CN113800980A

CN113800980A - Soil conditioner prepared from industrial solid waste and application method thereof

Info

Publication number: CN113800980A
Application number: CN202111195345.3A
Authority: CN
Inventors: 朱晓波; 李望; 张传祥; 巩文辉; 燕旭东; 白雪雨; 邢宝林; 张治国; 聂彦合; 王强
Original assignee: Henan University of Technology
Current assignee: Henan University of Technology
Priority date: 2021-10-14
Filing date: 2021-10-14
Publication date: 2021-12-17

Abstract

A soil conditioner prepared by utilizing industrial solid wastes and an application method thereof are disclosed, the method comprises the steps of mixing, separating and culturing red mud, normal saline and a sterile culture medium to obtain alkali-resistant bacteria, crushing and grinding coal gangue, mixing, separating and culturing the coal gangue, the normal saline and the sterile culture medium to obtain acid-resistant bacteria, and then uniformly mixing the alkali-resistant bacteria, the acid-resistant bacteria and bacillus megatherium according to the mass ratio of 1: 1-3: 3-5 to obtain a composite strain; uniformly mixing the red mud and the ground coal gangue according to the mass ratio of 1: 1-4 to obtain composite industrial solid waste; and finally, uniformly mixing the composite strain, the composite industrial solid waste and the curing agent according to the mass ratio of 0.1-0.5: 100: 5-20, curing for 15-30 days to obtain the soil conditioner, and using the soil conditioner for planting crops to increase the yield of agricultural products such as corn, potato and the like by 10-30%. The invention has the advantages of high utilization rate of solid waste of the red mud and the coal gangue, simple preparation process of the soil conditioner, multiple bacterial types in the soil conditioner and strong synergistic effect, and can slowly release soil fertility, adjust soil pH value and improve soil microenvironment.

Description

Soil conditioner prepared from industrial solid waste and application method thereof

Technical Field

The invention belongs to the technical field of comprehensive utilization of industrial solid wastes, and particularly relates to a method for preparing a soil conditioner by utilizing industrial solid wastes.

Background

The red mud is strong alkaline solid waste discharged in the process of producing alumina from bauxite and can pollute the surrounding environment, so the comprehensive utilization of the red mud is widely concerned by researchers (summer sail, treishi, futilec, stayproc. the current situation of comprehensive utilization of red mud is reviewed in [ J ] China resource comprehensive utilization, 2021, 39(04): 85-89; Lixin. Red mud resource utilization and prospect [ J ] resource information and engineering, 2020, 35(03): 133-. At present, the comprehensive utilization direction of the red mud mainly comprises the following three aspects: the red mud is used for preparing building materials, the red mud is used for preparing adsorbing materials and extracting valuable components (Yan Yucai, common character, courage. research on red mud resource utilization [ J ] energy and environmental protection 2020, 42(10): 134) 138; Zhangxue, WangChongqing, Cao (east) research on soil remediation of red mud solid wastes [ J ] nonferrous metals (smelting part), 2021, 03): 84-92). Valuable components are extracted from the red mud, so that the resource recycling can be realized, and a certain amount of tailings or wastewater can be generated. The use of Red Mud for the production of Building Materials or adsorption Materials is technically feasible, but leads to "blooming" of the final product, affecting the strength and aesthetics of the product, due to the strong basicity of Red Mud (Ji, Z.Z., Zhang, Y.Y., Kai, W., et al. stable evaluation of basic resistance as a road material in specifications: A critical resistance Materials [ J ]. Construction and Building Materials, 2021, 270: 121419; Fei, L.L., Yue, H.H., Li, W., et al. Dekalization processes of basic resistance: A regenerative resistance Materials [ J ]. Journal of Materials, 2021, 403).

