Acidified soil remediation material and preparation method thereof

Abstract

The present invention belongs to the technical field of soil remediation, and particularly relates to an acidified soil remediation material and a preparation method thereof, as well as a soil remediation method based on the acidified soil remediation material, wherein the acidified soil remediation material comprises combustion residues of bamboo processing waste, disodium ethylenediaminetetraacetic acid, potassium metasilicate and lignin sulfonate. The acidified soil remediation material and soil remediation method provided by the present invention can effectively improve the soil acidification and other problems of the bamboo shoot forest, and can effectively increase the bamboo shoot yield.

Description

Technical Field

[0001] The present invention belongs to the technical field of acidified soil remediation, and particularly relates to a bamboo forest-covered acidified soil remediation material and a preparation method thereof, as well as an acidified soil remediation method based on the acidified soil remediation material. Background Art

[0002] Phyllostachys praecox f.prevelnalis, also known as early bamboo, is a bamboo species for both shoots and materials belonging to the genus Phyllostachys in the subfamily Bambusoideae of the family Gramineae. Phyllostachys praecox is native to Zhejiang, Jiangxi and other places. Due to its early shoots, high yield and good economic benefits, it has been introduced and cultivated in large quantities as bamboo for shoots in recent years. Under natural conditions, Phyllostachys praecox produces a large number of shoots from March to April every year. However, due to the large number of shoots concentrated on the market in spring, the price of shoots is low, making it difficult to significantly improve the economic benefits of bamboo forests for shoots. In order to achieve better economic benefits, the technology of early shoot production by covering and warming in winter has been widely used in the management of Phyllostachys praecox forests. Studies have shown that in Hangzhou, northern Zhejiang, the coverage thickness of Phyllostachys lei dasyphylla is more than 40 cm. After covering, the time for bamboo shoots to emerge can be advanced by 4 months, from spring to early winter of the previous year; the coverage thickness of Phyllostachys lei dasyphylla forest in northern Jiangxi is more than 30 cm. After covering cultivation, the time for bamboo shoots to emerge can be advanced by 4 and a half months; the coverage thickness of Phyllostachys lei dasyphylla in Jianou and other places in northern Fujian is relatively thin, only about 25 cm, but due to its better water and heat conditions, the time for bamboo shoots to emerge is earlier than that in Zhejiang and Jiangxi, and the yield is higher.

[0003] In addition to increasing the amount of covering materials, the input of large amounts of excessive fertilizers is another important factor in promoting early and high yields of bamboo shoots. Studies have shown that in the process of managing bamboo shoot forests, some areas have applied fertilizers more than 15 times in a single season, and the amount of fertilizer applied is far higher than the growth demand of bamboo. Long-term, excessive, and blind fertilizer input directly causes a large amount of fertilizer to accumulate in the soil, which in turn causes problems such as soil quality degradation, bamboo forest degradation, and water pollution. Studies have shown that secondary disasters will occur within 10 years of continuous management of covered bamboo forests. At present, most of the bamboo forests with a planting time of more than 15 years, represented by Lin'an, Zhejiang, have experienced varying degrees of degradation, and soil acidification is the most important sign of bamboo forest soil quality degradation and bamboo forest degradation. Studies have shown that the accumulation of a large amount of base ions in the soil caused by excessive fertilization is the main factor affecting the growth of bamboo forests; other studies have pointed out that the management method that changes the growth law determines the occurrence of secondary disasters of bamboo. The occurrence of secondary disasters is the main reason for the reduction in yield and economic benefits of Leizhu forests. Therefore, acidification of soil, acidification regulation, pH rebalancing, and soil quality improvement are important measures to increase the yield of Leizhu forests and achieve sustainable development of bamboo forests. Summary of the invention

[0004] In order to overcome the defects of the above-mentioned prior art, the technical problem to be solved by the present invention is: to provide an acidified soil remediation material suitable for repairing the acidified soil of a bamboo shoot forest and a preparation method thereof, as well as an acidification remediation method based on the acidified soil remediation material.

[0005] In order to solve the above technical problems, the present invention provides an acidified soil remediation material, which includes combustion residues of bamboo processing waste, disodium ethylenediaminetetraacetic acid, potassium metasilicate and lignin sulfonate.

