A water quality conditioner containing modified sodium alginate, its preparation method and application

Abstract

The application relates to a water quality conditioner containing modified sodium alginate and a preparation method and application thereof, and belongs to the technical field of agricultural water treatment agents. The preparation method of the water quality conditioner containing modified sodium alginate provided in the application uses sodium alginate aldehyde, poly-gamma-glutamic acid, sodium alginate, carrageenan, phosphoric acid / phosphate and citric acid / citrate in cooperation, can be used for water quality adjustment and scale removal in large-scale planting drip irrigation belts, the oxidation degree level of the sodium alginate aldehyde is controlled by controlling the pH of the water quality conditioner, the stable scale removal effect is ensured, meanwhile, the water quality conditioner can also enter the soil together with drip irrigation water, adjusts alkaline soil, activates microbial flora, improves fertilizer utilization rate, has a promoting effect on the growth of crops, in addition, the water quality conditioner is a natural degradable component, cannot cause pollution and damage to the soil environment, conforms to the modern agricultural green environmental protection concept, and has important application value for agriculture, especially for the production operation mode of agricultural drip irrigation.

Description

Technical Field

[0001] This application relates to a water quality conditioner containing modified sodium alginate, its preparation method, and its application, belonging to the field of agricultural water treatment agent technology. Background Technology

[0002] Drip irrigation tape delivers water to the roots of crops through drippers or orifices on small-diameter capillary tubes for localized irrigation. This allows water to drip evenly and slowly into the soil near the crop roots, creating favorable conditions for high and stable crop yields. Drip irrigation tape is one of the most effective water-saving irrigation methods in arid and water-scarce regions, with a water utilization rate of up to 95%. It offers higher water-saving and yield-increasing effects than sprinkler irrigation and can be combined with fertilization to more than double fertilizer efficiency.

[0003] Currently, commonly used drip irrigation tape cleaning agents abroad include citric acid, perchloric acid, hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. Although these can prevent and dissolve scale to some extent, they seriously affect the physical and chemical properties of the soil, its aggregate structure, and its micro-ecological environment, thus impacting the normal growth of crops.

[0004] Sodium alginate, a representative of seaweed polysaccharides, is a natural water quality regulator. Seaweed polysaccharides, especially alginate from brown algae, are a class of natural macromolecular compounds rich in carboxyl groups. They can be used as thickeners, dispersants, emulsifiers, stabilizers, binders, film-forming agents, gelling agents, and ion exchangers, and are widely applied in various aspects of industrial and agricultural production. They can effectively improve crop resistance and rapid recovery after damage, and promote photosynthesis and crop vitality. In agriculture, seaweed polysaccharides are also used as stabilizers and fungicides in pesticides, enabling the effective utilization of pesticide components without causing environmental pollution, and also have a role in improving soil structure.

[0005] Existing technologies include publicly available reports on the application of sodium alginate in the removal of wastewater and heavy metals, such as "Preparation of Modified Sodium Alginate Gel Materials and Their Chromium Removal Performance" (Zhang Yujia, Wang Xingrun, Wang Lei, et al. Journal of Environmental Engineering Technology, 2023, 13(6): 2135-2142.) and "Research Progress on Wastewater Treatment Using Sodium Alginate and Its Derivative Materials" (Sun Shuang, Zhou Xing, Wang Guoxiu, et al. Progress in Analytical Chemistry, 2021, 11(1): 16-27). However, when sodium alginate is directly applied to drip irrigation tape as a cleaning agent, it is difficult to effectively remove dirt and deposits in the pipeline. This is because the common dirt and deposits in drip irrigation tape pipelines are organic residues and metal ions such as calcium and magnesium, which sodium alginate has limited removal effect on.

[0006] Poly-γ-glutamic acid (PGA) is a natural high-molecular-weight polymer composed of glutamic acid monomers linked by γ-amide bonds. It is a water-soluble, biodegradable polypeptide with excellent growth-promoting and stress-resistance activities for crops. It also promotes nutrient absorption by crop roots, improving fertilizer utilization. Furthermore, PGA exhibits various other activities, including adsorbing heavy metals, flocculating suspended solids, stabilizing pH, promoting the growth of beneficial microorganisms, reducing ammonia nitrogen and nitrite, and increasing dissolved oxygen.

