Research Progress of Bio-organic Dust Suppressants

Both natural and human-generated dust can cause serious harm to the environment and human health. Since the dust suppressants can accelerate the dust settlement more effectively to prevent the dust from raising; at the same time, to comply with the concept of environmental protection, the use of natural bioorganic materials to prepare dust suppressants has become a research hotspot. This paper summarizes the working principle of dust suppressants and the evaluation indexes of the performance of the dust suppressants, reviews the methods and research results of using bio-organic materials such as polysaccharides, lignin, proteins, microorganisms, agricultural and forestry wastes to prepare dust suppressants in recent years, and puts forward the suggestions on the problems of the current bio-organic dust suppressants to provide a reference for their further development in the future.


Introduction
Dust is defined as solid particles suspended in the air.Naturally occurring wind and sand, as well as human activities such as road dust, coal mining operations, and construction sites, are main sources of dust.As the concentration of particulate matter in the air increases, it adversely affects respiratory, cardiovascular, immune, and mental health [1].The most serious is the coal dust generated in the workplaces of coal mining areas, which not only leads to mine explosions when it reaches a specific concentration but also makes miners beings suffer from pneumoconiosis, seriously threatening the safe and efficient production and health of miners.In addition, the new coronavirus can attach to dust to form airborne aerosols that can be easily inhaled by the human body and cause infection.Therefore, effective measures must be taken to control air pollution, especially dust pollution, in order to reduce the amount of dust in the air, improve air quality, and protect people's physical and mental health.
Traditional dust prevention and control measures mainly consist of covering dust prevention and sprinkling dust suppression [2].The dust reduction technology in the coal mine area includes the methods of water injection into the coal beds, ventilation dust reduction, spraying dust reduction, dust collector dust reduction, and other methods.In the 1930s, due to chemical dust suppressants methods is more effective than traditional dust suppression methods, foreign scholars began to conduct a large number of studies.Since then, this method has been widely adopted and continuously developed in all countries.Although China began to develop the chemical dust suppressants in the late twentieth century, it has made great progress in chemical dust suppressants [3][4].
The three categories of traditional dust suppressants are wetting dust suppressants, bonded dust suppressants, and cohesive dust suppressants [5].Wetting dust suppressants are formulated from hygroscopic inorganic salts and some surfactants.It is based on the principle of similar solubility and achieves the effects of emulsification, foaming, wetting, and penetration by reducing the surface tension of the solution.However, in practical application, it is found that the dust suppression period is short, and it is easy to cause secondary dust [6].Bonded dust suppressants are divided into bonded organic chemical dust suppressants and inorganic chemical dust suppressants.This dust suppressant uses the principles of bonding and curing to form a curing layer on the dust-suppressing surface to achieve the effect of dust fixation.However, some bonded dust suppressants are relatively poor in performance, difficult to degrade or have the issue of secondary pollution [7].Cohesive dust suppressants through the absorption of water molecules so that the dust particles maintain a high-water content, thus accelerating the dust settlement to accomplish the dust suppression effect.It is divided into two categories: high-absorbent resin dust suppressant and moisture-absorbent inorganic salts dust suppressant.High-absorbent resin dust suppressant has good water retention performance is good, strong bonding, high water absorption.But it is difficult to prepare and costly.The aqueous solution of hygroscopic inorganic salt dust suppressant is highly corrosive, and there is the problem of corrosion of equipment or alteration of the properties of certain materials [8].Due to the practical implementation of the traditional dust suppressant's single performance, a composite chemical dust suppressant with wetting, bonding, and cohesion has been developed by combining a variety of chemicals.Similarly, functional dust suppressants have been developed to a certain extent.Some dust suppressants for coal dust particles can play a role in flame retardant, some dust suppressants contain anti-freezing properties, some have acid and alkali resistance, and some dust suppressants to avoid the corrosion effect on metal [9].With the development of chemical dust suppressants, they have issues with ineffective dust suppression and substantial pollution.So, researchers began developing new environmentally friendly dust suppressants with the objectives of being green, biodegradable, inexpensive, and effective.Due to their eco-friendly properties, such as the renewability of raw materials and biodegradability, bioorganic materials have been widely used in preparing environmentally friendly dust suppressants in recent years.Modified waste and natural materials (e.g., polysaccharides, proteins, microorganisms, etc.) show potential as components of dust suppressants [10].

