CN110467907B - Environment-friendly biomass dust suppressant and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of dust pollution treatment, and discloses an environment-friendly biomass dust suppressant and a preparation method thereof. The dust suppressant disclosed by the invention is low in cost, environment-friendly, non-toxic, harmless, easy to biodegrade, good in biocompatibility with plants and soil environments in a spraying area, and capable of being applied to dust control work together with green plants, so that comprehensive application of chemical dust suppression and plant dust retention is realized. When the dust suppressant solution is sprayed on the surface of dust, a continuous bonding layer with certain strength can be formed on the surface, the dust suppressant solution has better wind erosion and rain resistance, can bear the action of an extreme temperature environment for a longer time, and has certain moisture retention, thereby having better dust suppression and loss prevention effects.

Description

Environment-friendly biomass dust suppressant and preparation method thereof

Technical Field

The invention belongs to the technical field of dust pollution treatment, and particularly relates to an environment-friendly biomass dust suppressant and a preparation method thereof.

Background

Currently, the current state of the art commonly used in the industry is such that:

in recent years, with the accelerated development of industrial production and urban modernization processes in China, dust particles generated in human production and living processes such as industrial production, building construction, bulk material storage and transportation, motor vehicle exhaust emission and the like are increased year by year. Under the action of airflow power, a large number of dust particles are suspended in the air, so that haze weather with different severity degrees appears all over the country, serious influence is brought to the life and health of people, high social attention is caused, and how to take measures to economically and effectively prevent and treat air particle pollution becomes one of the hot problems of the research in the field of environmental protection. At present, the research and application of air dust particulate pollution prevention and control technologies at home and abroad are mainly started from aspects of controlling dust sources, cutting off the propagation path of dust particulate, inhibiting secondary dust emission and the like, and the aim of reducing the content of atmospheric dust particulate is achieved by adopting methods such as engineering measures, chemical inhibition, biological protection and the like. The chemical inhibition method comprises the steps of spraying a chemical dust inhibitor on the surface of an area easy to raise dust, capturing fine particles suspended in air by utilizing the physical and chemical action of solution substance components, inhibiting the raising of dust particles, enabling deposited dust to be solidified stably or directly generating a stabilizing effect on a loose surface capable of generating the raising dust, and reducing the raising dust, so that the aim of effectively eliminating or reducing the pollution of the dust to the environment is fulfilled.

In recent years, researchers pay more and more attention to economic cost benefits, application and implementation convenience and environment friendliness of raw material components of the dust suppressant while enhancing the effect of the solution on suppressing dust particles. The selection of the solvent components of the solution is started to gradually replace the traditional chemical components which are easy to cause secondary pollution by using a non-toxic, harmless and biodegradable biomass organic high molecular material, and attempts are made to extract substances from industrial, agricultural and domestic wastes, such as extracting wood fibers from waste liquor of a paper mill, extracting cellulose derivatives from crop straws and extracting alcohol compounds from waste residual oil, so that the waste is changed into valuable, and the effect of the dust suppressant on economically and effectively controlling and reducing the pollution of dust particles is fully exerted. The research on the application performance of the dust inhibitor mainly considers the multifunctional composite action of the solution and the performance of bearing the influence of external adverse environmental factors, and the dust inhibitor plays comprehensive roles of bonding, wetting, coagulation, moisture absorption, water retention and the like on dust particles by reasonably selecting the components of the raw materials, so that the consolidation strength and the moisture absorption and water retention performance of a bonded film are ensured, the dust inhibitor is fully adaptive to the influence of adverse factors such as wind, rain and the like in the practical application environment, the effective dust suppression period of the dust inhibitor is prolonged, and the purposes of stably consolidating and depositing dust and effectively avoiding secondary dust emission are achieved.

Compared with the material composition and application performance of the main ecological environment-friendly dust suppressant in recent years, the chemical dust suppressant prepared by singly applying the bio-organic high polymer material has poor wettability, is difficult to permeate, cannot form a surface bonding layer with enough thickness and strength, and has relatively poor application performance of bonding a single biomass material to form a film. Therefore, in order to fully exert the functions of reducing and controlling the pollution of dust particles by the dust suppressant, various non-toxic, harmless and biodegradable biomass materials need to be reasonably selected, and other components need to be properly added according to the action mechanism of the biomass materials. In order to enhance the permeability of the dust suppressant, researchers at home and abroad mainly add a chemically synthesized surfactant into a solution to reduce the interfacial tension, enhance the wettability of the solution to dust and realize the multifunctional composite action of the dust suppressant, but because the chemical surfactant has the defect of difficult biodegradation, although the main material of the solution is a biomass material, secondary pollution can still be caused and the ecological environment of soil in a spraying area is damaged. Therefore, the selection of the wetting agent component in the solution proportioning must also fully consider the environmental friendliness thereof, select non-toxic, harmless and biodegradable substances, and the selection of various biological organic high molecular materials should comprehensively consider the action mechanism, application performance, environmental effect and economic cost benefit of the component, and select an economic and reasonable component proportioning scheme.