[0007] Therefore, it is necessary to provide a regulator that can be used in drip irrigation tape to regulate water quality while efficiently removing dirt and sediment from pipes, suitable for large-scale drip irrigation tape planting scenarios. Summary of the Invention

[0008] To address the aforementioned issues, this application provides a water quality regulator containing modified sodium alginate, its preparation method, and its application. The water quality regulator provided can be used for water quality regulation and scale removal in large-scale planting drip irrigation tapes. It can also enter the soil along with the drip irrigation water to regulate alkaline soil, activate microbial communities, and improve fertilizer utilization, thus promoting crop growth. Furthermore, this water quality regulator is composed of natural and biodegradable components, which will not pollute or damage the soil environment, aligning with the modern agricultural green and environmentally friendly concept.

[0009] This application provides a method for preparing a water quality conditioner containing modified sodium alginate, characterized in that the preparation method includes the following steps: 1) Prepare a solution of poly-γ-glutamic acid; 2) Dissolve alginic acid in poly-γ-glutamic acid solution, adjust the pH to 2.0~6.0, and stir to dissolve alginic acid; 3) Add sodium alginate, carrageenan, phosphoric acid / phosphate and citric acid / citrate, then adjust the pH to 4.0±0.5, and continue stirring for 10~50 min to obtain the water quality conditioner.

[0010] Optionally, the water quality conditioner, by weight, comprises: 20-40 parts of alginate aldehyde, 10-20 parts of poly-γ-glutamic acid, 5-10 parts of sodium alginate, 5-10 parts of carrageenan, 1-2 parts of phosphoric acid / phosphate and 1-2 parts of citric acid / citrate.

[0011] Optionally, the molecular weight of the alginate aldehyde is 28-30 kDa; and / or, The molecular weight of the poly-γ-glutamic acid is 190~210 kDa.

[0012] Optionally, the oxidation degree of the alginic acid aldehyde is 55-65%.

[0013] Optionally, the mass ratio of alginate aldehyde to poly-γ-glutamic acid in the water quality conditioner is (1.8~2.2):1.

[0014] Optionally, the pH of the water quality conditioner is 4.0 ± 0.5.

[0015] Optionally, the preparation method of the alginate aldehyde includes the following steps: S1. Add sodium alginate to an organic solvent to prepare a suspension; S2. Stir the reaction after adding the oxidant; S3. Add ethylene glycol to terminate the reaction; S4. Add anhydrous ethanol for alcohol precipitation; S5. The precipitate obtained by filtration is alginic acid aldehyde.

[0016] Optionally, the oxidant in step 2) is selected from one or more of hydrogen peroxide, perborate, permanganate, and periodate; Preferably, the oxidant is sodium periodate.

[0017] Preferably, the weight ratio of sodium periodate to sodium alginate is 1:3.8~4.5.

[0018] Preferably, in step 2), the mixture is stirred at 80±5℃ for 60±10 min.

[0019] This application provides the application of the water quality conditioner prepared by the above-mentioned method containing modified sodium alginate in the removal of scale from drip irrigation tape and drip irrigation pipelines.

[0020] Optionally, the application includes the following steps: A) Turn on the drip irrigation pump switch and water valve to drip clean water for 0.5 to 1.0 hours; B) Add water to the fertilizer solution preparation tank / tank, measure the water quality conditioner according to the standard dosage of 2.5~3L / mu, and dissolve the water quality conditioner in the water; C) Turn off the clean water drip irrigation mode and switch to the fertilizer solution drip irrigation system. Use the solution in the fertilizer solution preparation tank / tank to clean the pipes to remove scale. D) After cleaning, let it stand for 0.5 to 1.0 hours, then use drip irrigation water to clean the pipes, and then close the drip irrigation and water pipe valves.

[0021] The water quality conditioner provided in this application can be used alone for cleaning drip irrigation tape and drip irrigation pipes. During use, the water quality conditioner is diluted. It should be noted that the pH change after dilution does not affect the descaling ability of the water quality conditioner. The pH of the water quality conditioner in this application is controlled within a certain range to avoid changes in the oxidation degree of alginic acid aldehyde, which would lead to a decrease in its descaling ability. pH control ensures the storage stability of the water quality conditioner.

[0022] Optionally, the application includes the following steps: a) Turn on the drip irrigation pump switch and water valve to drip clean water for 0.5 to 1.0 hours; b) Add water to the fertilizer solution preparation tank / tank that matches the planting area, measure the water quality conditioner according to the standard dosage of 2.5~3L / acre, and add it to the fertilizer solution preparation tank / tank. c) Stir to dissolve the water conditioner in water; d) Measure out water-soluble fertilizer according to the planting area and add it to the fertilizer solution preparation tank / tank. Stir until completely dissolved and the solution is uniform. e) Turn off the clean water drip irrigation mode and switch to the fertilizer solution drip irrigation system, using the solution in the fertilizer solution preparation tank / tank for fertilizer drip irrigation; f) After drip irrigation is completed, let it stand for 0.5 to 1.0 hours, clean the pipes with drip irrigation water, and then close the drip irrigation and water pipe valves.