Dust suppression principle
Dust suppressants accomplish their goal of reducing dust by catching, adsorbing, and aggregating dust particles, then firmly binding them in a mesh structure.Accordingly, dust suppressants have wetting, coalescing, anti-erosion, and anti-washout effects on dusts.The current dust suppression mechanism has three kinds of wetting, coagulation, and consolidation [11]: The wetting mechanism is to wrap the dust particles by spraying the dust suppressant to absorb the surrounding moisture and keep them wet.At the same time, it increases the dust particles' density, thus speeding up the dust fall rate.The primary raw materials are chemicals with hygroscopic effects, surfactants, and other materials [12].
The cohesion mechanism uses the dust suppressant to bond the fine dust particles together or increase the bonding strength between the dust particles to make them agglomerate into large dust particles, thus accelerating the settling of dust while preventing the dust from rising to achieve the purpose of dust suppression.The primary raw materials are hygroscopic inorganic salts and other materials.
The solidification mechanism uses the coagulation film-forming properties of chemicals to form a solidified layer on the dust surface and to solidify the dust particles on the dust suppression surface so that it is not easy to diffuse and generate pollution.The primary raw materials are hydrophilic or polymers with good film-forming properties, such as starch, cellulose, bio-gum, and other polysaccharides.
A schematic diagram of the three dust suppression principles is shown in Figure 1.

Sugar-based dust suppressant 3.1.1. Natural polysaccharides dust suppressant
Natural polysaccharides have good renewability, degradability, and film-forming properties.It can create three dimensional networks structures by covalent or noncovalent bond.So, polysaccharides have been widely used in preparing environmental protection dust suppressants [13].According to the different characteristics of polysaccharides, structural modification is carried out through physical or chemical modification means so that they can improve the relevant dust suppression ability, thus preparing degradable polysaccharide-based dust suppressants with excellent performance.The commonly used raw materials are starch-based, cellulose-based, polysaccharide biopolymers.Table 1 shows the methods and effects of different sugar bases for the preparation of dust suppressants.
Starch-based dust suppressant has good hydrophilicity and adhesion; by filling the gaps between the dust particles, the dust particles are tightly agglomerated and cemented on the dust suppression surface.At the same time, it can wet the dust to reduce the surface tension and thus inhibit the evaporation of water molecules to achieve the effect of dust suppression.Natural starch has disadvantages such as poor solubility and poor fluidity, which affects its application.Due to the modified starch has good moisture absorption, fluidity, permeability, adhesion, and simple production process, it is widely used in the preparation of dust suppressants.
For example, Bao et al. [14] used acrylic acid-modified starch to form starch graft copolymers to prepare dust suppressants [15].The modified product has a high viscosity and low cost.In order to capture dynamic dust and inhibit static dust more effectively, Xu et al. [16] used the Cu 2+ /H2O2 System to oxidize tapioca starch to produce a material with high consolidation and low viscosity.This product can reduce the limitations of binder addition on foam foaming ability and wetting performance, and achieve the curing of dust.At the same time, it has a good wetting effect on long-flame coal, and the dust suppression rate of PM10 is 98.17%.