[0006] A method for preparing the aforementioned acidified soil remediation material is further proposed, comprising the following steps:

[0007] S1. prepare disodium edetate aqueous solution;

[0008] S2, adding the disodium ethylenediaminetetraacetic acid aqueous solution to the combustion residue, reacting at 50-60° C. for 24 hours under closed conditions to obtain an alkaline base material;

[0009] S3. Add lignin sulfonate and potassium metasilicate to the alkaline base material and mix them to obtain an acidified soil remediation material.

[0010] A soil remediation method based on the aforementioned acidified soil remediation material is further proposed, comprising the step of spreading the aforementioned acidified soil remediation material on the surface of the soil planted with Phyllostachys praecox to be remediated.

[0011] And the application of the aforementioned acidified soil remediation materials in remediating acidified soil in a bamboo shoot forest.

[0012] The beneficial effect of the present invention is that the acidified soil remediation material provided by the present invention can not only effectively neutralize the pH value of the soil of the bamboo shoot forest, but also effectively increase the bamboo shoot yield and improve the utilization rate of solid waste resources such as bamboo processing waste and its combustion residues. The experimental results show that after applying the acidified soil remediation material provided by the present invention, the bamboo shoot yield increased by 58% to 81% within 32 months, which is similar to the results of the existing soil restoration method. DETAILED DESCRIPTION

[0013] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes.

[0014] Acidified soil repair material, which includes combustion residues of bamboo processing waste, disodium ethylenediaminetetraacetic acid, potassium metasilicate and lignin sulfonate.

[0015] The combustion residue is mainly off-white and alkaline, and its main components include oxides and salts of Ca, Mg, K, Na, Si, P, Fe, and Al. The combustion residue is modified by disodium ethylenediaminetetraacetic acid to make it complex, thereby increasing its adsorption capacity for ions. In the actual processing process, the bamboo processing waste should be ground before modification, and the combustion residue should be sieved through a 100-mesh sieve to increase its surface area.

[0016] By adding lignin sulfonates, such as sodium lignin sulfonate, to the acidified soil remediation material, the fluidity and formability of the acidified soil remediation material can be improved. At the same time, lignin sulfonates can be used to improve the dispersibility of each component, and lignin sulfonates have certain wettability and complexing properties, thereby further improving the adsorption of a large number of ions in the soil by the acidified soil remediation material.

[0017] Potassium metasilicate can not only neutralize hydrogen ions in the soil, thereby improving the soil pH, but the orthosilicic acid formed after being neutralized by hydrogen ions can be directly absorbed and utilized by Phyllostachys praecox, thereby achieving the effect of promoting the growth of Phyllostachys praecox and increasing the yield of bamboo shoots.

[0018] Furthermore, the bamboo processing waste is selected from at least one of bamboo tips, bamboo branches, bamboo nodes, bamboo stumps and bamboo powder discarded in the bamboo processing process.

[0019] In one embodiment, the lignin sulfonate is prepared by acidification-sulfonation-conversion-distillation of black liquor remaining after bamboo papermaking pulping, or by existing methods, such as Hu Yongjun et al., Preparation of Modified Sodium Lignosulfonate Using Papermaking Black Liquor, Journal of Xinyang Normal University (Natural Science Edition), July 2004, Vol. 17. Of course, the lignin sulfonate can also be commercially available lignin sulfonate.

[0020] Furthermore, the aqueous solution of disodium ethylenediaminetetraacetate and the combustion residue constitute the alkaline base material of the acidified soil remediation material;

[0021] The mass ratio of the aqueous solution of disodium ethylenediaminetetraacetate in the alkaline base material to the combustion residue is (2-3):(8-12); preferably 3:10.

[0022] The concentration of the aqueous solution of disodium ethylenediaminetetraacetate is (4-7) g / 100 mL, preferably 5 g / 100 mL.

[0023] Furthermore, the mass ratio of the alkaline base material to the lignin sulfonate and potassium metasilicate is (18-20):(0.8-1.2):(0.8-1.2), preferably 18:1:1.

[0024] A method for preparing the aforementioned acidified soil remediation material comprises the following steps:

[0025] S1. prepare disodium edetate aqueous solution;

[0026] S2, adding the disodium ethylenediaminetetraacetic acid aqueous solution to the combustion residue, reacting at 50-60° C. for 24 hours under closed conditions to obtain an alkaline base material;

[0027] S3. Add lignin sulfonate and potassium metasilicate to the alkaline base material and mix them to obtain an acidified soil remediation material.