In summary, the problems of the prior art are as follows:

(1) in the prior art, a chemical dust suppressant prepared by singly applying a biological organic high molecular material is poor in wettability and difficult to permeate, cannot form a surface bonding layer with enough thickness and strength, cannot fully adapt to the influence of adverse factors such as wind, rain and the like in an actual application environment, can prolong the effective dust suppression period of a dust suppressant, and cannot achieve the purposes of stably bonding and depositing dust and effectively avoiding secondary dust emission; and the application performance of a single biomass material bonded into a film is relatively poor.

(2) In the existing dust inhibitor, because the chemical surfactant has the defect of difficult biodegradation, although the solution main material is a biomass material, secondary pollution can still be caused, and the ecological environment of the soil in a spraying area is damaged.

The difficulty and significance for solving the technical problems are as follows:

in order to fully exert the functions of reducing and controlling the pollution of dust particles by the dust suppressant, various non-toxic, harmless and biodegradable biomass materials need to be reasonably selected, and other components are properly added according to the action mechanism of the biomass materials. In order to enhance the permeability of the dust suppressant, researchers at home and abroad mainly add a chemically synthesized surfactant into a solution to reduce the interfacial tension, enhance the wettability of the solution to dust and realize the multifunctional composite action of the dust suppressant, but because the chemical surfactant has the defect of difficult biodegradation, although the main material of the solution is a biomass material, secondary pollution can still be caused and the ecological environment of soil in a spraying area is damaged.

Therefore, the selection of the wetting agent component in the solution proportioning must also fully consider the environmental friendliness thereof, select non-toxic, harmless and biodegradable substances, and the selection of various biological organic high molecular materials should comprehensively consider the action mechanism, application performance, environmental effect and economic cost benefit of the component, and select an economic and reasonable component proportioning scheme.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an environment-friendly biomass dust suppressant and a preparation method thereof.

The environment-friendly biomass dust suppressant is prepared from 0.20-1.00% of carboxymethyl starch, 0.20-1.00% of carboxymethyl cellulose, 0.20-1.00% of sodium alginate, 1.00-5.00% of anhydrous calcium chloride, 0.05-0.25% of rhamnolipid, 0.05-0.25% of sophorolipid and 92.5-98.5% of water by weight percent.

When the dust suppressant solution is sprayed on the surface of dust, a continuous bonding layer with certain strength can be formed on the surface, the dust suppressant solution has good wind erosion and rain resistance, can bear the action of an extreme temperature environment for a long time, and has certain moisture retention, so that the dust suppressant solution has good dust suppression and loss prevention effects. Aims to prepare a novel environment-friendly biomass dust suppressant with application performance, ecological environmental protection and economic cost benefit by selecting nontoxic, harmless and biodegradable material and proportioning. The dust suppressant can meet the requirements of practical application environments, can realize effective dust reduction and control, has better biocompatibility with soil and ecological environments in spraying areas, can effectively solve the defects that the current ecological environment-friendly dust suppressant has poor application performance, wetting agent components are not easy to biodegrade and secondary pollution exists, can effectively reduce and control dust particulate pollution to provide novel dust suppressant solution, and provides a foundation for the comprehensive application of chemical dust suppression technology and plant dust retention.

Further, the preferable embodiment is 0.80% of carboxymethyl starch, 1.00% of carboxymethyl cellulose, 0.80% of sodium alginate, 1.00% of anhydrous calcium chloride, 0.20% of rhamnolipid, 0.05% of sophorolipid and 96.15% of water.

The invention also aims to provide a preparation method of the environment-friendly biomass dust suppressant, which comprises the following steps:

step one, adding deionized water into a reaction kettle according to mass percent, and heating to 50-70 ℃; adding carboxymethyl starch, heating the solution according to the strength grade of 0.5-1 ℃ rise per minute, and continuously stirring the solution at the stirring speed of 100-150 r/min until the carboxymethyl starch is completely dissolved and the solution is uniform.