The nonionic groups in cellulose are easy to adsorb with the reactive groups of other particles to form hydrogen bonds, thus bonding with the particles.This property can be used as a binder component in the dust suppressant, which makes the cellulose molecules coalesce with the coal dust to accelerate the dust settling and achieve the effect of dust suppression [17].In order to improve the performance of cellulose-based dust suppressants, more cellulose derivatives or modified cellulose are used as raw materials for dust suppressants.Ma et al. [18] based on copolymerization of free radicals, used acrylamide and acrylic acid as the graftmonomers to conduct chemical modification on hydroxyethyl cellulose to prepare a type of agglomeration-cementing dust suppressant.The hydroxyethyl-modified cellulose improved the mobility and adhesion and could better bind with coal dust particles to enhance the suppression effect.In addition, Nanoscale cellulose is also being used in the development of dust suppressants.Nano cellulose has high water absorption in addition to the inherent properties of cellulose.Bian et al. [19] prepared a polymer dust suppressant by using nanocellulose as the main raw material, grafting acrylic monomer to the main structure by graft copolymerization, and adding an appropriate amount of sodium dodecylbenzene sulfonate.SEM observed that the product could be effective in solidifying the coal dust particles.Experiment results showed that the dust suppression efficiency of up to 98%, it has a good coagulation and moisturizing effect, and long dust suppression period.However, the research on nano cellulose in dust suppressants is relatively small; the next step can be the nano cellulose microscopic level of dust suppression mechanism research.
Despite its viscosity, sodium alginate is only marginally soluble in water, which limits its adhesion to dust.Consequently, sodium alginate's solubility needs to be improved.Yan et al. [20] used sodium alginate and xanthan gum as monomers, a modified experiment was conducted by cross-linking the two monomers with epichlorohydrin crosslinking agent.They fabricated a soluble gel dust-suppressant with strong waterretention properties by modifying the -OH in sodium alginate and inserting hydrophilic groups.

Polysaccharide biopolymers dust suppressant
Polysaccharide biopolymers are widely used as thickeners in food and other industries and are often used as soil stabilizers in the environmental field.Currently, chitosan, guar gum, and xanthan gum are widely used in the preparation of dust suppressants.To dust suppression, polysaccharide biopolymers often need to be modified according to specific application conditions for practical usage.Meanwhile, they can either be used alone as a component of a dust suppressant or can be used to modify other raw materials to improve their dust suppressant properties.
Chitosan exists in a large number of shrimps and crabs, and other marine arthropods in the shell.It is a linear polymer with a double helix structure.As chitosan comprises numerous amino, hydroxyl, and coordination groups, it exhibits great reactivity, good water retention, and water-holding properties.However, the water solubility of chitosan is poor, and it can be further modified to achieve better dust suppression.Liu et al. [21] prepared a solidifying dust suppressant based on modified chitosan by quaternization synthesize.The modified product improves the water solubility and viscosity of the raw material and enhances the curing performance and wind erosion resistance.It has an excellent miscible curing effect on coal dust, and can be applied to different operating sites in coal mining areas.At present, the extraction methods of chitosan in China are primarily chemical and biological methods.The chemical method will produce a large number of high concentrations of acid and alkali waste liquid.The biological methods are time-consuming and have low extraction rates.In order to solve this problem, Zhou et al. [22] improved the extraction method.They used waste shrimp shells to extract chitosan as a raw material, to carry out graft polymerization with acrylic acid and polyvinyl alcohol-1788, and to carry out amidation crosslinking reactions with ethylenediamine tetraacetic acid to prepare a dust suppressant.The product can maintain over 90% dust suppression rate even under high wind speed and has good cyclic dust suppression.Moreover, Zhou et al. [23]applied to oil and microcapsule technology for dust suppression.The oil-based dust suppression microcapsules use rapeseed oil as the core material of the microcapsules, chitosan quaternary ammonium salt (HACC), chitosan derivatives, and sodium alginate (SA) biopolymers as the shell material.The experiments showed that the microcapsule effectively combines with coal dust and exhibits strong wind erosion resistance.Experiment results showed that, at the optimal concentration, microcapsules exhibit a dust suppression rate of approximately 92% for coal dust when wind speeds reach 12 m/s.The decomposition period ranges from 14 to 28 days, aligning with environmental protection ideals.