[0028] Specifically, firstly, a disodium ethylenediaminetetraacetic acid aqueous solution is prepared at a concentration of (4-7) g / 100 mL, and then the disodium ethylenediaminetetraacetic acid aqueous solution is added to the bamboo processing waste combustion residue, and the mass of the disodium ethylenediaminetetraacetic acid aqueous solution added is 30% of the weight of the bamboo processing waste combustion residue, and the bamboo processing waste combustion residue is modified to prepare an ethylenediaminetetraacetic acid salt mixture, and the temperature is kept constant at 50-60° C. for 24 hours under closed conditions to obtain an alkaline base material. Finally, the alkaline base material is mixed with lignin sulfonate and potassium metasilicate in a mass ratio of (18-20): (0.8-1.2): (0.8-1.2) to obtain an acidified soil remediation material.

[0029] The acidified soil remediation material is alkaline and contains ethylenediaminetetraacetic acid complex, oxides and salts of Ca, Mg, K, Na, Si, P, Fe, Al, potassium metasilicate, orthosilicic acid, etc. Therefore, it can not only effectively capture salt ions in the soil of the Phyllostachys praecox forest for shoots, thereby reducing the salt ion content in the soil, but also based on the silicon enrichment characteristics of Phyllostachys praecox, promote the absorption and utilization of silicon by Phyllostachys praecox, thereby promoting the growth of Phyllostachys praecox and the yield of shoots.

[0030] A soil remediation method based on the aforementioned acidified soil remediation material comprises the step of spreading the aforementioned acidified soil remediation material on the surface of the soil to be remediated where the pheasanthus praecox is planted.

[0031] Preferably, the acidified soil remediation material is spread at 0.45-0.6% of the weight of the soil per 20 cm depth.

[0032] The application of the above acidified soil restoration material in restoring acidified soil in a forest of Phyllostachys praecox shoots, wherein the soil in the forest of Phyllostachys praecox shoots has the problem of soil acidification or large accumulation of basic ions due to the abuse of the covering early shoot technology.

[0033] Example 1

[0034] A method for preparing an acidified soil remediation material comprises the following steps:

[0035] Prepare a disodium ethylenediaminetetraacetic acid aqueous solution at a concentration of 5g / 100mL, then add the disodium ethylenediaminetetraacetic acid aqueous solution to the bamboo processing waste combustion residue, the mass of the disodium ethylenediaminetetraacetic acid aqueous solution added is 30% of the weight of the bamboo processing waste combustion residue, modify the bamboo processing waste combustion residue to make an ethylenediaminetetraacetic acid salt mixed pulp, control the temperature to be constant at 55°C for 24 hours under closed conditions, and obtain an alkaline base material. Finally, the alkaline base material is mixed with lignin sulfonate and potassium metasilicate at a mass ratio of 18:1:1 to obtain an acidified soil remediation material.

[0036] Example 2

[0037] A method for preparing an acidified soil remediation material comprises the following steps:

[0038] Prepare a disodium ethylenediaminetetraacetic acid aqueous solution at a concentration of 5g / 100mL, then add the disodium ethylenediaminetetraacetic acid aqueous solution to the bamboo processing waste combustion residue, the mass of the disodium ethylenediaminetetraacetic acid aqueous solution added is 30% of the weight of the bamboo processing waste combustion residue, modify the bamboo processing waste combustion residue to make an ethylenediaminetetraacetic acid salt mixed pulp, control the temperature to be constant at 60°C for 24 hours under closed conditions, and obtain an alkaline base material. Finally, the alkaline base material is mixed with lignin sulfonate and potassium metasilicate at a mass ratio of 18:1:1 to obtain an acidified soil remediation material.

[0039] Experimental example

[0040] The experimental forest was selected from a Phyllostachys praecox cultivation area with a management time of more than 15 years. The Phyllostachys praecox cultivation area had suffered from soil acidification. Four experimental sites were set up in the experimental forest, and five experimental plots of 10m×10m were established in each experimental site. The soil weight at 20cm depth (2000000kg / hm 2 ) was added with the acidified soil remediation material prepared in Example 1 at 0%, 0.15%, 0.3%, 0.45% and 0.6%, and the specific dosage was 0 kg / hm 2 、3000kg / hm 2 、6000kg / hm 2 、9000kg / hm 2 and 12000kg / hm 2 , and are respectively recorded as treatment CK, treatment C-3000, treatment C-6000, treatment C-9000 and treatment C-12000.