Coal gangue is carbonaceous rock discharged from coal mine in the production processes of development and excavation, coal mining, coal washing and the like, and is solid waste (Zhongnan, Yaoyan, Song Wei Jian, and the like. coal mine gangue treatment technical status quo and prospect [ J]The proceedings of mining and safety engineering 2020, 37(1): 136-. The stacking of the coal gangue not only occupies a large amount of land and destroys the ecological balance of the area, but also the spontaneous combustion of the gangue hill rich in sulfur can cause pollution to the atmosphere, water, soil and the like, thus being an environmental problem to be solved urgently (Yangye. the current situation of stacking and storing the coal gangue and the way of comprehensively utilizing the large amount of the coal gangue [ J]Chinese resource comprehensive utilization, 2014, 32(6): 18-22). Meanwhile, the coal mining causes the surface subsidence and serious ecological damage, and the coal mining damaged land area in China is about 90 hectares at present. Regarding the comprehensive utilization of coal gangue, the traditional treatment mode comprises the fields of extracting valuable components, preparing building materials and other materials, and the like, and in the process, the problems of high energy consumption, incapability of realizing clean production and generation of secondary pollutants still exist (Hu Yi. coal gangue treatment measures and utilization path analysis [ J)]Energy and energy conservation, 2019, (1) 74-75; research progress of coal gangue building material resource, Zhang Kai Feng, Wu Xiong, Yang Wen, etc. [ J]Material reports, 2013, 27(S1): 290-293; comprehensive utilization of coal gangue in cement industry [ J]Jiangxi building materials, 2019, 11: 6-8). The coal gangue contains main components of kaolinite, pyrophyllite, illite, limonite, anatase, albite and other minerals besides carbon, and not only contains a large amount of SiO₂The fertilizer also contains trace elements such as Fe, Mn, Mg, K, Cu, Zn, P and the like which are necessary for plant growth, is a basic ingredient for producing a soil conditioner, and fundamentally improves the comprehensive fertility of soil, thereby achieving the purpose of greatly improving the yield and the quality of agricultural products (bright field, Liouxiayan, Zhang Xun]Silicate notification 2015, 34(9): 2529-2533). However, the nutrient elements in the coal gangue mostly exist in the form of minerals, and natural weathering is difficult to be nutrient absorbed by plants in nature. In addition, the coal gangue contains a certain amount of sulfur-containing minerals such as pyrite and the like, so that the coal gangue is acidic, and the effect of the coal gangue in preparing the soil conditioner is also influenced.

Therefore, the current comprehensive utilization of the two solid wastes has the defects of low utilization rate of the solid wastes, high energy consumption in the utilization process, difficult operation, high difficulty in preparing soil conditioners, poor living environment of microorganisms, incapability of adjusting the pH value of soil and the like.

Disclosure of Invention

The invention aims to provide a method for preparing a soil conditioner by comprehensively utilizing red mud and coal gangue and an application thereof aiming at the defects in the prior art, and the method meets the characteristics of high utilization rate of solid waste of the red mud and the coal gangue, simple preparation process of the soil conditioner, multiple bacterial types and strong synergistic effect in the soil conditioner, capability of slowly releasing soil fertility, adjustment of soil pH value and improvement of soil microenvironment.

The object of the invention can be achieved by the following technical measures:

the method adopted by the invention comprises the steps of mixing, separating and culturing the red mud, the normal saline and the sterile culture medium to obtain alkali-resistant bacteria, crushing and grinding the coal gangue, mixing, separating and culturing the coal gangue, the normal saline and the sterile culture medium to obtain acid-resistant bacteria, and then uniformly mixing the alkali-resistant bacteria, the acid-resistant bacteria and the bacillus megaterium to obtain a composite strain; uniformly mixing the red mud and the finely ground coal gangue to obtain composite industrial solid waste; and finally, uniformly mixing and curing the composite strain, the composite industrial solid waste and the curing agent to obtain the soil conditioner. The soil conditioner is used for crop planting, and can increase the yield of agricultural products such as corn, potato and the like by 10-30%.

