抑尘剂(降尘剂)是提高水介质防尘降尘效率的重要途径，但目前煤矿应用的抑尘剂普遍为化学抑尘剂，存在表面活性较低、成本较高，降解性差、对环境有污染等问题。为此，提出研制高表面活性、天然环保的新一代抑尘剂——生物抑尘剂。研发了枯草芽孢杆菌发酵合成生物抑尘剂BDS(Biological Dust Suppressant)的工艺，并采用响应面分析法和Design Expert软件分析了菌株高产的最优发酵条件;采用X射线晶体衍射和红外光谱技术探究了BDS的晶体结构和官能团结构;采用表面张力仪测试BDS溶液的表面张力，研究其在不同温度、酸碱度和含盐量条件下的界面性能和环境耐受能力;采用界面流变仪和扫描电镜测试BDS的润湿性能，并与化学抑尘剂AEO(Alcohol ethoxylate)进行了比较。结果表明:对枯草芽孢杆菌进行活化、优选和培养可得到含有BDS的发酵液，然后采用酸化沉淀、超声萃取和减压蒸发方法对发酵液进行提纯，即可提取出BDS;在温度A=37.56℃、酸碱度B=7.99、摇床转速C=220 r/min、接种量D=2.17%、装液量E=59.89 mL的发酵条件下，BDS产量最大，达2.09 g/L;BDS结构上表现为各向同性，是一种具有长烷链和多肽结构的非晶体活性物质;BDS的临界胶束质量浓度为30 mg/L，较低的使用浓度即可将水的表面张力降至27 mN/m以下，在较大的环境参数变化范围内(温度≤70 ℃、酸碱度5~9、NaCl质量分数≤15%)，溶液表面张力仍保持在27~30 mN/m;6 mg/L(1/5临界胶束质量浓度)的BDS溶液与煤尘的接触角仅为11.19°，其润湿能力与500 mg/L(临界胶束质量浓度)的AEO溶液相比提高63.5%，表现出优异的润湿性能。研究工作为破解传统抑尘剂面临的表面活性和润湿能力较弱、生物降解性和环保性不足等难题提供了借鉴。

Dust suppressant is an important way to improve the efficiency of water medium for dust control,and common dust suppressant used in coal mines is generally chemical dust suppressant.With the low surface activity,higher cost,poor biodegradability,as well as environment pollution and other issues associated with chemical dust suppressant,this paper aims to develop a new generation of dust suppressant,biological dust suppressant,with high surface activity and natural environment friendly.A technological process for synthesizing biological dust suppressant (BDS) from bacillus subtilis by fermentation has been developed and optimized with response surface optimization method and Design Expert software to explore optimal fermentation conditions of strains.X ray diffractometer and Infrared spectrum were used to explore the crystal type and functional group structure of BDS.The surface tension of BDS solution was tested by surface tensiometer to study the environmental tolerance under different temperatures,acidity and salinity conditions,and the wettability of BDS was compared with Alcohol ethoxylate (AEO) measured by interface rheometer and SEM.The results of the research demonstrated as follows:firstly,the fermentation broth received by activation,optimization and culture of Bacillus subtilis is purified to obtain BDS by acidizing precipitation,ultrasonic extraction and vacuum evaporation.Secondly,the BDS can be produced to the maximum capacity of 2.09 g/L under the conditions of temperature=37.56 ℃,pH=7.99,rotating speed=220 r/min,inoculant=2.17%,and liquid loading=59.89 mL.Thirdly,the BDS is an amorphous active and structurally isotropic substance with long alkane chains and polypeptides.Fourthly,the surface tension of water can be reduced below 27 mN/m with the critical micelle concentration of 30  mg/L,and BDS can still maintain the surface tension in the range of 27-30 N/m under the changeable conditions of temperature below 70 ℃,pH between 5-9 or NaCl content below 15%.Fifthly,the superior wettability of 6  mg/L BDS,which can reduce the wetting angle of coal dust to 11.19°,is increased by 63.5% compared with 500  mg/L AEO.This research for biological dust suppressant synthesizing by microbial fermentation provides a new way of thinking and scheme to solve the problem of weak surface activity and insufficient environmental protection faced by traditional dust suppressants.