CN-117535058-B - Application of heteropoly compound/PVA compound in sand water retention

Abstract

The invention discloses application of a heteropoly compound/PVA compound in sand water retention. The invention mixes polymer polyvinyl alcohol with Standberg type heteropoly compound or its derivative to prepare heteropoly compound/PVA compound for sand water retention. The heteropoly compound/PVA compound can remarkably improve the water and fertilizer retention capacity of sandy soil, has high adhesion capacity, can resist strong wind weather in arid areas, is not easy to blow off to lose the effect, and can not fly off the air to cause air particle pollution. The sand improving material after gradual dehydration forms a porous film on the surface of sand, maintains the ventilation and water permeability of soil, and has positive effect on repairing degraded soil in desert areas.

Inventors

• CHEN KUN
• YU QIANG
• LIU SHENGQIU
• ZHOU JUNYA
• Guo Muyun

Assignees

• 华南理工大学

Dates

Publication Date

20260505

Application Date

20220725

Claims (9)

1. 1. The application of the heteropoly compound/PVA compound in sand water retention is characterized in that the heteropoly compound/PVA compound is a jelly formed by compounding Standberg type heteropoly compound and/or derivatives thereof, PVA and water, wherein Standberg type heteropoly compound and/or derivatives thereof account for 20-60% of PVA dry weight, and the mass ratio of PVA to water is 1:7-21; The Standberg-type heteropoly compound is inorganic polyoxometalate, wherein the structural formula of anions is [ X 2 M 5 O 21～23 ] n- , wherein X= P, se or S, M=Mo or W, and cations are at least one of NH 4 + 、Na + and K + ; The Standberg type heteropoly compound derivative is an organic-inorganic hybrid compound formed by substituting part of hetero atoms and/or oxygen atoms in Standberg type heteropoly compound anions with organic ligands, wherein the organic ligand substituent is at least one of -HPO 3 、-CH 3 PO 3 、-C 2 H 5 PO 3 、-O 2 CCH 2 PO 3 and NH 3 C 2 H 4 PO 3 .
2. 2. The use of a heteropoly compound/PVA complex in soil water retention according to claim 1, wherein the Standberg type heteropoly compound or derivative thereof is at least one of K 4 [Se 2 Mo 5 O 21 ]、(NH 4 ) 4 [S 2 Mo 5 O 21 ]、K 4 [(HPO 3 ) 2 Mo 5 O 23 ] and (NH 4 ) 6 [P 2 Mo 5 O 23 ).
3. 3. The application of the heteropoly compound/PVA composite in sand water retention according to claim 1, wherein the average molecular weight of the PVA is 100000-150000, and the alcoholysis degree is more than or equal to 98%.
4. 4. The application of the heteropoly compound/PVA composite in sand water retention according to claim 1, wherein the Standberg type heteropoly compound and/or the derivative thereof account for 40-60% of the dry weight of PVA, and the mass ratio of PVA to water is 1:10-21.
5. 5. The application of the heteropoly compound/PVA compound in sand water retention according to claim 1, wherein the heteropoly compound/PVA compound is a jelly prepared by compounding Standberg type heteropoly compound and/or a derivative aqueous solution thereof and PVA aqueous solution according to a volume ratio of 1:1-1:9.5, wherein the concentration of Standberg type heteropoly compound and/or a derivative aqueous solution thereof is 0.12-0.4 g/mL, and the mass percentage of PVA in the PVA aqueous solution is 5-15%.
6. 6. The use of a heteropoly compound/PVA composite according to claim 5 in soil conservation, wherein the heteropoly compound/PVA composite is obtained by uniformly mixing an aqueous solution of Standberg-type heteropoly compound and/or its derivative with an aqueous solution of PVA at room temperature and aging for 2-4 weeks.
7. 7. The application of the heteropoly compound/PVA composite in sand water retention according to claim 5, wherein the heteropoly compound/PVA composite is a jelly formed by compounding Standberg-type heteropoly compound and/or a derivative aqueous solution thereof and a PVA aqueous solution in a volume ratio of 1:9-9.5.
8. 8. The application of the heteropoly compound/PVA composite in sand water retention according to claim 5, wherein the PVA in the PVA aqueous solution accounts for 5-10% by mass; The concentration of the Standberg-type heteropoly compound and/or derivative aqueous solution is 0.3-0.4 g/mL.
9. 9. The application of the heteropoly compound/PVA composite in sand water retention according to claim 1, wherein the heteropoly compound/PVA composite and the sand are mixed uniformly according to a mass ratio of 1:10-1:20.