Specifically speaking: the method for preparing the soil conditioner by utilizing the industrial solid wastes comprises the following steps:

a. mixing red mud, normal saline and a sterile culture medium according to a mass ratio of 10-20: 70-100: 5-10, standing and culturing for 12-48 h at the temperature of 20-30 ℃, then performing solid-liquid separation to obtain a red mud leachate, and performing bacterial separation, acclimatization and culture on the red mud leachate to obtain alkali-resistant bacteria for later use;

b. crushing the coal gangue by a crusher until the granularity is less than 0.5mm, then grinding the crushed coal gangue in an ore grinding machine until the granularity is less than 0.045mm, and mixing the ground coal gangue, normal saline and a sterile culture medium according to the mass ratio of 10-20: 70-100: 5-10, standing and culturing for 12-48 h at the temperature of 20-30 ℃, then performing solid-liquid separation to obtain a coal gangue leachate, and performing bacterial separation, domestication and culture on the coal gangue leachate to obtain acid-resistant bacteria for later use;

c. uniformly mixing the alkali-resistant bacteria obtained in the step a, the acid-resistant bacteria obtained in the step b and bacillus megatherium according to the mass ratio of 1: 1-3: 3-5 to obtain a composite strain, and then uniformly mixing the red mud and the pulverized coal gangue with the particle size of less than 0.045mm according to the mass ratio of 1: 1-4 to obtain composite industrial solid waste for later use;

d. and c, uniformly mixing the composite strain, the composite industrial solid waste and a curing agent according to the mass ratio of 0.1-0.5: 100: 5-20, and curing for 15-30 days to obtain the soil conditioner (the soil conditioner can regulate the pH value of soil and slowly release fertilizer fertility such as nitrogen, phosphorus, potassium, carbon, silicon, iron, molybdenum and the like).

The sterile culture medium is an agar solid culture medium containing carbon, nitrogen, phosphorus and potassium.

The bacteria separation, domestication and culture processes adopt a plate streak inoculation method and a liquid culture medium inoculation method.

The red mud is Bayer process red mud, wherein the alkali content is 2-15%.

The coal gangue is solid waste discharged in the coal mining and coal dressing processes, and the sulfur content is 0.5-5%.

The curing agent is one or a mixture of a plurality of leaves, straws, pasture and weeds.

The application method of the soil conditioner prepared by the method of the invention is as follows: the soil conditioner is suitable for acid soil or saline-alkali soil, the application amount of the soil conditioner per mu is 100-200 kg, and the soil conditioner is used for planting corn and potato crops and can increase the yield of corn and potato agricultural products by 10-30%.

The invention has the following beneficial effects:

the method for preparing the soil conditioner by utilizing the two solid wastes of the red mud and the coal gangue, disclosed by the invention, not only improves the solid waste utilization rate of the red mud and the coal gangue, but also has the characteristics of simple preparation process of the soil conditioner, multiple bacterial types and strong synergistic effect in the soil conditioner, capability of slowly releasing soil fertility, regulation of soil pH value and improvement of soil microenvironment. The red mud is tailings obtained by high-temperature treatment of bauxite in a strong alkali medium, has strong basicity, is used for extracting, separating and culturing proper alkali-resistant bacteria, and is favorable for treating and improving saline-alkali soil.

Drawings

FIG. 1 is a process flow diagram of the present invention.

FIG. 2 shows the separation, culture and identification of alkali-resistant bacteria in red mud.

FIG. 3 is the separation, culture and identification of alkali-resistant bacteria in coal gangue.

FIG. 4 shows the appearance of Bacillus megaterium.

FIG. 5 shows the effect of bacteria liquid concentration and pH on the dissolution of the fertility element in soil amendment.