The unique internal structure of guar gum allows it to bind and hold water better than other materials.However, it dissolves slowly in water and produces a viscosity that is difficult to control.To improve these problems, Zhang et al. [24]modified the hydrophilic groups in guar gum using a modifying reagent synthesized from sodium amino sulfonate to enhance its water retention capacity and control its viscosity.They then compounded the modified product with glycerol and sodium dodecyl benzene sulphonate and fatty alcohol polyoxyethylene ether to produce a dust suppressant.The experiments showed that the coal dust samples treated with the product had an aggregation and coagulation effect, which could effectively inhibit the diffusion of coal dust, and had a certain degree of natural degradation without causing secondary pollution.However, the long-term nature of guar gum dust suppression requires further investigation.
The rheological properties, physical and chemical properties, and biodegradability of xanthan gum are better than that of other similar materials.Xanthan gum can replace the traditional soil stabilizer, because of these properties, it can be used as a binder.Secondly, modified xanthan gum is an excellent polymeric water-absorbing material.Wei et al. [25] prepared an environmentally friendly interpenetrating double network hydrogel dust suppressant using polyvinyl alcohol, xanthan gum and acrylic acid, which improved the poor mechanical properties of existing hydrogel dust suppressants.Experiment results showed that the product can effectively inhibit the generation and spread of coal dust; it is suitable for dust control during coal mining, transportation, and storage, and is non-toxic, harmless, and degradable.In addition, xanthan gum can also be modified by glycosylation to improve the physicochemical properties of the material to achieve a better dust suppression effect [26].
Guar gum and xanthan gum demonstrated outstanding performance in bonding, thickening, and viscosity enhancing.Meanwhile, due to the effectiveness of gum such as guar gum and xanthan gum in the preparation of dust suppressants, Ke et al. [27] used the mixed product of guar gum and xanthan gum as substrate to produce a synergistic thickening effect and prepared a dust suppressor by grafting copolymerization.The dust suppressant increases the wettability and water retention of coal dust, and can effectively target limestone mine dust.In addition, according to coal dust's features of small particle size, low viscosity, and low moisture content, Nie et al. [28] developed a composite dust suppressor with natural locust bean gum as a binder, combined with other substances.The dust suppressant increases the wettability and water retention of coal dust.The product demonstrates noteworthy adsorption and binding capabilities to low-grade coal, and a dust reduction rate of 92.3% has been achieved.Wang et al. [29]improved the wetting and dust suppression properties of pectin by graft copolymerization.They investigated the effects of different methoxy levels of pectin on the wetting and agglomeration of coal.The results showed that the low-methoxy pectin-modified dust suppressant could effectively wet coal dust, and is non-toxic and degradable.
Table1.Methods and effects of different sugar bases for the preparation of dust suppressants.

Polyphenolic groups dust suppressant
Lignin has become an attractive substitute for adhesives due to its phenolic nature [30].In addition, lignin has varied functional groups, and a variety of chemical reactions can improve its range of applications.The sulfonation reaction of lignin is usually used to produce dust suppressants in the form of lignin sulfonate, which has good water solubility.Hydroxyl and sulphonic acid groups in the internal molecular structure of lignosulphonates can combine with dust particles to form a hardening layer on the surface of the dust to achieve the effect of dust suppression.Li et al. [31] performed a graft copolymerization reaction using sodium lignosulfonate and acrylic acid.To enhance bonding and water retention, they added calcium chloride, sodium tetraborate, and sodium methyl silicate to the modified product.This dust suppressant fulfills the requirements for coal transport and storage.The difference is that Li et al. [32] extracted lignin from waste liquid produced during papermaking, followed by sulfonation treatment.They then prepared mining dust suppressants by adding a certain amount of surfactant to the modified product.This product has the properties of a surfactant and improved wetting ability of coal dust.
Other studies have found that the frequent use of lignosulfonates can have a corrosive effect on metals and even harm aquatic organisms [14].So, the next step of the study can be compounded with some corrosion inhibitors to reduce the corrosive effect on metals and avoid the use of in the environment where aquatic organisms survive.