Stopping heating, adding carboxymethyl cellulose after the temperature of the solution is reduced to 50-70 ℃, and uniformly stirring the mixed solution at the speed of 300-700 r/min; and adding sodium alginate, and uniformly stirring the mixed solution at the speed of 300-700 r/min.

And step three, preserving the heat of the mixed solution for 10-40 minutes according to the heat preservation temperature of 50-70 ℃ to obtain a uniformly mixed copolymer solution of three bonding film forming components.

And step four, adding anhydrous calcium chloride into the mixed solution under the heat preservation state of the step three, continuously stirring at the stirring speed of 100-150 r/min until the anhydrous calcium chloride is completely dissolved, and standing for 10-30 minutes.

And step five, heating the mixed solution obtained in the step four according to the intensity level of 0.5-1 ℃ rise per minute, simultaneously adding rhamnolipid, stirring at the speed of 300-700 r/min until the rhamnolipid is completely dissolved, and uniformly mixing.

And step six, continuously heating the solution according to the heating intensity in the step five, adding sophorolipid, and stirring at the speed of 300-700 r/min until the sophorolipid is completely dissolved, and uniformly mixing the solution.

And step seven, naturally cooling the mixed solution prepared at the high temperature to room temperature, stirring for 1 hour at the stirring speed of 100-150 r/min while cooling, stopping stirring and standing the solution for 1 hour, and finally obtaining a light yellow or yellow solution, namely the environment-friendly biomass dust suppressant.

In summary, the advantages and positive effects of the invention are:

the novel environment-friendly biomass dust suppressant is prepared by selecting nontoxic, harmless and biodegradable material materials and proportioning, and has application performance, ecological environmental protection and economic cost benefit. The dust suppressant can meet the requirements of practical application environments, can realize effective dust reduction and control, has better biocompatibility with soil and ecological environments in spraying areas, can effectively solve the defects that the current ecological environment-friendly dust suppressant has poor application performance, wetting agent components are not easy to biodegrade and secondary pollution exists, can effectively reduce and control dust particulate pollution to provide novel dust suppressant solution, and provides a foundation for the comprehensive application of chemical dust suppression technology and plant dust retention.

The dust suppressant disclosed by the invention is low in cost, environment-friendly, non-toxic, harmless, easy to biodegrade, good in biocompatibility with plants and soil environments in a spraying area, and capable of being applied to dust control work together with green plants, so that comprehensive application of chemical dust suppression and plant dust retention is realized.

When the dust suppressant solution is sprayed on the surface of dust, a continuous bonding layer with certain strength can be formed on the surface, the dust suppressant solution has good wind erosion and rain resistance, can bear the action of an extreme temperature environment for a long time, and has certain moisture retention, so that the dust suppressant solution has good dust suppression and loss prevention effects.

Compared with the prior art, the dust suppressant solution is easy to biodegrade, can be biologically compatible with plants and soil environment, and can be applied to dust particle control engineering together with plant dust retention measures. Through the performance test, the following conclusions are obtained:

(1) the dust suppressant disclosed by the invention has good bonding property, can effectively solidify dust particles and improve the surface strength, and a solidified layer keeps the basic shape unchanged under the actions of 8-grade strong wind weather, strong rain spray washing, dry-wet repeated environment and high-temperature heat at 50 ℃, can keep the water content above 4% for a long time, and has better engineering application performance;

(2) the pH value range of the dust suppressant belongs to subacidity or subacidity, the pH value of soil in a spraying area can be effectively adjusted, a soil environment suitable for plant growth is provided, the biodegradation rate in the soil microbial environment is obviously higher than that of the existing chemical dust suppressant, the survival of typical greening plant seedlings can be promoted to a certain degree, and the dust suppressant has good biocompatibility.

Drawings

FIG. 1 is a flow chart of a preparation method of an environment-friendly biomass dust suppressant provided by an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Aiming at the defects of the current dust particle treatment technology, the invention provides an environment-friendly biomass dust suppressant and a preparation method thereof, and the dust suppressant is low in cost, environment-friendly, non-toxic, harmless, easy to biodegrade, good in biocompatibility with plants in a spraying area and a soil environment, and capable of being applied to dust treatment work together with green plants to realize comprehensive application of chemical dust suppression and plant dust retention. When the dust suppressant solution is sprayed on the surface of dust, a continuous bonding layer with certain strength can be formed on the surface, the dust suppressant solution has good wind erosion and rain resistance, can bear the action of an extreme temperature environment for a long time, and has certain moisture retention, so that the dust suppressant solution has good dust suppression and loss prevention effects.