Detailed Description

The invention will be further described with reference to the following examples (FIG. 1):

in order to avoid duplicate descriptions, the technical parameters related to the embodiments of the present invention are described below in a unified manner: the bacteria separation, domestication and culture processes adopt a plate-streaking inoculation method and a liquid culture medium inoculation method, the red mud is Bayer process red mud, the alkali content is 2% -15%, the coal gangue is solid waste discharged in coal mining and coal dressing processes, the sulfur content is 0.5% -5%, and the curing agent is one or a mixture of a plurality of leaves, straws, pasture, weeds and the like. Details are not repeated in the specific embodiments.

Example 1

Mixing red mud, normal saline and a sterile culture medium according to a mass ratio of 10-15: 70-80: 5-8, standing and culturing for 12-24 hours at the temperature of 20-30 ℃, performing solid-liquid separation to obtain a red mud leachate, and performing bacterial separation, domestication and culture on the red mud leachate to obtain alkali-resistant bacteria for later use; crushing the coal gangue by a crusher until the granularity is less than 0.5mm, then grinding the crushed coal gangue in an ore grinding machine until the granularity is less than 0.045mm, and mixing the ground coal gangue, normal saline and a sterile culture medium according to a mass ratio of 20: 100:5, mixing, standing and culturing for 12-24 hours at the temperature of 20-30 ℃, then carrying out solid-liquid separation to obtain a coal gangue leachate, and carrying out bacterial separation, domestication and culture on the coal gangue leachate to obtain acid-resistant bacteria for later use; uniformly mixing alkali-resistant bacteria, acid-resistant bacteria and bacillus megatherium according to the mass ratio of 1: 1-3: 3-5 to obtain a composite strain, and uniformly mixing red mud and finely ground coal gangue according to the mass ratio of 1: 1-4 to obtain composite industrial solid waste for later use; uniformly mixing the composite strain, the composite industrial solid waste and the curing agent according to the mass ratio of 0.1-0.5: 100: 5-20, and curing for 15-20 days to obtain a soil conditioner; the acidic or alkaline soil and the soil conditioner are uniformly mixed according to the mass ratio of 100: 10-20 and are used for crop planting, the soil conditioner obtained by the invention can regulate the acidity of the soil, and can slowly release the fertility elements such as nitrogen, phosphorus, potassium, carbon, silicon, iron and the like, so that the corn and potato yield can be increased by 10-20%.

Example 2

Mixing red mud, normal saline and a sterile culture medium according to a mass ratio of 13-18: 80-90: 7-9, standing and culturing for 24-36 hours at the temperature of 20-30 ℃, performing solid-liquid separation to obtain a red mud leachate, and performing bacterial separation, acclimatization and culture on the red mud leachate to obtain alkali-resistant bacteria for later use; crushing the coal gangue by a crusher until the granularity is less than 0.5mm, then grinding the crushed coal gangue in an ore grinding machine until the granularity is less than 0.045mm, and mixing the ground coal gangue, normal saline and a sterile culture medium according to a mass ratio of 20: 100:5, mixing, standing and culturing for 24-36 h at the temperature of 20-30 ℃, then carrying out solid-liquid separation to obtain a coal gangue leachate, and carrying out bacterial separation, domestication and culture on the coal gangue leachate to obtain acid-resistant bacteria for later use; uniformly mixing alkali-resistant bacteria, acid-resistant bacteria and bacillus megatherium according to the mass ratio of 1: 1-3: 3-5 to obtain a composite strain, and uniformly mixing red mud and finely ground coal gangue according to the mass ratio of 1: 1-4 to obtain composite industrial solid waste for later use; uniformly mixing the composite strain, the composite industrial solid waste and the curing agent according to the mass ratio of 0.1-0.5: 100: 5-20, and curing for 20-25 days to obtain a soil conditioner; the acid or alkaline soil and the soil conditioner are uniformly mixed according to the mass ratio of 100: 10-20 and are used for crop planting, the soil conditioner can regulate the pH value of the soil, and slowly release the fertility elements such as nitrogen, phosphorus, potassium, carbon, silicon, iron and the like, so that the yield of agricultural products such as corn, potato and the like can be increased by 15% -25%.