[0023] To improve ease of use and the effectiveness of descaling the pipes, a water quality conditioner can be added to the fertilizer solution during drip irrigation. This avoids the need for separate drip irrigation, improving efficiency and saving steps. Furthermore, using the conditioner with the fertilizer solution can better reduce the formation of scale from calcium, magnesium, and protein in the fertilizer, preventing and treating scale formation at its source. It should be noted that the water quality conditioner described in this application can also be used alone to remove existing scale in drip irrigation pipes.

[0024] The beneficial effects of this application include, but are not limited to: 1. The water quality regulator containing modified sodium alginate according to this application, its preparation method and application, can be used for water quality regulation and scale removal in drip irrigation tapes for large-scale planting. At the same time, it can enter the soil along with the drip irrigation water, regulate alkaline soil, activate microbial communities, improve fertilizer utilization, and promote crop growth.

[0025] 2. According to the water quality conditioner containing modified sodium alginate of this application, its preparation method and application, sodium alginate can be oxidized by oxidants such as periodic acid to convert some hydroxyl groups in the uronic acid unit into aldehyde groups, which greatly improves its cross-linking activity with organic matter such as calcium and magnesium ions and proteins. The prepared alginate aldehyde strengthens the cross-linking reaction and metal ion complexation ability, and can better adsorb organic residues and metal ions such as calcium and magnesium in the drip irrigation tape pipeline, thereby better removing dirt and precipitates in the drip irrigation tape pipeline.

[0026] 3. The water quality conditioner containing modified sodium alginate according to this application, its preparation method and application, the prepared alginate aldehyde retains the biological activity of sodium alginate and has better degradation performance. It can self-degrade into small molecules in nature, which is environmentally friendly and more conducive to the absorption and utilization of crops, and can provide nutrients and stress resistance for crop growth.

[0027] 4. According to the modified sodium alginate water quality conditioner and its preparation method and application in this application, the ingredients of the conditioner in this scheme are all natural and biodegradable components, which will not cause pollution or damage to the soil environment and are in line with the concept of green and environmentally friendly modern agriculture. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a graph showing the effect of the water quality regulator involved in Example 4 of this application on tomato growth indicators; Figure 2 This is a graph showing the effect of the water quality regulator involved in Example 4 of this application on tomato fruit enlargement. Figure 3 This is a graph showing the effect of the water quality conditioner involved in Example 4 of this application on the color change of tomatoes; Figure 4 This is a graph showing the effect of the water quality regulator involved in Example 4 of this application on the quality of tomatoes. Detailed Implementation

[0029] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments. Unless otherwise specified, the raw materials and reagents in the embodiments of the present application are all purchased through commercial channels.

[0030] The present application solution will be described below through specific embodiments.

[0031] Example 1 Weigh 200g of sodium alginate and stir it in 500mL of anhydrous ethanol until it is evenly dispersed. Add 500mL of 10% sodium periodate aqueous solution. Stir and react at 80℃ for 1h, then add 18.5g of ethylene glycol to terminate the reaction. Add 5L of 95% ethanol to the reaction solution to precipitate alginate aldehyde. Filter the precipitate, wash and purify it with ethanol, and dry it in an oven at 40℃. Redissolve the obtained solid in a small amount of water, pass it through a dialysis membrane with a molecular weight cutoff of 1000Da to remove small molecule impurities, and dry it to obtain modified sodium alginate, which is alginate aldehyde.

[0032] Example 2 10g of the alginate aldehyde prepared in Example 1 was dissolved in 100mL of 5% poly-γ-glutamic acid solution. The pH was adjusted to 5.0 with KOH, and the mixture was stirred at room temperature for 15min. Then, 3.5g of sodium alginate, 3g of carrageenan, 0.8g of potassium dihydrogen phosphate and 0.6g of citric acid were added in sequence. The pH was adjusted to 4.0 with KOH, and the mixture was stirred for another 20min to obtain the water quality conditioner.

