonia nitrogen in seawater. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 This is a physical picture of the seahorse teeth that have not been soaked in water in Comparative Example 1.

[0020] Figure 2 This is a physical picture of the horsetooth biochar 500-Hmc in Comparative Example 2.

[0021] Figure 3 This is a physical picture of the seahorse tooth biochar 700-Hmc in Example 1.

[0022] Figure 4 This is a physical picture of the horsetooth biochar 700-Ca-Hmc in Comparative Example 3.

[0023] Figure 5 This is a physical picture of the walnut shell biochar Htk in Comparative Example 4.

[0024] Figure 6 This is a physical picture of the walnut shell biochar Ca-Htk in Comparative Example 5.

[0025] Figure 7This is a physical picture of the apricot shell biochar in Comparative Example 6.

[0026] Figure 8 This is a physical picture of the reed straw biochar 300-RSB in Comparative Example 7.

[0027] Fig. 9 This is a physical picture of the reed straw biochar 400-RSB in Comparative Example 8.

[0028] Fig.10 This is a physical picture of the reed straw biochar 500-RSB in Comparative Example 9.

[0029] Fig.11 This is a physical picture of the reed straw biochar 600-RSB in Comparative Example 10.

[0030] Fig.12 This is a physical picture of the reed straw biochar 700-RSB in Comparative Example 11.

[0031] Fig.13 It is the ammonia nitrogen removal rate of group B (Example 1) and group D (Comparative Example 3).

[0032] Fig.14 It is the ammonia nitrogen adsorption amount of group B (Example 1) and group D (Comparative Example 3).

[0033] Fig.15 It is the ammonia nitrogen removal rate of Group G (Comparative Example 4) and Group I (Comparative Example 5).

[0034] Fig.16 It is the ammonia nitrogen adsorption amount of Group G (Comparative Example 4) and Group I (Comparative Example 5).

[0035] Fig.17 It is the ammonia nitrogen removal rate of group A (comparative example 1) and group C (comparative example 2).

[0036] Fig.18 It is the ammonia nitrogen adsorption amount of group A (comparative example 1) and group C (comparative example 2). DETAILED DESCRIPTION

[0037] The raw materials of seahorse teeth come from the large diameter base of Fujian Marine Aquatic Seed Research Center. Production process: remove the leaves of the picked seahorse teeth and leave only the stems. Use scissors to cut the stems into about 3 cm lengths and dry them. Except for comparative example 1, soak the dried seahorse teeth in pure water for 48 hours, repeat the drying and soaking for 3 times, and dry them for later use. Comparative example 1 is directly dried for later use.

[0038] Comparative Example 1

[0039] Unmodified seahorse teeth heating program: put the seahorse teeth that have not been soaked in water after drying into a tube furnace, the initial temperature is room temperature, and the temperature is increased to 200℃ at a heating rate of 5℃ / min, and maintained for 30min, then increased to 700℃ at a heating rate of 5℃ / min, maintained for 120min under nitrogen atmosphere, and finally cooled to 100℃ at a cooling rate of 5℃ / min, and the program ends. Named A.

[0040] Comparative Example 2

[0041] 500-Hmc heating program: the initial temperature is room temperature, the temperature is increased to 200℃ at a heating rate of 5℃ / min, and maintained for 30min, then the temperature is increased to 500℃ at a heating rate of 5℃ / min, and maintained for 120min under nitrogen atmosphere, and finally the temperature is reduced to 100℃ at a cooling rate of 5℃ / min, and the program ends. Named C.

[0042] Example 1

[0043] 700-Hmc heating program: the initial temperature is room temperature, the temperature is increased to 200℃ at a heating rate of 5℃ / min, and maintained for 30min, then the temperature is increased to 700℃ at a heating rate of 5℃ / min, and maintained for 120min under nitrogen atmosphere, and finally the temperature is reduced to 100℃ at a cooling rate of 5℃ / min, and the program ends. Named B.

[0044] Comparative Example 3

[0045] 700-Ca-Hmc heating program: the mass ratio of dried seahorse teeth and oyster shell powder is 1:1, the initial temperature is room temperature, the temperature is increased to 200℃ at a heating rate of 5℃ / min, maintained for 30min, then increased to 700℃ at a heating rate of 5℃ / min, maintained for 120min under nitrogen atmosphere, and finally cooled to 100℃ at a cooling rate of 5℃ / min, and the program ends. Named D.