Natural products
Based on the current concept of "treating waste with waste," cellulose, lignin, chitosan, and other components (such as bagasse, straw, shrimp shells, etc.) extracted from plants and agricultural and forestry wastes are used to prepare dust suppressants to achieve resource utilization.
To solve the low efficiency and economy of cellulose matrix extraction, Zhou et al. [33] used bagasse extracted cellulose from sugar production waste as a matrix and adds polyvinyl alcohol and polyacrylamide as monomers to prepare a wetting-crusting type highly efficient environmental protection dust suppressant.The experimental results showed that the product had high strength and good permeability of the solidified layer.It can meet the requirements of dust suppression in the process of coal mining and transportation.
Zhang et al. [34] produced a puffing solution by steaming saline seedcake at high temperatures.They then crosslinked the solution with a water-soluble polymer to prepare an eco-friendly dust suppressant.The product exhibits strong adhesion, moisture retention, and water stability.Furthermore, the dust suppressant has the impact of enhancing crop growth after application and can efficiently manage soil dust.
The aqueous solution of enteromorpha polysaccharides is gelatinous and has good application potential as a functional thickener, emulsifier and stabilizer.Meanwhile, the polysaccharide structure of enteromorpha contains a large number of hydroxyl groups that can be used as a basis for graft copolymerization.Zhao et al. [35] prepared an enteromorpha-based environmentally friendly dust suppressant by graft polymerization.The product can enhance the moisture capacity of coal dust and effectively suppressing dust without causing secondary pollution.Additionally, it exhibits excellent stability.This product offers a novel solution to the challenge of managing seaside enteromorpha effectively.Wang et al. [36] prepared a dust suppressant using a graft copolymerization of polyacrylamide and enteromorpha, and the dust suppression efficiency can reach 89-94%.In addition, enteromorpha can save 30% of the material cost.
Liang et al. [37] used cellulase enzyme to digest corn stover to obtain an enzymatic solution.Adding environmentally friendly additives to this enzymatic solution to prepare dust suppressants.This product has good wettability and evaporation resistance, and can effectively suppress dust.The reuse of corn stoves can help to reduce waste and environmental pollution and realize the increase of the added value of renewable resources.
Feng et al. [38] used peanut shell extract nanocellulose as the main raw material to prepare a dust suppressant by aqueous solution polymerization method.Performance testing of the product through simulated open-air transport experiments.The experiments showed that this dust suppressant has good wind erosion resistance, evaporation resistance, and stability.It can inhibit coal dust effectively.
The process of using agroforestry biomass waste to prepare dust suppressant needs to fully consider its nature, treatment methods, and additives selection to ensure the performance and stability of the product.
Table 2 for dust suppression.In early studies, some researchers extracted proteins from molasses as components of dust suppressants [13].However, the cost of protein-based materials is high, and the number of applications is small.In recent years, modified soya isolate protein has been widely used as a raw material for the manufacture of dust suppressants.Soybean isolate protein contains many active functional groups; in addition to excellent biological properties, water absorption, water retention, gelling, foaming and other functional properties can also reduce the surface tension of water and oil.Therefore, the dust suppressant can improve the permeability between dust particles and increase the wetting degree to make the dust settle quickly.In addition, the active functional group can be modified by chemical methods or compounded with other agents to improve viscosity, water retention and wetting effect, thus improving the dust suppression ability.Jin et al. [39] prepared a dust suppressant using an anionic surfactant, sodium dodecyl sulfate, modified soybean isolate protein, adding sodium carboxymethyl cellulose and sodium methane silicate.The hydrophobic functional groups in the modified protein-surfactant product moved outwards, resulting in better absorption of the hydrophobic functional groups and thorough cementation of the coal dust, leading to dust suppression.Compared to that of the unmodified solution, the viscosity and water retention of the modified product were further improved, thus enhancing the cementing ability of coal dust particles, and meeting the requirements for use in coal mines.Traditional polymer dust suppressants are limited due to environmental pollution, and polymer gels have been applied due to the advantages of environmental protection and good biocompatibility.Since sugar components such as xanthan gum can stabilize protein conformation and improve protein gelation, Dong et al. [24] prepared a dust suppressant with a gel network structure from soybean isolate protein by xanthan gum glycosylation.The modified product had improved flowability, water retention and thermal stability.The dust suppression efficiency of PM2.5 and PM10 can reach 98.09 % and 98.10 % respectively.