The environment-friendly biomass dust suppressant provided by the embodiment of the invention comprises, by weight, 0.20-1.00% of carboxymethyl starch, 0.20-1.00% of carboxymethyl cellulose, 0.20-1.00% of sodium alginate, 1.00-5.00% of anhydrous calcium chloride, 0.05-0.25% of rhamnolipid, 0.05-0.25% of sophorolipid and water. Water is added to make up to 100%.

The preferred scheme provided by the embodiment of the invention is that carboxymethyl starch is 0.80%, carboxymethyl cellulose is 1.00%, sodium alginate is 0.80%, anhydrous calcium chloride is 1.00%, rhamnolipid is 0.20%, sophorolipid is 0.05%, and the balance is water.

The following detailed description of the principles of the invention is provided in connection with the accompanying drawings.

As shown in fig. 1, the preparation method of the environment-friendly biomass dust suppressant provided by the embodiment of the invention comprises the following steps:

s101: adding deionized water into a reaction kettle according to the mass percentage, and heating to 50-70 ℃; adding carboxymethyl starch, heating the solution according to the strength grade of 0.5-1 ℃ rise per minute, and continuously stirring the solution at the stirring speed of 100-150 r/min until the carboxymethyl starch is completely dissolved and the solution is uniform.

S102: stopping heating, adding carboxymethyl cellulose after the temperature of the solution is reduced back to 50-70 ℃, and uniformly stirring the mixed solution at the speed of 300-700 r/min; and adding sodium alginate, and uniformly stirring the mixed solution at the speed of 300-700 r/min.

S103: and (3) preserving the heat of the mixed solution for 10-40 minutes according to the heat preservation temperature of 50-70 ℃ to obtain a uniformly mixed copolymer solution of the three bonding film forming components.

S104: and (5) under the heat preservation state of S103, adding anhydrous calcium chloride into the mixed solution, continuously stirring at the stirring speed of 100-150 r/min until the anhydrous calcium chloride is completely dissolved, and standing for 10-30 minutes.

S105: and (3) heating the mixed solution obtained in the step (S104) according to the intensity level of 0.5-1 ℃ rise per minute, adding rhamnolipid at the same time, stirring at the speed of 300-700 r/min until the rhamnolipid is completely dissolved, and uniformly mixing.

S106: and (4) continuously heating the solution according to the heating intensity in the step S105, adding the sophorolipid, and stirring at the speed of 300-700 r/min until the sophorolipid is completely dissolved, so that the solution is uniformly mixed.

S107: and naturally cooling the mixed solution prepared at the high temperature to room temperature, stirring for 1 hour at the stirring speed of 100-150 r/min while cooling, stopping stirring and standing the solution for 1 hour, and finally obtaining a light yellow or yellow solution, namely the environment-friendly biomass dust suppressant.

The application principle of the invention is further explained in detail by combining the main functions of each solvent component of the dust suppressant;

the composite material is a stable viscous colloid, has strong binding power and good toughness and thickening effect, can generate cross-linking reaction with cellulose derivatives and microbial polysaccharide gum to form a mixed copolymer, and provides a foundation for the binding and film forming of a dust inhibitor.

Carboxymethyl cellulose is anionic cellulose ether generated by carboxymethylation of cellulose, is easy to disperse in cold water or hot water to form a transparent colloidal solution with certain viscosity, can play roles in thickening, film forming, bonding, water retention, emulsification, suspension and the like, has good thermal stability, increases the viscosity along with the rise of temperature when the temperature is lower than 80 ℃, can perform a cross-linking reaction with a starch-based high molecular compound and a microbial polysaccharide gum to form a mixed copolymer, and provides a foundation for bonding and film forming of a dust inhibitor.

Sodium alginate is a natural polysaccharide extracted from brown algae, is a high-viscosity biopolymer compound, is easily dissolved in water to form uniform viscous liquid, and has good gelling property, thickening property and film forming property. The molecular chain of the sodium alginate contains a large amount of free carboxyl, has strong hydrophilicity, has strong protective colloid function, is easy to generate replacement reaction, can generate cross-linking reaction with a starch-based high molecular compound and a cellulose derivative to form a mixed copolymer, and provides a foundation for the adhesive film forming of the dust inhibitor.