[0033] Example 3 A method for removing scale from drip irrigation tape and drip irrigation lines includes the following steps: 1) Turn on the drip irrigation pump switch and water valve to drip clean water for 0.5 to 1.0 hours; 2) Add water to the fertilizer solution preparation tank / tank that matches the planting area, measure the water quality conditioner according to the standard dosage of 2.5~3L / acre, and add it to the fertilizer solution preparation tank / tank; 3) Use a stirrer or wooden stick to dissolve the water conditioner evenly in the water; 4) Based on the planting area, measure an appropriate amount of water-soluble fertilizers containing macro-elements, add them to the fertilizer solution preparation tank / container, and stir until completely dissolved and the solution is uniform. 5) Turn off the clean water drip irrigation mode and switch to the fertilizer solution drip irrigation system for fertilizer drip irrigation; 6) After the fertilizer solution drip irrigation is completed, let it stand for 0.5 to 1.0 hours, then drip a small amount of clean water to clean the pipes. Then close the drip irrigation and water pipe valves to complete the removal of scale from the drip irrigation tape and drip irrigation pipes.

[0034] In one specific embodiment, the water quality conditioner was applied to the drip irrigation tape at a dosage of 2.5 L / acre, and applied three times consecutively. The calcium content of the water in the drip irrigation tape before and after application was measured, as shown in Table 1 below.

[0035] Table 1. Effect of water quality conditioners on the removal of calcium salts in drip irrigation tape

[0036] According to the results in Table 1, after three consecutive days of using the water quality conditioner, the calcium content in the drip irrigation tape decreased by 82.56%.

[0037] Example 4 Test product: Water quality conditioner (Example 2) Experimental crop: Tomato.

[0038] Trial period: May to June 2024.

[0039] Test location: Puji Town, Jiaozhou City, Qingdao.

[0040] Experimental treatment: as shown in Table 2 below.

[0041] Table 2 Specific settings for experimental treatment

[0042] During the tomato fruit expansion stage, root drip irrigation fertilization was carried out using 6000L of water, applied once every 8 days, for a total of 3 applications. Before the experiment, fruits of similar size were selected and marked. The experimental results and analysis are as follows: 1) Impact on tomato growth indicators Leaf color value and stem diameter are important indicators for measuring plant growth. At the end of the experiment, growth indicators were measured, and the results are as follows: Figure 1 As shown.

[0043] Depend on Figure 1 It can be seen that the leaf color value of T1 is 2.12 higher than that of CK, and the stem diameter of T1 is 2.22 mm larger than that of CK. Therefore, the addition of water quality conditioner has a better effect on promoting green leaves and strong seedlings.

[0044] 2) Effects on tomato fruit enlargement Fruit diameter and single fruit weight are important indicators for measuring fruit expansion. After three applications of fertilizer, the fruit diameter and single fruit weight were measured, and the experimental results are as follows: Figure 2 As shown.

[0045] Depend on Figure 2 It can be seen that the results for the transverse diameter and single fruit weight of tomato fruits were consistent, with T1 showing higher values ​​than CK, increasing the transverse diameter by 2.92 mm and the single fruit weight by 19.86 g. Therefore, under the conditions of this experiment, the T1 method with added water quality regulator showed a better fruit expansion effect than CK.

[0046] 3) Effect on tomato color change At the end of the experiment, the color-changing effects of each treatment were compared, and the results are as follows: Figure 3 As shown.

[0047] Depend on Figure 3It can be seen that CK contains 2 green fruits, 1 green-red fruit, and 3 light red fruits, while T1 contains 1 green fruit, 2 green-red fruits, and 2 light red fruits. T1 has a slightly better effect on promoting color change than CK. Therefore, this water quality regulator did not cause the fruit to ripen late due to promoting fruit enlargement.

[0048] 4) Impact on tomato quality Sugar content and firmness are important indicators for evaluating the quality of tomato fruits. At the end of the experiment, fruits with uniform ripeness were selected for sugar content and firmness measurement. The experimental results are as follows: Figure 4 As shown.

[0049] Depend on Figure 4 It can be seen that T1 has a better sweetening effect, with a sugar content increase of 1.4% compared to CK, and a higher nitrogen growth rate of 28.69%; T1 tomatoes also have higher firmness, increasing by 0.15*10 compared to CK. 5 Pa; therefore, T1's overall quality improvement effect is better than CK.

[0050] In summary, adding a water quality regulator when applying drip irrigation fertilizer to the roots during the fruit expansion stage of tomatoes can effectively improve the leaf color value, increase the stem thickness of the plant, and promote fruit enlargement, color change, and sweetness. It has a very good effect on promoting green leaves, strengthening seedlings, increasing yield, and improving quality.