Description

Application of heteropoly compound/PVA compound in sand water retention Technical Field The invention belongs to the technical field of ecological restoration of soil degradation land, and particularly relates to application of a heteropoly compound/PVA (polyvinyl acetate) compound in sand water retention. Background China is one of the main arid countries in the world, the annual precipitation of arid-semiarid regions is low, the regional ecosystem is extremely fragile, and the land degradation phenomenon is serious. Land restoration in arid-semiarid regions is one of the key implementation projects of a series of ecological engineering in China. However, the land restoration of this area is still not ideal enough, and especially for arid areas, there are great challenges facing. Soil in arid regions, such as desert soil, is typically soil in the desert region, and is distributed in the Gansu river western corridor, the front plain of the Qili mountain in the western section, the northwest part of the inner Mongolia Erdos plateau, the south of the Xinjiang quasi-Song basin, the front inclined plain on both the south and north foot of the Tianshan, the Jiangshun Gobi, the JiangGobi, and the like. These areas are extremely arid, and have no rain for some years or even for all years, with dryness >4, and the soil moisture is mainly evaporated. In addition to severe water starvation, there is also a cause of difficulty in soil remediation. The part of the land is in a drought and strong wind zone, fine soil substances formed by in-situ weathering are always blown away by wind, and the residual ground surface is mostly in the form of gravel and gravel power. The strong wind weather further causes the rapid loss of soil moisture, and due to drought and lack of water, the surface plants grow slowly, mainly comprise pulp, deep roots and drought-enduring half shrubs and shrubs, and are often distributed in a single plant or small cluster shape. The vegetation coverage rate in arid areas is extremely low, and plant residues are mineralized quickly, so that the accumulation of soil organic matters is very weak, and the humus layer is not obvious. Land degradation under the influence of climate change and human activity is a very serious global environmental problem. Repairing degraded land is critical to sustainable ecosystem management and socioeconomic development decisions. One of the problems to be solved in the soil restoration of arid areas is mainly focused on improving the water and fertilizer retention of sandy soil. Currently, the modifier for improving the water retention and fertilizer retention capacity of the aeolian sandy soil mainly comprises natural modifiers such as bentonite, synthetic modifiers and biological modifiers. The natural modifier comprises bentonite, crop straw, livestock manure, etc., the synthetic modifier comprises polyacrylamide, polyethylene glycol, urea-formaldehyde resin, polyvinyl alcohol resin, etc., and the biological modifier comprises microorganism, earthworm, etc. It is obvious that these modifiers have some theoretical and technical problems in practical application, such as large application amount, long application time and short duration, and problems of application mode, etc., so that the application of these modifiers in large-area popularization is limited. Disclosure of Invention In order to solve the defects and shortcomings of the prior art, the invention aims to provide application of a heteropoly compound/PVA composite in sand water retention. The invention adopts Standberg type heteropoly compound or derivative aqueous solution and macromolecule polyvinyl alcohol (PVA) aqueous solution to obtain heteropoly compound/PVA compound which can be used for sand water retention through physical mixing. The invention aims at realizing the following technical scheme: The application of the heteropoly compound/PVA compound in sand water retention is characterized in that the heteropoly compound/PVA compound is a jelly formed by compounding Standberg type heteropoly compound and/or derivatives thereof, PVA and water, wherein Standberg type heteropoly compound and/or derivatives thereof account for 20-60% of PVA dry weight, and the mass ratio of PVA to water is 1:7-21. Preferably, the Standberg-type heteropoly compound and/or derivative thereof accounts for 40-60% of the dry weight of PVA, and the mass ratio of PVA to water is 1:10-21. Preferably, the Standberg-type heteropoly compound is an inorganic polyoxometalate, the anionic formula in the structure of which is [ X 2M5O21～23]n-, wherein x= P, se or S, m=mo or W, and the cation is at least one of NH 4+、Na+ and K +. Preferably, the Standberg-type heteropoly compound derivative is an organic-inorganic hybrid compound formed by substituting part of hetero atoms and/or oxygen atoms in Standberg-type heteropoly compound anions with organic ligands, and the organic ligand substituent is at least one of -HPO3、-CH3PO3、-C2H5PO3、