The anhydrous calcium chloride is an inorganic salt formed by chloride ions and calcium ions, has strong moisture absorption, can absorb moisture in air to improve the water content of soil and enhance the moisture absorption and retention performance of a solution, and can play a role in lowering a freezing point and preventing frost expansion damage generated by application at a negative temperature in winter as an antifreezing agent.

The rhamnolipid is a glycolipid anion biosurfactant with biological metabolism property generated by pseudomonas or burkholderia, has water-oil amphipathy, can obviously reduce surface tension and enhance the permeability of a solution, has stress resistance to extreme environments such as acid, alkali, salt, heat and the like, is non-toxic and harmless, is easy to biodegrade, has no secondary pollution, and has antibacterial and antiviral properties.

The sophorolipid is lactone type glycolipid anion biosurfactant generated by candida secondary metabolism, has good emulsification, dispersion and solubilization characteristics, can obviously reduce surface tension and enhance the permeability of a solution, has small influence of extreme temperature, pH, salinity and other conditions on the surface activity, is non-toxic and harmless, has good compatibility with human bodies and environments, is easy to biodegrade, has no secondary pollution, and has the functions of resisting inflammation and resisting bacteria.

The application principle of the present invention will be further described in detail with reference to specific experiments;

before the environment-friendly biomass dust suppressant is put into practical use, experimental research is carried out on the wind erosion resistance, the repeated performance of rain resistance and dry-wet resistance, the permeability, the moisture absorption and retention performance, the temperature resistance and the frost resistance of the environment-friendly biomass dust suppressant. In order to make the objects, technical schemes and advantages of the invention more clear, the following describes the optimal proportioning dust suppressant in detail by combining the application performance test. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Experiment 1;

(1) test of weathering resistance

The dust is generated by suspending the deposited dust particles in the air under the action of wind. The wind erosion resistance experiment aims to investigate that a surface bonding layer formed after spraying the dust suppressant can be kept complete under the action of wind erosion, and the secondary raising of dust caused by the damage or the collapse of the bonding layer is avoided. In the experiment, 5 wind power grade standards such as 7.5m/s, 10m/s, 12.5m/s, 15m/s and 17.5m/s are respectively set from 4 grades capable of blowing dust and 8 grades of strong wind capable of breaking branches, wind speeds of different grades are simulated by a blower, a sand sample model sprayed with a dust inhibitor solution is continuously acted for 2 hours, the damage condition of a consolidation layer and the mass loss rate of sand are recorded, and the dust suppression efficiency of the dust suppressant is researched.

(2) Repeated performance test of rain resistance and dry and wet resistance

The repeated performance test of rain resistance and dry-wet resistance aims to investigate whether a surface bonding layer formed after spraying a dust inhibitor can be kept intact under the rain wash when rain and fine weather occur alternately, whether bubbles can be generated or expansion crack, collapse and looseness can occur under the rain wash, whether the strength of the bonding layer is changed after moisture evaporation, and whether the sand quality can cause loss. The determination of the rainwater spraying amount in the experiment is based on the one-hour rainfall rating division standard, four grades of light rain (2L/m2), medium rain (6L/m2), heavy rain (12L/m2), heavy rain (16L/m2) and the like are respectively set, a one-hour simulated rainwater washing experiment is carried out on a cake-shaped sandy soil sample solidified and formed on the inner surface of an evaporating dish, and the change condition of a cake-shaped model surface solidification layer under rainwater washing in the spraying process is observed and recorded in real time. After a rainwater spraying experiment, the evaporating dish is placed in a programmable high-temperature experimental box, the temperature is set to be 40 ℃, the evaporating dish is taken out after 8 hours, and the hardness change of the dried surface bonding layer is qualitatively judged. Repeating the steps for a plurality of times until the surface of the model bonding layer is cracked.

