Alkalinity slow-release material for promoting carbon sequestration and sink in marine artificial reefs and preparation method thereof

Abstract

The application discloses a kind of alkalinity slow-release materials and preparation method for promoting carbon sequestration and sink in marine artificial reef.The alkalinity slow-release material includes magnesium hydroxide, sodium carbonate, glutaraldehyde, cement, three light methyl aminomethylane buffer and water.Sodium carbonate, magnesium hydroxide and glutaraldehyde are mixed with cement, then water and three light methyl aminomethylane buffer are added for stirring.After sufficient stirring, the alkalinity slow-release material is obtained by setting and solidifying in a mold.The magnesium hydroxide and sodium carbonate of slow-release material react with free acid ions in water body to generate soluble salt that can be absorbed and salt that inhibits the growth of algae.The slow-release material increases the CO2 absorption capacity of water body and has no adverse effects on the environment.It can also be used to make artificial reefs, which can adjust the alkalinity of seawater and promote the growth of corals in addition to the function of transplantation and fixation.By using the slow-release material, the alkalinity of seawater can be maintained within a certain range, CO2 absorption and seawater acidification can be reduced, which is helpful for the recovery of coral reef community and promotes carbon sequestration and sink in seawater.

Description

TECHNICAL FIELD

[0001] The present application relates to the marine ecological environment, and in particular to a kind of marine artificial reef in promoting carbon sequestration alkalinity slow-release material and preparation method. BACKGROUND

[0002] Coral reef ecosystem is an important part of marine ecosystem, and is one of the highest biodiversity ecosystems. However, in recent decades, due to the emission of large amounts of greenhouse gases caused by human activities, the ocean absorbs a large amount of CO2, resulting in a decrease in seawater pH and a reconstruction of the carbonate system equilibrium. This leads to a slowdown in the calcification rate of a large number of reef-building corals around the world, and even a large-scale serious degradation of coral reefs. It is urgent to provide an artificial reef alkalinity slow-release material for the restoration of coral reef ecosystems. SUMMARY

[0003] The present application provides a kind of marine artificial reef in promoting carbon sequestration alkalinity slow-release material, to adjust the alkalinity and pH of seawater, increase the CO2 absorption capacity of water body, promote the growth and calcification of corals, and promote the carbon sequestration of marine ecology or coral reef ecosystem.

[0004] A first object of the present application is to provide a kind of marine artificial reef in promoting carbon sequestration alkalinity slow-release material, which comprises magnesium hydroxide, sodium carbonate, glutaraldehyde, cement, tris light methyl aminomethane buffer and water.

[0005] Preferably, the weight ratio of magnesium hydroxide, sodium carbonate, glutaraldehyde and cement is magnesium hydroxide:sodium carbonate:glutaraldehyde:cement = 1:1:1:2.

[0006] Preferably, the weight ratio of the magnesium hydroxide, sodium carbonate, glutaraldehyde, cement, tris light methyl aminomethane buffer and water is 1:1:1:2:1:5.

[0007] Preferably, the cement is portland cement.

[0008] Cement is used as a carrier material to fix magnesium hydroxide and sodium carbonate particles. Cement itself is also an alkaline material and can also play a partial adjustment role in seawater. Portland cement is made of limestone and clay as the main raw material, which is crushed, dosed and ground into raw material, then fed into a cement kiln to calcine into clinker, and then ground with a suitable amount of gypsum to form. Cement has the advantages of low price and easy availability, and is ideal for making slow-release materials.

[0009] A second object of the present application is to provide a method for the above-mentioned alkalinity slow-release material, which comprises the following steps: mixing sodium carbonate, magnesium hydroxide and glutaraldehyde with cement, adding water and tris light methyl aminomethane buffer, stirring, and then shaping and solidifying in a mold.

[0010] Preferably, the weight ratio of sodium carbonate, magnesium hydroxide, glutaraldehyde, cement, tris-methyl aminomethyl methane buffer, and water is 1:1:1:2:1:5.

[0011] A third object of the present application is to provide the use of the alkalinity slow-release material described above in adjusting the alkalinity and pH of a water body.

[0012] Preferably, the adjusting the alkalinity and pH of a water body is to reduce the CO2 content of the water body and inhibit the acidification of the water body.

[0013] Preferably, the water body is seawater.

[0014] The magnesium hydroxide and sodium carbonate are mixed with cement to make a composite alkaline material. According to different needs in the actual environment, the mixing ratio of cement, magnesium hydroxide, and sodium carbonate can be adjusted to adjust the slow-release effect, so as to achieve the target effect. After the material preparation, the magnesium hydroxide, sodium carbonate, glutaraldehyde, and cement are mixed in a weight ratio of 1:1:1:2, and water is added and stirred to make a new slow-release material. According to experimental measurements, in a 30L water body, using 200g of composite material, the efficacy of the composite material is about 3.5μmol / gt (t is 24h), and the sustained effect is more than four weeks, with a long duration. According to actual needs, the ratio of magnesium hydroxide, sodium carbonate, and cement can be adjusted to achieve the desired target.