Microbial-based dust suppressant
Microbial-based dust suppressants usually use microorganism-induced calcium carbonate precipitation to coalesce dispersed dust particles into large particles, thus acting as a dust suppressant.This process can be achieved by urea hydrolysis, nitrate reduction, sulfate reduction, iron reduction, etc., which is an economical and environmentally friendly technology [40].Among them, the urea hydrolysis reaction process is the most widely used because it is easy to control and can produce a large amount of carbonate ions in a short time.The process is catalyzed by microbial urease, and urea hydrolysis produces carbonate ions, which react with cations in the system (e.g., Ca 2+ ) to form carbonate precipitates with gelling effect [41].Wu et al. [42] used urease enzymes extracted from proteins to produce a biological dust suppressant; the highest coal dust precipitation ratio and the lowest coal dust weight loss occurred when the volume ratio of urease to CACL2-urea solution was 1:3.Microbial communities are more resilient and stable in complex environments than pure bacteria, which can solve the problem of poor performance from pure bacteria.Hu et al. [43]proposed a new method to enrich urea-producing microbial communities from seawater under non-sterile conditions and studied the effects of different environmental factors on the urease activity of urea-producing microorganisms, and the effects of different pH on the mineralizing capacity.They analyzed the cohesive properties of microbial consortia for dust suppression, which was applied to sand and dust suppression.In addition, the scholar prepared the dust suppressant with extracellular polymer (EPS) extracted from sludge and studied the effect of different concentrations of EPS on the dust suppression effect.The results showed that the dust suppression efficiency increased with the EPS concentration.In addition, the adhesion effect of polysaccharides was greater during dust suppression [44].As microbial dust suppressants are biased in application in previous studies, the time and maintenance mechanism of the dust suppression effect is still unclear, Geng et al. [45] have analyzed the effective time and maintenance time of wind and rain corrosion resistance after the treatment of coal dust by microbial dust suppressors (MDS), established the coupling relationship between the consolidation characteristics of coal dust and its corrosion resistance, and discussed the key factors affecting the corrosion resistance effectiveness.The results show that the consolidated body of coal dust can be divided into three stages: the initial stage of dust suppression, the peak stage of dust suppression and the decay stage of dust suppression.With the extension of the mineralization process, the crystal morphology, pore characteristics, hardness and thickness of the coal dust consolidated body have changed accordingly.Principal component analysis (PCA) and redundancy analysis (RDA) show that the consolidation characteristics of coal dust are mainly related to corrosion resistance, and hardness, thickness and hydrophobicity have main effects on corrosion resistance.
Unlike microbial-induced calcium carbonate precipitation for the preparation of dust suppressants, Wang et al. [46]used a microbial fermentation method to obtain the fermentation broth from Bacillus subtilis.They purified the target product from the fermentation broth using techniques such as acidification and precipitation.The results of the performance characterization showed that this product had better wettability properties than fatty alcohol polyethylene ethers on coal dust, and at the same time, possessed eco-friendliness and could be used as an environmentally friendly surfactant for dust suppressants.In addition, these scholars also synthesized a dust suppressant by amidating microalgae oil extracted from Chlorella vulgaris.The experiments showed that the product had good wetting performance, and when the temperature, pH, and salinity varied considerably, the product maintained stable interfacial properties under hard water conditions and had good environmental resistance [47].