(3) Permeability test

The penetration performance of the dust suppressant determines the depth of a soil sample which penetrates downwards after the dust suppressant is sprayed to an area easy to raise dust, namely the thickness of a finally formed surface bonding layer. On the basis of meeting a certain consolidation strength, the dust suppressant solution must have enough permeability to form a surface consolidation layer with effective thickness in practical application, so that the bonded dust particles are prevented from being cracked and loosened under the action of an external environment to generate secondary dust pollution. In the experimental process, sand samples collected on site are filled into glass tubes with the same height and diameter and one closed end, vibration tamping is carried out to be flat, the same tamping degree of the sand samples in each group of glass tubes is guaranteed, the sand samples are all 20cm in height, the sand samples are fixed on a vertical flat plate marked with scales, a burette is used for sucking equivalent (2ml) dust inhibitors, the dust inhibitors are slowly dripped into the glass tubes at a constant speed, and the penetration depth of the dust inhibitors in the sand samples is recorded when the solution is just dripped, 30s, 1min30s, 2min, 3min, 4min and 5min after the solution is dripped and when the penetration is basically stopped.

(4) Moisture absorption and retention

According to the research result of the dust raising mechanism, if the consolidated moisture content of the dust can be kept above 4%, the generation of the dust can be effectively inhibited. In the experiment, a sandy soil sample is spread in a glass dish, after a dust inhibitor is uniformly sprayed on the surface of the sandy soil sample, the sandy soil sample is weighed by an analytical balance, placed in a constant-temperature and constant-humidity environment with the temperature of 25 ℃ and the humidity of 60 percent, reweighed every 12 hours, the mass change of the sandy soil sample is recorded, and the change of the water content of the sandy soil sample along with time is observed and recorded until the change is stable.

(5) Temperature and freezing resistance test

The temperature resistance and frost resistance tests aim to investigate whether a surface bonding layer formed on a spraying surface by the dust inhibitor can adapt to an extremely high-temperature or low-temperature environment. Wherein, the temperature resistance experiment is carried out in a programmable high-temperature experiment box, the experiment temperature is set as 50 ℃ of the summer pavement limit temperature of the long sand area, a sand soil sample model which is uniformly sprayed with the dust inhibitor and is subjected to surface consolidation forming is put into the programmable high-temperature experiment box, the change of a surface consolidation layer is observed and recorded at intervals of 12 hours, and the surface peeling, peeling and thermal cracking time is used as the high-temperature resistance index of the dust inhibitor; the anti-freezing performance test is carried out in a refrigerator, the test temperature is set to be-5 ℃ of the pavement limit low temperature in winter in a long sand area, a sand soil sample model which is uniformly sprayed with the dust inhibitor and is formed on the surface is put into the refrigerator, the change of a surface solidification layer is observed and recorded at intervals of 12 hours, and the time of freezing and swelling on the surface is used as the anti-freezing performance index of the dust inhibitor.

(6) Experiment of biodegradability

Biodegradation performance experiments the ease of biodegradation of solutions was characterized by the decrease in mass of dust suppressant sprayed under the action of the soil microbial environment. In the experiment, the environment-friendly biomass dust suppressant is poured into a watch glass, placed in a ventilated and dry environment, after a film with a certain thickness is formed on the naturally air-dried surface of the watch glass, the initial film weight is weighed, a layer of nylon window gauze is respectively arranged on the upper surface and the lower surface of the watch glass, the watch glass is buried in a flowerpot with a surface covered with a fresh soil sample sampled in an actual dust raising area with the depth of 8-10cm, the flowerpot is placed in an open-air natural environment to be subjected to biodegradation, the watch glass is taken out periodically every week, the watch glass is weighed after surface soil is removed, and the change condition and the mass loss rate of the surface fixing film in different burying times are recorded.

(7) Testing of biocompatibility

The biocompatibility performance test was aimed at investigating whether the dust suppressant solution would have an effect on the normal growth and development of plants. In the experiment, seedlings of four plants, namely tea trees, sweet osmanthus flowers, red junior trees, schefflera arboricola and the like with similar budding rates and to be budded, are taken as research objects, are respectively and uniformly sprayed with biomass dust suppressant solutions with the same amount and different solid contents, the seedlings are placed under the same environmental conditions for cultivation, after the solutions completely permeate and a consolidation layer is formed on the soil surface of an experimental group sprayed with a dust suppressant, quantitative water is sprayed every 2 days, the growth conditions of the plant seedlings of each group are contrastingly observed, and the biocompatibility of the biomass dust suppressant is represented by the survival rate of the plant seedlings after 30 days.

Experimental phenomena and results;

(1) resistance to weathering

Under the action of blowing of a blower, the soil sample sprayed with the dust suppressant has no obvious change, the surface bonding layer is basically kept intact, and local cracks appear only under 8-level strong wind. The surface variation of the consolidated layer and the wind erosion mass loss rate of the model for 5 different wind force classes are shown in table 1.