[0015] A fourth object of the present application is to provide that the alkalinity slow-release material described above can be used as a material for making artificial reefs, providing a platform for coral transplantation and benthic organisms.

[0016] The beneficial effects of the present application are:

[0017] 1. By adjusting the proportion of cement, the properties after setting can be changed to adapt to different situations in the field environment.

[0018] 2. The ratio of magnesium hydroxide, sodium carbonate, and cement can be adjusted to control the slow-release rate and maintenance time of alkalinity. Sodium carbonate and magnesium hydroxide are used as slow-release agents to adjust the alkalinity. The alkalinity slow-release material containing magnesium hydroxide and sodium carbonate reacts with free acid ions in the environment in the field environment, gradually releases alkaline substances, increases the CO2 absorption capacity of the water body, generates soluble salts, and can continuously and slowly adjust the alkalinity of the surrounding environment, maintaining the acid-base homeostasis in the surrounding environment.

[0019] 3、Magnesium hydroxide, sodium carbonate and cement, biodegradability is good, and has less impact on the environment. The alkalinity release material has a longer action time, and the effect can be adjusted according to the proportion. The material is easy to obtain and easy to operate. After the action of the alkalinity release material is completed, an attachment platform can be provided for benthic organisms. Through the application of the release material, the alkalinity of seawater can be maintained within a certain range, CO2 and seawater acidification can be reduced, which is helpful for the recovery of coral reef community and promotes the carbon sequestration and carbon sink of seawater. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the appearance of the shaped alkalinity release material.

[0021] Figure 2 is the experimental system for conducting indoor simulation seawater system for release experiment.

[0022] Figure 3 is the comparison of the influence of sodium bicarbonate and sodium carbonate on the total alkalinity of seawater during the experiment, corresponding to the 6-day seawater total alkalinity change of group B and group C of example 3.

[0023] Figure 4 is the comparison of the influence of the material added with sodium carbonate on the total alkalinity of seawater during the experiment, corresponding to the 6-day seawater total alkalinity change of group D and group E of example 3.

[0024] Figure 5 is the comparison of the CO2 removal effect of the experimental group and the control group after the action of the alkalinity release material for 10 days. DETAILED DESCRIPTION

[0025] The following examples are further illustrations of the present application and are not intended to limit the present application.

[0026] Example 1: Preparation method of alkalinity release material

[0027] 1. Weigh magnesium hydroxide, sodium carbonate, glutaraldehyde and cement powder;

[0028] 2. Mix the materials according to the weight ratio of magnesium hydroxide:sodium carbonate:glutaraldehyde:cement powder = 1:1:1:2;

[0029] 3. Add the same weight of tris light methyl aminomethyl methane buffer as the weight of magnesium hydroxide in step 2, and mix and stir for about 30 minutes to make the materials fully mixed;

[0030] 4. Pour the stirred fluid material into a mold to shape;

[0031] 5. Dry the obtained composite material in a light-proof and dry environment for 5 days to make it completely solidified, and obtain the composite alkalinity release material as shown in Figure 1 .

[0032] Example 2: Practical application steps of alkalinity slow-release material

[0033] 1. Determine the amount of slow-release material used and the ratio of magnesium hydroxide and sodium carbonate in the slow-release material according to the seawater data of the actual environment and the adjustment target. Weigh 40g of magnesium hydroxide and 40g of sodium carbonate.

[0034] 2. Glutaraldehyde plays a role in inhibiting the growth of algae and adjusting pH. Weigh 40g of glutaraldehyde and 80g of cement powder.

[0035] 3. Mix magnesium hydroxide, sodium carbonate, glutaraldehyde, and cement powder, add 200g of water and 40g of trimethylaminomethane buffer, mix and stir, pour into a plastic mold, and dry in a light-proof and dry environment for 5 days to obtain the slow-release material.

[0036] 4. Then fix the slow-release material at the bottom of the seawater environment to allow it to react slowly.

[0037] Example 3: Comparison of alkalinity slow-release material ratio experiments

[0038] Select magnesium hydroxide, sodium bicarbonate, sodium carbonate, glutaraldehyde, trimethylaminomethane buffer, and cement to mix and match the materials. Select the appropriate material ratio to make the alkalinity slow-release material. The experiment was conducted in a simulated indoor system. Each group of materials was placed in a 30L seawater tank. The total alkalinity of the seawater in each group was measured every day for a total of 6 days.

[0039] Use different material ratios for the experiment and select the most ideal material ratio. The following is the material ratio grouping:

[0040] Group A uses cement, glutaraldehyde, and trimethylaminomethane buffer mixed with water. The weight ratio of cement: glutaraldehyde: trimethylaminomethane buffer: water is 2:1:1:2. Naturally air-dry to solidify and make alkalinity slow-release material.