Example 3

Mixing red mud, normal saline and a sterile culture medium according to a mass ratio of 17-20: 90-100: 8-10, standing and culturing for 36-48 h at the temperature of 20-30 ℃, performing solid-liquid separation to obtain a red mud leachate, and performing bacterial separation, domestication and culture on the red mud leachate to obtain alkali-resistant bacteria for later use; crushing the coal gangue by a crusher until the granularity is less than 0.5mm, then grinding the crushed coal gangue in an ore grinding machine until the granularity is less than 0.045mm, and mixing the ground coal gangue, normal saline and a sterile culture medium according to a mass ratio of 20: 100:5, mixing, standing and culturing for 36-48 h at the temperature of 20-30 ℃, then carrying out solid-liquid separation to obtain a coal gangue leachate, and carrying out bacterial separation, domestication and culture on the coal gangue leachate to obtain acid-resistant bacteria for later use; uniformly mixing alkali-resistant bacteria, acid-resistant bacteria and bacillus megatherium according to the mass ratio of 1: 1-3: 3-5 to obtain a composite strain, and uniformly mixing red mud and finely ground coal gangue according to the mass ratio of 1: 1-4 to obtain composite industrial solid waste for later use; uniformly mixing the composite strain, the composite industrial solid waste and the curing agent according to the mass ratio of 0.1-0.5: 100: 5-20, and curing for 15-30 days to obtain a soil conditioner; the acid or alkaline soil and the soil conditioner are uniformly mixed according to the mass ratio of 100: 10-20 and are used for crop planting, the soil conditioner can regulate the pH value of the soil, slowly release the fertilizer fertility of nitrogen, phosphorus, potassium, carbon, silicon, iron and the like in the soil, and can increase the yield of agricultural products such as corn, potato and the like by 20-30%.

Therefore, the specific embodiment has the characteristics of high solid waste utilization rate of the red mud and the coal gangue, simple preparation process of the soil conditioner, multiple bacterial types and strong synergistic effect in the soil conditioner, and can slowly release soil fertility, adjust the soil pH value and improve the soil microenvironment.

The isolation and morphological features of the alkali-resistant bacteria of the present invention are shown in FIG. 2.

As shown in FIG. 2(a), the bacteria separated from the red mud by drawing lines are few, which indicates that the strong alkaline solid waste is not suitable for the growth and propagation of microorganisms, and the red mud damming is hardly suitable for the growth of plants. As is clear from fig. 2(b), since the bacteria are spherical and distributed in a scattered manner, it is necessary to culture and acclimatize the bacteria in an enriched medium so as to satisfy the characteristic of rapid growth and propagation in an alkaline environment such as red mud, and to promote efficient release of the fertilizer elements such as potassium and iron in the red mud.

Because the coal gangue is tailings discharged in the mining and dressing process of coal mines, contains certain inorganic sulfur and organic sulfur and has certain acidity, the proper acid-resistant bacteria are extracted and separated from the coal gangue, the acid-resistant bacteria are favorable for treating and improving acid soil, and the separation and morphological characteristics of the acid-resistant bacteria are shown in figure 3.

As can be seen from FIG. 3(a), the bacteria separated from the coal gangue by drawing lines are more in number and good in growth state, which indicates that the weakly acidic environment of the coal gangue is suitable for the growth and propagation of microorganisms, and this is also a direct reason why the coal gangue is used as a raw material to prepare the soil conditioner. As can be seen from FIG. 3(b), the acid-fast bacteria are in the shape of a single rod and are densely and uniformly distributed, so that after being cultured and domesticated by using a conventional culture medium, the acid-fast bacteria can meet the characteristic of rapid growth and propagation in a coal gangue environment, and can promote the effective dissolution of the fertility elements such as phosphorus, carbon and the like in the coal gangue.