TABLE 1 test results of weathering resistance

The experimental results shown in table 1 show that the environment-friendly biomass dust suppressant has dust suppression efficiency of over 95% under the action of 4-grade wind and 8-grade strong wind, has good wind erosion resistance, can keep stable consolidation under the action of external wind, and can effectively avoid secondary dust emission.

(2) Repeated resistance to rain and dry and wet

The change of the appearance characteristics of the surface bonding layer formed by the dust suppressant in the spraying area under the simulated rainwater spraying effect of different grades, the change of the bonding strength after evaporation and water loss and the repeated times of the model which can bear dryness and wetness are shown in table 2.

TABLE 2 repeated performance test results of rain resistance and dry and wet resistance

The results in table 2 show that the surface bonding layer of the environment-friendly dust suppressant can be kept bonded under the rain water spray scouring action of three grades such as light rain, medium rain and heavy rain, the bonding strength is still good after evaporation and water loss, the environment-friendly dust suppressant is not easy to damage, and can bear the repeated dry-wet circulation action for more than 5 times. When the simulated spraying amount grade is rainstorm, the surface of the surface consolidation layer is soft under the action of rain wash, bubbles exist, the consolidation strength is obviously reduced after evaporation and water loss, the surface is easy to damage, and the consolidation layer is cracked after 3 times of dry-wet repeated circulation action. In view of relatively low occurrence frequency of rainstorm, experimental results prove that the environment-friendly dust suppressant has relatively good repeated performances of rain resistance and dryness and wetness, and can adapt to repeated actions of rain and fine weather in the real environment.

(3) Permeability performance

The environment-friendly dust suppressant starts to permeate downwards when contacting with a sandy soil sample, the permeation speed is gradually reduced along with time, the infiltration depth of 25 biomass dust suppressant solutions with different concentration ratios in 60s in the sandy soil sample reaches more than 1cm, the permeation tends to be gentle after 300s, the permeation capability tends to zero after 2h, the permeation is basically stopped, and the final permeation depth is 6.05 cm. The solution penetration depth at different time points is shown in table 3.

TABLE 3 penetration Performance test results

(4) Moisture absorption and retention

And comparing the soil sample sprayed with the dust suppressant and the soil sample sprayed with water, wherein after evaporation drying, the soil sample using the dust suppressant has a complete and compact surface, the dust still remains effectively consolidated, and the soil layer on the surface of the soil sample of the control group is relatively loose, so that secondary dust raising is easy to occur. The change in the consolidated moisture content of the experimental sand samples is shown in table 4.

TABLE 4 moisture absorption and retention Properties test results

As can be seen from the results in Table 4, the water content of the soil sample sprayed with water is reduced to 4% after 36h, and the effective moisture retention time of the soil sample sprayed with the environment-friendly biomass dust suppressant can reach 108 h. Experimental results prove that the environment-friendly biomass dust suppressant has good moisture absorption and retention performance, a bonding layer can be kept wet for a long time, and secondary dust emission is effectively avoided.

(5) Temperature and frost resistance

Within the experimental observation time (120h), the sand soil sample surface bonding layer sprayed with the environment-friendly biomass dust suppressant is completely covered, no thermal peeling or shedding occurs under the action of high-temperature heat, and no frozen swelling occurs under the action of low-temperature environment.

(6) Biodegradability

In the experimental period (35d), the quality of the film formed by the environment-friendly biomass dust suppressant on the watch glass under the action of the soil microorganism environment changes, i.e. the biodegradation rate is shown in table 5.

TABLE 5 results of biodegradation Properties

As can be seen from the results in Table 5, the biodegradation rate of the dust suppressant of the invention in 35 days can reach 64%, which is far higher than that of the existing dust suppressant. Experimental results prove that the environment-friendly biomass dust suppressant has good biodegradability and does not cause secondary pollution to the soil environment of a spraying area.

(7) Biocompatibility Properties

The survival rates of young plants of four experimental samples sprayed with the environment-friendly biomass dust suppressant and water according to the present invention are shown in Table 6.

TABLE 6 results of biocompatibility Performance experiments

As can be seen from the results in Table 6, the spraying of the dust suppressant of the present invention significantly improved the survival rate of seedlings and promoted the growth of plants, as compared to the control group sprayed with water alone. Experimental results prove that the environment-friendly biomass dust suppressant has good biocompatibility and can be applied to dust treatment work together with plant dust retention.