[0041] The specific soil remediation method is: after the old bamboo is cut down in April, the acidified soil remediation material is evenly spread on the surface of the bamboo forest and deep plowed 20-30cm. During deep plowing, the bamboo whips should be retained as much as possible without destroying the original root whip system. The soil needs to be kept moist after deep plowing. If there is no rainfall in the short term, water needs to be added to the soil until the soil is soaked. Soil pH and bamboo shoot yield were tested and counted in the 8th, 20th and 32nd months of the experiment, respectively. The results are shown in Tables 1 and 2. Among them, this method is conducive to the timely reaction of potassium metasilicate with hydrogen ions in the soil to form orthosilicic acid, thereby promoting the enrichment, absorption and utilization of orthosilicic acid by Leizhu, thereby achieving the promotion of Leizhu production and bamboo shoot yield.

[0042] Table 1

[0043]

[0044]

[0045] Table 2

[0046]

[0047] As shown in Table 1, the pH of treatment CK was the lowest at different times. The application of acidified soil remediation materials had a significant effect on improving the soil pH of the Phyllostachys praecox forest, and with the increase in the application amount, the pH continued to increase. Eight months after application, that is, the soil pH in the bamboo shoot season of the year was between 5.46-7.27, with an average of 5.79. The results of the significant difference analysis showed that, except for treatments C-3000 and C-6000, there were significant differences among the other treatments (P<0.05).

[0048] 20 months after the application of acidified soil remediation materials, i.e., in the second bamboo shoot season, the results of soil pH measurement of different treatments showed that the soil pH of different treatments decreased, among which the CK treatment decreased the least, which was 0.9%, and the C-12000 treatment decreased the most, which was 19.2%, with an average decrease of 12.2%. This shows that with the increase of time, the remediation effects of different treatments are all decreasing, and the magnitude of the effect change is related to the application amount of acidified soil remediation materials. The results of significant difference analysis showed that 20 months after the application of acidified soil remediation materials, i.e., in the second bamboo shoot season after remediation, there was no significant difference in soil pH between treatments C-12000 and C-9000 (P>0.05), while there was still a significant difference in soil pH between C-9000 and other treatments. This shows that the acidified soil remediation materials still have a significant effect on the remediation of acidified soil 20 months after application.

[0049] 32 months after the application of acidified soil remediation materials, that is, in the third year of bamboo shoot season, the results of soil pH measurement in different treatments showed that the soil pH in different treatments continued to decline, among which the decline in CK treatment increased from 0.9% to 2.8%, and the decline in treatment C-12000 was still the largest, increasing from 19.2% to 32.5%, and the average decline increased from 12.2% to 19.8%. This shows that with the increase of time, the remediation effect of different treatments is still declining. Specifically, the soil pH of treatment CK is still the lowest, at 3.86. The soil pH of treatments C-12000 and C-9000 was 4.91. The results of significant difference analysis showed that there were significant differences between the treatments except between treatments C-12000 and treatment C-9000 (P<0.05).

[0050] As shown in Table 2, the shoot yield of treatment CK was the lowest at different times. The application of acidified soil remediation materials had a significant effect on increasing the shoot yield of Phyllostachys praecox forest. With the increase of application amount, the shoot yield increased first and then decreased. This was mainly due to the fact that when the application amount of acidified soil remediation materials increased to 12000 kg / hm 2 At that time, the soil pH of the bamboo shoot season was weakly alkaline, while the bamboo shoots of Phyllostachys praecox are suitable for neutral to slightly acidic soils, so the yield decreased. Specifically, 8 months after the application of acidified soil remediation materials, that is, the highest yield of the bamboo shoot season of the year was in treatment C-9000, and the lowest yield was in treatment CK, with bamboo shoot yields ranging from 21.0 to 33.2 t / hm 2 The average is 27.2t / hm 2 The results of the significant difference analysis showed that, except for treatments C-3000 and C-12000, there were significant differences among the other treatments (P<0.05).

[0051] 20 months after the application of acidified soil remediation materials, the results of the measurement of bamboo shoot yields in different treatments in the second year of bamboo shoot season showed that the bamboo shoot yields of treatments C-12000 and C-9000 increased by 22.6% and 0.6%, respectively. This was mainly because the soil pH of treatment C-12000 had become slightly acidic 20 months after the application of acidified soil remediation materials, which was more suitable for the growth of Phyllostachys praecox and promoted the increase of Phyllostachys praecox yield, but the yield was still lower than that of C-9000. The bamboo shoot yields of treatments CK, C-3000 and C-6000 decreased by 12.5%, 25.5% and 11.2%, respectively. This shows that with the increase of time, the remediation effects of different treatments are declining, and the soil pH becomes acidic again, so the bamboo shoot yield decreases. Among the different treatments, the yield of C-9000 is still the highest, and the change is not large. The results of significance analysis showed that, except for the absence of significant difference in bamboo shoot yield between C-3000 and CK, there were still significant differences in bamboo shoot yield among different treatments (P<0.05), indicating that 20 months after the application of acidified soil remediation materials, that is, the second bamboo shoot season after remediation, the effect of acidified soil remediation materials on increasing bamboo shoot yield still existed and the effect was significant.