Microbial dust suppressants do not need to be sprayed repeatedly, but there are problems of difficult storage and expensive and complicated laboratory conditions [13].Therefore, microbial dust suppressants can be used with other green reagents to ensure dust suppression efficiency while improving economic benefits.In terms of application, most of the performance characterization studies of microbial dust suppressants are carried out in the laboratory, and field application experiments can be carried out in the next step.

Performance Evaluation
According to the dust suppression mechanism, the binding performance of the dust suppressant is evaluated in terms of viscosity, compressive strength, wind erosion resistance, hardness of the cured layer, etc.; the wetting performance is assessed in terms of surface tension, dust reduction time, penetration depth, etc.
The performance evaluation experiments of dust suppression efficacy are divided into physicochemical property experiments and application effectiveness experiments [48].The experiment on physical and chemical properties allows for the observation of the structural characteristics of the main components of the dust suppressant.Scanning electron microscopy (SEM) was utilized to observe the microstructure of the dust suppressant and the morphology of the curing layer after combination with dust particles [49].The functional group changes and internal structure mechanism of dust suppressors were observed by Fourier infrared spectroscopy (FTIR) and X-RD.The thermogravimetric method was used to determine the thermal stability of the dust suppressant.The dust suppression effect of the dust suppressant is mainly evaluated by viscosity, wind erosion resistance, dust suppression efficiency, moisture absorption, and evaporation resistance.To further verify the environmental friendliness and safety of dust suppressants, they can be characterized by pH, degradation rate, corrosion rate, and toxicity.The economy is reflected by cost calculation.In addition, Luo et al. [50]pointed out that the penetration resistance can better evaluate the inhibition effect of dust suppressants on coal dust.
On this basis, Li et al. [51]constructed a comprehensive evaluation index system for chemical dust suppression performance by considering the dust suppression performance, environmental safety, and economic efficiency of chemical dust suppressants.It includes wetting performance, moisture absorption performance, binding performance, annual cost per unit area, pH value, chemical toxicity, chemical corrosion and so on.

Prospect
At present, the research and development of dust suppressants are mainly centered on the two aspects of eco-friendly and economically feasible, aiming to achieve the best dust suppression effect without polluting the environment.With the wide application of bio-organic materials in the preparation of dust suppressants, the problems of energy consumption and environmental pollution have been alleviated to a certain extent, which has a more significant development prospect.However, there are still problems, such as the complexity of the modification process, the dust suppression mechanism is not clear, and future research can be carried out in the following areas: (1) Exploring new materials Further research should be conducted on bio-organic materials that have not yet been developed and used while strengthening the resourceful use of organic waste and structural modification.Through chemical, physical, biological, and other modification methods so that the materials can be used in the production of dust suppressants for different environmental conditions and different locations.Secondly, research into the dust suppressing mechanism of bio-organic materials should be strengthened.
(2) Improving economic benefits Modification processes such as graft copolymerization and microbiological methods are more complex, and research into more convenient synthesis processes can be optimized.Strengthen the research on combining bioorganic materials with harmless chemical reagents or other dust suppression methods to reduce the preparation cost.At the same time, the negative impact of synthetic products on natural ecology can be reduced.
(3) Improving application performance Due to the complexity of actual environmental conditions, there is a certain difference between the laboratory results of dust suppression product development and the actual application effect, and relevant stability studies for different environmental sites should be strengthened to further improve dust suppression efficiency.
(4) Establishing unified norms and standards It is necessary to establish a unified comprehensive evaluation standard system for applying dust suppressant products to facilitate the comparative study of the performance of different dust suppressant products.

Figure 1 .
Figure 1.Three kinds of dust suppression principle schematic diagram.(a)The wetting mechanism; (b)The cohesion mechanism; (c)The solidification mechanism.

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Preparation of dust suppressants from natural products.
3.4.Protein-based dust suppressantProtein-based macromolecular materials can retain water and induce agglomeration of dust particles