[0051] Experimental Example 1 Before determining the final regulator scheme, the researchers conducted a comparative experiment on the selection of alginic acid aldehyde and poly-γ-glutamic acid. They found that the oxidation degree and molecular weight of alginic acid aldehyde, as well as the molecular weight of poly-γ-glutamic acid, all affect the regulator's scale removal effect. In particular, different oxidation degrees of alginic acid aldehyde showed significant differences in the regulator's scale removal effect.

[0052] To simulate the water quality in drip irrigation tape, 1 L of 2.05 g / L calcium nitrate solution, 1 L of 0.4 g / L magnesium nitrate solution, and 2 L of 0.8 g / L diammonium phosphate solution were added sequentially to the experimental container. A water quality conditioner diluted 2000 times was added to the container, and the mixture was stirred for 30 minutes. This process was repeated three times. The calcium and magnesium ion concentrations in the water were determined using atomic absorption spectrophotometry, and the pH value was measured using a pH meter. The results are shown in Table 1 below, and the differences in composition between the tested conditioner samples are shown in Table 3.

[0053] Table 3 Comparative experimental setup and descaling effect test results

[0054] According to the results in the table above, when alginic acid aldehyde with an oxidation degree of about 60% and a molecular weight of about 28.8 kDa is combined with poly-γ-glutamic acid with a molecular weight of about 200,000, the regulator product shows the best descaling effect, especially the oxidation degree of alginic acid aldehyde has a more obvious effect on descaling.

[0055] Experimental Example 2 The design concept of the regulator in this scheme is to remove scale through alginic acid aldehyde, and to achieve the dual effect of scale removal and water quality regulation by adding additives that promote plant growth and regulate water quality. In the specific scheme of this application, the researchers mainly used macromolecular polymers synthesized through bio-fermentation as the water quality regulator, specifically amino acid polymers. These amino acid polymers can regulate water quality while also promoting plant growth and providing stress resistance and other biological activities.

[0056] During the exploration of scale-removing agents, researchers found in the preliminary screening experiments that different amino acid polymers, when used as additives, showed different effects on scale removal when combined with alginic acid. In particular, when poly-γ-glutamic acid was used in combination with alginic acid, it not only had a better scale removal effect than alginic acid alone, but also had a better scale removal effect than other additives. It can be seen that poly-γ-glutamic acid and alginic acid showed a significant synergistic effect in scale removal. The test conditions and results are shown in Table 4.

[0057] Table 4. Descaling effects of different polymers combined with alginic acid aldehyde

[0058] According to the results in Table 4, poly-γ-glutamic acid and alginate aldehyde showed a significant synergistic effect in removing scale. It is speculated that poly-γ-glutamic acid can better assist in improving the cross-linking effect of alginate aldehyde with organic matter such as calcium, magnesium ions and proteins, thereby assisting in the removal of dirt and precipitates in drip irrigation tape pipes.

[0059] Experimental Example 3 The researchers had previously discovered that the oxidation degree of alginic acid aldehyde has a significant impact on the descaling effect of the regulator. The oxidation degree of alginic acid aldehyde mainly depends on its preparation method. Therefore, through repeated exploration, the researchers obtained a preparation method for a product with the required oxidation degree to prepare stable alginic acid aldehyde. The process conditions and oxidation degree results are shown in Table 5.

[0060] The method for detecting the degree of oxidation is as follows: The prepared crude alginate is dissolved in distilled water, hydroxylamine hydrochloride solution is added and reacted for 3 hours. NaOH is used as the titrant and the released equivalent amount of HCl is titrated by potentiometric titration. The concentration of aldehyde group in alginate (mol / g) is calculated from this, and then the degree of oxidation is calculated.

[0061] Table 5 Experimental results of the alginic acid aldehyde oxidation degree control process

[0062] During the use of scale-removing agents, field operators found that the longer the scale-removing agent was left, the worse its scale-removing effect became. Research revealed that the alginic acid aldehyde in the scale-removing agent was subject to self-degradation and excessive oxidation, both of which caused the scale-removing effect of the scale-removing agent to deteriorate with increasing storage time.

[0063] After research and experimentation, it was speculated that the problem might be caused by the pH of the regulator product being too low. To address this, the researchers explored suitable pH conditions for the regulator, investigated the stability and descaling effect of the regulator product, and tested the descaling effect of different pH products after 3 days, 14 days, and 30 days of use. The pH conditions and test results are shown in Table 6 below.