[0046] Comparative Example 4

[0047] Htk heating program: walnut shells with a particle size of 1-1.6 mm, the initial temperature is room temperature, the temperature is increased to 200°C at a heating rate of 5°C / min, maintained for 30 min, then increased to 700°C at a heating rate of 5°C / min, maintained for 120 min under a nitrogen atmosphere, and finally cooled to 100°C at a cooling rate of 5°C / min. The program ends and is named G.

[0048] Comparative Example 5

[0049] Ca-Htk heating program: walnut shells with a particle size of 1-1.6 mm and oyster shell powder were mixed in a mass ratio of 1:1 and then fired in a tube furnace at 700°C. The initial temperature was room temperature, and the temperature was increased to 200°C at a heating rate of 5°C / min, maintained for 30 minutes, then increased to 700°C at a heating rate of 5°C / min, maintained for 120 minutes in a nitrogen atmosphere, and finally cooled to 100°C at a cooling rate of 5°C / min, and the program ended. Named I.

[0050] Comparative Example 6

[0051] Heating program of apricot shell biochar: 6-12 mesh apricot shells were heated from room temperature to 500 °C at a heating rate of 5 °C / min, and heated at 500 °C in a nitrogen atmosphere for 120 min, and the program ended.

[0052] Comparative Example 7

[0053] 300-RSB: Reed straw biochar prepared at 300°C in a nitrogen atmosphere was heated to 300°C at a heating rate of 5°C / min at room temperature and heated at 300°C in a nitrogen atmosphere for 120 min, and the program ended.

[0054] Comparative Example 8

[0055] 400-RSB: Reed straw biochar prepared at 400℃ in nitrogen atmosphere, heated to 400℃ at room temperature at a heating rate of 5℃ / min, heated at 400℃ in nitrogen atmosphere for 120min, and the program ended.

[0056] Comparative Example 9

[0057] 500-RSB: Reed straw biochar prepared at 500°C in a nitrogen atmosphere was heated to 500°C at a heating rate of 5°C / min at room temperature and heated at 500°C in a nitrogen atmosphere for 120 min, and the program ended.

[0058] Comparative Example 10

[0059] 600-RSB: Reed straw biochar prepared at 600℃ in nitrogen atmosphere, heated to 600℃ at room temperature at a heating rate of 5℃ / min, heated at 600℃ in nitrogen atmosphere for 120min, and the program ended.

[0060] Comparative Example 11

[0061] 700-RSB: Reed straw biochar prepared at 700℃ in nitrogen atmosphere, heated to 700℃ at room temperature at a heating rate of 5℃ / min, heated at 700℃ in nitrogen atmosphere for 120min, and the program ended.

[0062] Nitrogen and phosphorus adsorption experiment of seahorse tooth biochar

[0063] Calculation method

[0064] (1) Removal rate

[0065] The removal rate calculation formula is as follows.

[0066]

[0067] In the formula: R1——removal rate (%)

[0068] C0——initial concentration (mg / L)

[0069] Ct——Concentration after t hours (mg / L)

[0070] (2) Adsorption capacity

[0071] The adsorption amount calculation formula is as follows.

[0072]

[0073] Where: q——adsorption capacity (mg / g);

[0074] V——sample volume (L);

[0075] C0——initial concentration (mg / L);

[0076] Ct——concentration after adsorption for t hours (mg / L);

[0077] m——Material quantity (g)

[0078] Ammonia nitrogen adsorption experiment of seahorse teeth and walnut shells: First, simulated seawater aquaculture tail water was prepared in the laboratory using the national standard substance for ammonia nitrogen (concentration: 1000 mg / L), 0.2g of each group of biochar was added to a conical flask, and 50ml of ammonia nitrogen solution (salinity 30) with a concentration of about 2mg / L was added, and shaken at 25°C and a shaking speed of 120r / min for 12h, and some water samples were taken for filtration and their ammonia nitrogen concentration was measured. The blank group was set up as follows: 50ml artificial seawater + biochar; the experimental group was set up as follows: 50ml ammonia nitrogen solution + biochar; the control group was set up as follows: 50ml ammonia nitrogen solution.