[0041] Group B uses cement, sodium bicarbonate, glutaraldehyde, and trimethylaminomethane buffer mixed with water. The weight ratio of cement: sodium bicarbonate: glutaraldehyde: trimethylaminomethane buffer: water is 2:1:1:1:3. Naturally air-dry to solidify and make alkalinity slow-release material.

[0042] Group C uses cement, sodium carbonate, glutaraldehyde, and trimethylaminomethane buffer mixed with water. The weight ratio of cement: sodium carbonate: glutaraldehyde: trimethylaminomethane buffer: water is 2:1:1:1:3. Naturally air-dry to solidify and make alkalinity slow-release material.

[0043] Group D uses cement, magnesium hydroxide, glutaraldehyde, tris light methyl aminomethane buffer solution, and water to mix. The weight ratio of cement: magnesium hydroxide: glutaraldehyde: tris light methyl aminomethane buffer solution: water is 2:1:1:1:3. Let it dry naturally to make the alkalinity release material.

[0044] Group E uses cement, magnesium hydroxide, sodium carbonate, glutaraldehyde, tris light methyl aminomethane buffer solution, and water to mix. The weight ratio of sodium carbonate: magnesium hydroxide: glutaraldehyde: cement: tris light methyl aminomethane buffer solution: water is 1:1:1:2:1:5. Let it dry naturally to make the alkalinity release material.

[0045] After the experiment, the CO2 removal effect was compared. Except for scheme E, some of the ratios had poor material condensation effect and insignificant CO2 removal effect. The simulation system during the experiment is shown in Figure 2 . The effect of each group of materials on the total alkalinity of seawater after the experiment is shown in Figure 3 , 4 . Figure 3 The results show that sodium bicarbonate and sodium carbonate can both increase the total alkalinity of seawater during the experiment, but sodium carbonate has better effect. Therefore, sodium carbonate is selected as one of the components in the subsequent ratio. Figure 4 The results show that the experimental group with the addition of magnesium hydroxide and sodium carbonate has a stable effect on the total alkalinity of seawater and good effect.

[0046] In summary, we select the ratio of cement, sodium carbonate, magnesium hydroxide, glutaraldehyde, and tris light methyl aminomethane buffer solution to make alkalinity material. The selected ratio in the experiment is: the weight ratio of sodium carbonate: magnesium hydroxide: glutaraldehyde: cement: tris light methyl aminomethane buffer solution: water is 1:1:1:2:1:5. In actual operation, the ratio can be adjusted appropriately according to actual conditions and targets.

[0047] Example 4: Effect of alkalinity release material on removal of CO2 from seawater

[0048] 1. The alkalinity release material plate is made by the steps of example 1, as shown in Figure 1 .

[0049] 2. The experiment is carried out in an indoor simulation tank. Six experimental tanks are set up, each containing 30L of seawater. The experimental tanks are numbered in order as 1-6. Among them, 1, 2, and 3 are not placed with materials as blank controls, and 4, 5, and 6 are placed with the release material plate made in step 1. As shown in Figure 2 .

[0050] 3. Daily observation, recording, and photographing of the experimental system. Water samples were taken from the six experimental tanks at a fixed time of 9:00 AM each day, and the pH and total alkalinity of the blank group and the experimental group were measured respectively.

[0051] 4. The total duration of the experiment is set to 10 days, ending on the 10th day.

[0052] 5. Compare and analyze the CO2 removal effect of the experimental group with the control group after the experiment. Specific results are as follows: Figure 5 As shown.

Claims

1. An alkalinity-slow-release material for promoting carbon sequestration in marine artificial reefs, characterized in that, The mixture comprises magnesium hydroxide, sodium carbonate, glutaraldehyde, cement, tris(hydroxymethyl)aminomethane buffer solution, and water, wherein the weight ratio of magnesium hydroxide, sodium carbonate, glutaraldehyde, cement, tris(hydroxymethyl)aminomethane buffer solution, and water is 1:1:1:2:1:

5.

2. The alkalinity-sustaining material according to claim 1, characterized in that, The cement is silicate cement.

3. A method for preparing the alkalinity-controlled release material according to claim 1, characterized in that, The process includes the following steps: Sodium carbonate, magnesium hydroxide, and glutaraldehyde are mixed with cement, then water and tris(hydroxymethyl)aminomethane buffer are added and stirred. After thorough stirring, the mixture is shaped and solidified in a mold. The weight ratio of sodium carbonate, magnesium hydroxide, glutaraldehyde, cement, tris(hydroxymethyl)aminomethane buffer, and water is 1:1:1:2:1:

5.

4. The application of the alkalinity slow-release material according to claim 1 in adjusting the alkalinity and pH of water.

5. The application according to claim 4, characterized in that, The purpose of adjusting the alkalinity and pH of the water is to reduce the CO2 content of the water and inhibit water acidification.

6. The application according to claim 5, characterized in that, The water body is seawater.

7. The use of the alkalinity-slow-release material of claim 1 in promoting coral growth and calcification or providing an attachment platform for benthic organisms.

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