By combining the application performance test results, the environment-friendly biomass dust suppressant has good comprehensive application performance, can form a surface bonding layer with a certain thickness in a spraying area in a penetrating manner, can bear the wind erosion action of 8-grade strong wind, can keep the bonding moisture content above 4% for a long time under the repeated action of rain spray scouring and the drying and wetting of rainwater and fine weather, can keep the bonding moisture content intact within the range of-5 to 50 ℃, has good cold and heat stability, has nontoxic and harmless components and is easy to biodegrade, has good biocompatibility with common shrub species such as tea trees, sweet osmanthus flowers, redcurrants, schefflera arboricola and the like, and can be jointly applied to dust particulate treatment engineering with plant dust.

The dust suppressant material disclosed by the invention has the selection principle of environmental friendliness, dust suppression and loss prevention effects and economy, and firstly all solvent components are required to be eco-friendly and can be biocompatible with plants and soil environments in a spraying area, secondly the solvent components are required to play a good suppression role on dust, and the application performance index parameters such as consolidation strength, permeability, moisture absorption and retention property, temperature resistance and frost resistance are good; and the solvent component is required to be wide in source, low in cost, simple to prepare, convenient to use and feasible to popularize.

Compared with the prior art, the dust suppressant solution is easy to biodegrade, can be biologically compatible with plants and soil environment, and can be applied to dust particle control engineering together with plant dust retention measures. Through the performance testing test, the following conclusions are reached: the dust suppressant disclosed by the invention has good bonding property, can effectively solidify dust particles, improves the surface strength, keeps the basic shape of a solidified layer unchanged under the actions of 8-grade strong wind weather, strong rain spray washing, dry-wet repeated environment and high-temperature heat at 50 ℃, can keep the water content above 4% for a long time, and has better engineering application performance.

The pH value range of the dust suppressant belongs to subacidity or subacidity, the soil pH value of a spraying area can be effectively adjusted, a soil environment suitable for plant growth is provided, the biodegradation rate in the soil microbial environment is obviously higher than that of the existing chemical dust suppressant, the survival of typical greening plant seedlings can be promoted to a certain degree, and the dust suppressant has good biocompatibility.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (1)

1. The environment-friendly biomass dust suppressant is characterized by consisting of 0.80 percent of carboxymethyl starch, 1.00 percent of carboxymethyl cellulose, 0.80 percent of sodium alginate, 1.00 percent of anhydrous calcium chloride, 0.20 percent of rhamnolipid, 0.05 percent of sophorolipid and 96.15 percent of deionized water in percentage by weight;

the preparation method of the environment-friendly biomass dust suppressant comprises the following steps:

step one, adding deionized water into a reaction kettle according to mass percent, and heating to 50-70 ℃; adding carboxymethyl starch, heating the solution according to the strength grade of 0.5-1 ℃ rise per minute, and continuously stirring the solution at the stirring speed of 100-150 r/min until the carboxymethyl starch is completely dissolved and the solution is uniform;

stopping heating, adding carboxymethyl cellulose after the temperature of the solution is reduced to 50-70 ℃, and uniformly stirring the mixed solution at the speed of 300-700 r/min; adding sodium alginate, and uniformly stirring the mixed solution at the speed of 300-700 r/min;

step three, preserving the temperature of the mixed solution for 10-40 minutes according to the heat preservation temperature of 50-70 ℃ to obtain a uniformly mixed copolymer solution of three bonding film forming components;

step four, adding anhydrous calcium chloride into the mixed solution under the heat preservation state of the step three, continuously stirring at a stirring speed of 100-150 r/min until the anhydrous calcium chloride is completely dissolved, and standing for 10-30 minutes;

step five, heating the mixed solution obtained in the step four according to the intensity level of 0.5-1 ℃ rise per minute, simultaneously adding rhamnolipid, stirring at the speed of 300-700 r/min until the rhamnolipid is completely dissolved, and uniformly mixing;

step six, continuously keeping heating the solution according to the heating intensity in the step five, adding sophorolipid, and stirring at the speed of 300-700 r/min until the sophorolipid is completely dissolved, and uniformly mixing the solution;

and step seven, naturally cooling the mixed solution prepared at the high temperature to room temperature, stirring for 1 hour at the stirring speed of 100-150 r/min while cooling, stopping stirring and standing the solution for 1 hour, and finally obtaining a light yellow or yellow solution, namely the environment-friendly biomass dust suppressant.

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