[0079] Ammonia nitrogen adsorption experiment of apricot shell and reed straw: First, simulated seawater aquaculture tail water was prepared in the laboratory using the national standard substance for ammonia nitrogen (concentration: 1000 mg / L), 0.05g of each group of biochar was added to a conical flask, and 50ml of ammonia nitrogen solution (salinity 30) with a concentration of about 1mg / L was added, and shaken at 25°C and a shaking speed of 120r / min for 12h, and some water samples were taken for filtration and the ammonia nitrogen concentration was measured. The blank group was set up as follows: 50ml artificial seawater + biochar; the experimental group was set up as follows: 50ml ammonia nitrogen solution + biochar; the control group was set up as follows: 50ml ammonia nitrogen solution.

[0080] according to Fig.13 and Fig.14 The ammonia nitrogen removal rate of group B reached 59.9%, and the ammonia nitrogen removal rate of group D was 9.3%, indicating that the adsorption of ammonia nitrogen by biochar is in a competitive relationship with Ca2+. The ammonia nitrogen binding sites on the surface of the modified seahorse tooth biochar are reduced, resulting in a decrease in the ammonia nitrogen adsorption effect.

[0081] like Fig.15 and Fig.16 The removal rates of ammonia nitrogen by group G and group I were 9.8% and 22.7% respectively, and the adsorption amounts were 0.052 mg / g and 0.12 mg / g respectively. The adsorption amount after modification was 2.31 times that before modification.

[0082] like Fig.17 and Fig.18 The removal rates of ammonia nitrogen in groups A and C were -3.4% and 8%, respectively, and the adsorption amounts were -0.0075mg / g and 0.017mg / g, respectively. The ammonia nitrogen adsorption effect of group B was also better than that of group C, so the ammonia nitrogen adsorption effect of seahorse teeth fired at 700℃ was better than that of seahorse teeth fired at 500℃. Soaking in pure water can soak the phosphates and ammonia nitrogen of the seahorse teeth that may cause water pollution into the water, reducing the substances that the seahorse teeth themselves may cause water pollution.

[0083]

[0084]

[0085] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the patent scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. Application of seahorse tooth biochar in removing ammonia nitrogen from seawater.

2. The use according to claim 1, characterized in that: The preparation method of the seahorse tooth biochar comprises the following steps: the initial temperature of the dried seahorse tooth rod is room temperature, the temperature is increased to 180°C to 220°C at a heating rate of 3°C / min to 7°C / min, maintained for 25min to 35min, then the temperature is increased to 650°C to 750°C at a heating rate of 3°C / min to 7°C / min, maintained for 100min to 140min in a nitrogen atmosphere, and finally the temperature is reduced to below 100°C at a cooling rate of 3°C / min to 7°C / min to obtain the seahorse tooth biochar.

3. The use according to claim 2, characterized in that: The preparation of dried seahorse stems comprises: removing leaves from the picked seahorses and leaving only stems, drying the stems, soaking the dried seahorses in pure water, and drying for later use.

4. The use according to claim 3, characterized in that: Use scissors to cut the stems into pieces of 1 to 5 cm in length and dry them.

5. The use according to claim 3, characterized in that: Repeat pure water soaking and drying 3 to 5 times, each soaking for 24h-72h.

6. The use according to claim 3, characterized in that: The drying temperature is 30℃~70℃.

7. Application of seahorse tooth biochar in adsorbing ammonia nitrogen in seawater.

8. The use according to claim 7, characterized in that: The preparation method of seahorse tooth biochar comprises the following steps: the initial temperature of the dried seahorse tooth stem is room temperature, the temperature is increased to 180°C to 220°C at a heating rate of 3°C / min to 7°C / min, maintained for 25min to 35min, then the temperature is increased to 650°C to 750°C at a heating rate of 3°C / min to 7°C / min, maintained for 100min to 140min in a nitrogen atmosphere, and finally the temperature is reduced to below 100°C at a cooling rate of 3°C / min to 7°C / min to obtain the seahorse tooth biochar.

9. The use according to claim 7, characterized in that: The preparation of dried seahorse stems comprises: removing leaves from the picked seahorses and leaving only stems, drying the stems, soaking the dried seahorses in pure water, and drying for later use.

10. The use according to claim 7, characterized in that: The stems are cut into pieces of 1 to 5 cm in length using scissors and dried; the pure water soaking and drying are repeated 3 to 5 times, with each soaking time of 24 to 72 hours; the drying temperature is 30 to 70 degrees Celsius.

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