The bacillus megaterium is a relatively common strain and exists in a large amount in the soil, and the apparent appearance of the bacillus megaterium is shown in figure 4.

As can be seen from FIG. 4, the Bacillus megaterium belongs to multi-rod bacteria, which are mutually aggregated, and in a natural environment, the Bacillus megaterium has strong growth and reproduction capability and can effectively promote the decomposition of silicate, while the coal gangue and the red mud both contain a large amount of silicon oxides, and the synergistic effect of the three bacteria can not only promote the slow release of fertilizers such as phosphorus and potassium, but also enhance the effective dissolution of silicon fertilizers in two solid wastes and the absorption of plants.

The three bacteria are mixed according to a certain proportion to obtain mixed bacteria, the mixed bacteria are directly added into the solid waste, the concentration and the pH value of the bacteria liquid are examined, and the influence on the dissolution of phosphorus, potassium and silicon fertility elements in the coal gangue-red mud solid waste base soil conditioner is observed, and the result is shown in figure 5.

As can be seen from fig. 5(a), the effect of the concentration of the bacterial solution on the dissolution of phosphorus and silicon in the solid waste is relatively slow, and the dissolution rate of phosphorus and silicon increases slowly with the increase in concentration, indicating that minerals containing these two elements are relatively difficult to dissolve. The dissolution characteristics of potassium are that the concentration of the bacterial liquid is too high and the release of potassium is not facilitated due to the fact that the concentration of the bacterial liquid is increased firstly and then reduced. As can be seen from fig. 5(b), the dissolution law of the pH value for the three nutrient elements is that the dissolution rates of phosphorus, potassium, and silicon all tend to increase first and then decrease as the pH value increases from weak acidity to weak alkalinity, and the dissolution rates are highest in the neutral state of pH = 7. The composite bacteria in the invention comprise acid-resistant bacteria, alkali-resistant bacteria and bacillus megatherium, and have the capability of adjusting the pH value of soil, so that the pH value of the soil can be kept at about 7.0, the microenvironment of the soil can be improved, and the effective release of fertility elements such as phosphorus, potassium, silicon and the like is facilitated.

Therefore, the invention has the characteristics of high utilization rate of solid waste of the red mud and the coal gangue, simple preparation process of the soil conditioner, multiple bacterial types and strong synergistic effect in the soil conditioner, and can slowly release soil fertility, adjust soil pH value and improve soil microenvironment.

Claims

1. A method for preparing a soil conditioner by utilizing industrial solid wastes is characterized by comprising the following steps: the method comprises the following steps:

d. and c, uniformly mixing the composite strain obtained in the step c, the composite industrial solid waste and a curing agent according to the mass ratio of 0.1-0.5: 100: 5-20, and curing for 15-30 days to obtain the soil conditioner.

2. The method for preparing a soil conditioner using industrial solid waste according to claim 1, wherein: the sterile culture medium is an agar solid culture medium containing carbon, nitrogen, phosphorus and potassium.

3. The method for preparing a soil conditioner using industrial solid waste according to claim 1, wherein: the bacteria separation, domestication and culture processes adopt a plate streak inoculation method and a liquid culture medium inoculation method.

4. The method for preparing a soil conditioner using industrial solid waste according to claim 1, wherein: the red mud is Bayer process red mud, wherein the alkali content is 2-15%.

5. The method for preparing a soil conditioner using industrial solid waste according to claim 1, wherein: the coal gangue is solid waste discharged in the coal mining and coal dressing processes, and the sulfur content is 0.5-5%.

6. The method for preparing a soil conditioner using industrial solid waste according to claim 1, wherein: the curing agent is one or a mixture of a plurality of leaves, straws, pasture and weeds.

7. A method of using the soil amendment prepared by the method of claim 1, comprising: the soil conditioner is suitable for acid soil or saline-alkali soil, the application amount of the soil conditioner per mu is 100-200 kg, and the soil conditioner is used for planting corn and potato crops.