[0064] Table 6. pH of the regulator and its relationship to product stability and descaling effect.

[0065] According to the results in Table 6, adding KOH or NaOH to adjust the pH to around 4.0 at the end of the preparation of the regulator can ensure that the regulator has good stability and can maintain a good descaling effect even after 30 days. This can solve the problem of poor descaling effect caused by the self-degradation and excessive oxidation of alginic acid aldehyde.

[0066] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a water quality conditioner containing modified sodium alginate, characterized in that, The water quality conditioner comprises, by weight, 20-40 parts of alginate, 10-20 parts of poly-γ-glutamic acid, 5-10 parts of sodium alginate, 5-10 parts of carrageenan, 1-2 parts of phosphoric acid / phosphate and 1-2 parts of citric acid / citrate. The preparation method includes the following steps: 1) Prepare a solution of poly-γ-glutamic acid; 2) Dissolve alginic acid aldehyde in a poly-γ-glutamic acid solution, adjust the pH to 2.0~6.0, and stir to dissolve the alginic acid aldehyde. The oxidation degree of the alginic acid aldehyde is 55~65%. 3) Add sodium alginate, carrageenan, phosphoric acid / phosphate and citric acid / citrate, then adjust the pH to 4.0±0.5, and continue stirring for 10~50 min to obtain the water quality conditioner.

2. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 1, characterized in that, The molecular weight of the alginic acid aldehyde is 28~30 kDa; and / or, The molecular weight of the poly-γ-glutamic acid is 190~210 kDa.

3. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 1, characterized in that, The mass ratio of alginate aldehyde to poly-γ-glutamic acid in the water quality conditioner is (1.8~2.2):

1.

4. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 1, characterized in that, The preparation method of the alginic acid aldehyde includes the following steps: S1. Add sodium alginate to an organic solvent to prepare a suspension; S2. Stir the reaction after adding the oxidant; S3. Add ethylene glycol to terminate the reaction; S4. Add anhydrous ethanol for alcohol precipitation; S5. The precipitate obtained by filtration is alginic acid aldehyde.

5. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 4, characterized in that, In step S2, the oxidant is selected from one or more of hydrogen peroxide, perborate, permanganate, and periodate.

6. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 5, characterized in that, The oxidant is sodium periodate.

7. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 6, characterized in that, In the preparation method of the alginic acid aldehyde, the weight ratio of sodium periodate to sodium alginate is 1:3.8~4.

5.

8. The method for preparing the water quality conditioner containing modified sodium alginate according to claim 4, characterized in that, In step S2, the mixture is stirred at 80±5℃ for 60±10 min.

9. The application of the water quality conditioner prepared by the method of preparing the water quality conditioner containing modified sodium alginate as described in any one of claims 1 to 8 in removing scale from drip irrigation tape and drip irrigation pipelines.

10. The application according to claim 9, characterized in that, The application includes the following steps: A) Turn on the drip irrigation pump switch and water valve to drip clean water for 0.5 to 1.0 hours; B) Add water to the fertilizer solution preparation tank / tank, measure the water quality conditioner according to the standard dosage of 2.5~3L / mu, and dissolve the water quality conditioner in the water; C) Turn off the clean water drip irrigation mode and switch to the fertilizer solution drip irrigation system. Use the solution in the fertilizer solution preparation tank / tank to clean the pipes to remove scale. D) After cleaning, let it stand for 0.5 to 1.0 hours, then use drip irrigation water to clean the pipes, and then close the drip irrigation and water pipe valves.

11. The application according to claim 9, characterized in that, The application includes the following steps: a) Turn on the drip irrigation pump switch and water valve to drip clean water for 0.5 to 1.0 hours; b) Add water to the fertilizer solution preparation tank / tank that matches the planting area, measure the water quality conditioner according to the standard dosage of 2.5~3L / acre, and add it to the fertilizer solution preparation tank / tank. c) Stir to dissolve the water conditioner in water; d) Measure out water-soluble fertilizer according to the planting area and add it to the fertilizer solution preparation tank / tank. Stir until completely dissolved and the solution is uniform. e) Turn off the clean water drip irrigation mode and switch to the fertilizer solution drip irrigation system, using the solution in the fertilizer solution preparation tank / tank for fertilizer drip irrigation; f) After drip irrigation is completed, let it stand for 0.5 to 1.0 hours, clean the pipes with drip irrigation water, and then close the drip irrigation and water pipe valves.

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