[0052] 32 months after the application of acidified soil remediation materials, i.e., in the third year of bamboo shoot season, the results of the measurement of bamboo shoot yields in different treatments showed that except for treatment C-12000, the bamboo shoot yields of different treatments all decreased, but except for C-6000, the bamboo shoot yields of other treatments did not change much compared with the yields in the second bamboo shoot season. At this time, the bamboo shoot yield of treatment C-9000 was still the highest. The results of the significant difference analysis showed that, except for the bamboo shoot yields between C-3000 and CK, there was still a significant difference in bamboo shoot yields between different treatments (P<0.05), indicating that the application of acidified soil remediation materials in treatments C-6000, C-9000 and C-12000 still had a significant effect on increasing bamboo shoot yields.

[0053] The above experimental results show that the acidified soil remediation material provided by the present invention can significantly improve the soil pH of the peacock bamboo forest where the secondary disaster of soil acidification occurs due to covering bamboo shoots, and the greater the application amount of the acidified soil remediation material, the greater the increase in soil pH. However, with the increase of time, the remediation effect gradually decreases.

[0054] At the same time, after 30 months of application of acidified soil remediation materials, the yield of bamboo shoots in different remediation treatment groups increased. 2 The bamboo shoot yield was the highest when the acidified soil remediation material was applied, and it was able to remain relatively stable during the three bamboo shoot seasons, and was significantly higher than that of the other treatment groups. 2 It is most suitable for soil restoration of acidified bamboo shoot forests and can significantly increase bamboo shoot yields.

[0055] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. Acidified soil remediation material, characterized in that: The acidified soil remediation material includes combustion residues of bamboo processing waste, disodium ethylenediaminetetraacetic acid, potassium metasilicate and lignin sulfonate; The main components of the combustion residue of the bamboo processing waste include oxides and salts of Ca, Mg, K, Na, Si, P, Fe, and Al; the bamboo processing waste is selected from at least one of bamboo tips, bamboo branches, bamboo joints, bamboo stumps, and bamboo powder discarded in the bamboo processing process; the bamboo processing waste is ground before combustion; the combustion residue needs to be sieved through a 100-mesh sieve before modification; The aqueous solution of disodium ethylenediaminetetraacetate and the combustion residue constitute the alkaline base material of the acidified soil remediation material; the mass ratio of the aqueous solution of disodium ethylenediaminetetraacetate and the combustion residue in the alkaline base material is (2-3):(8-12); the concentration of the aqueous solution of disodium ethylenediaminetetraacetate is (4-7) g / 100 mL.

2. The acidified soil remediation material according to claim 1, characterized in that: The mass ratio of the alkaline base material to the lignin sulfonate and potassium metasilicate is (18-20):(0.8-1.2):(0.8-1.2).

3. A method for preparing the acidified soil remediation material according to any one of claims 1 to 2, characterized in that: The steps include: S1. prepare disodium edetate aqueous solution; S2, adding the disodium ethylenediaminetetraacetic acid aqueous solution to the combustion residue, reacting at 50-60° C. for 24 hours under closed conditions to obtain an alkaline base material; S3. Add lignin sulfonate and potassium metasilicate to the alkaline base material and mix them to obtain an acidified soil remediation material.

4. A soil remediation method, characterized in that: The method comprises the step of spreading the acidified soil repair material according to any one of claims 1 to 2 on the surface of the acidified soil where the pheasanthus praecox is planted to be repaired.

5. The soil remediation method according to claim 4, characterized in that: The acidified soil repair material is spread at 0.45-0.6% of the weight of the soil at a depth of 20 cm.

6. Use of the acidified soil remediation material according to any one of claims 1 to 2 in remediating acidified soil in a Phyllostachys praecox forest.

7. The use of the acidified soil remediation material according to claim 6 in remediating acidified soil in a bamboo shoot forest, characterized in that: The soil of the bamboo shoot forest has the problems of soil acidification and large accumulation of basic ions caused by the covering early shoot technology.

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