Study On Coagulant Aid In Coal Bioflocculation

Flocculation settlement method is most widely used in the process of slime water treatment and lower cost,the method of inorganic flocculant and organic polymer flocculant will cause adverse effect on human health and ecological environment,and the microbial flocculant safe because of its efficient and suitable for large-scale characteristics of bioengineering industrialization become the new direction of the coal slurry flocculation research.Coagulants have a wide range of functions,mainly used to adjust or improve the flocculation structure,increase particle size and specific gravity,promote flocculation sedimentation,but also can effectively reduce the dosage of flocculant,reduce the content of organic matter in water,remove heavy metal ions and other radioactive substances.Currently,the commonly used coagulant aid for microbial flocculation of coal slime water is CaCl2.Due to the presence of Ca2+,it can effectively reduce the surface charge of colloid and enhance the adsorption bridging between microbial flocculant and colloid.On the basis of previous studies on microbial flocculants,the research focus of this paper is to change the coagulant aids required in the process of flocculation,and to investigate the temperature of coal slurry water,the pH of coal slurry water,the concentration of coagulant additives and the amount of flocculant additives.Bacillus subtilis with good flocculation activity was selected as the flocculant producing bacteria and chitosan modified diatomaceous earth and DEAE cellulose were used as flocculant.Experimental research shows that when the content of chitosan in diatomite is 100 mg/g flocculation experiment was carried out by light transmittance value maximum,by single factor experiment that used modified diatomite and bacillus subtilis coal makes up for the first one of the best technology of coal slurry flocculation conditions for slime water temperature is 39?,slime water pH value of 5,modified diatomite content is 0.2 g,bacillus subtilis flocculant adding amount of 1.5 ml,under the condition of the flocculation slime water 30 min can make the light transmittance as high as 84.3%.The modified diatomite was replaced with CaCl2,a commonly used coagulant aid in microbial flocculation,and the light transmittance of the supernatant obtained from the flocculation test of coal slime water under other test conditions was 71.1%.Through single factor experiment that DEAE cellulose and bacillus subtilis cooperate to use about the second coal preparation of slurry flocculation optimum technological conditions for the coal slime water temperature is 25?,the slime water pH value of 7,DEAE cellulose content is 0.25 g,bacillus subtilis flocculant adding amount of 1.5 ml,under the condition of the flocculation slime water 30 min can make the light transmittance as high as 87.3%.The modified diatomite was replaced with CaCl2,a commonly used coagulant aid in microbial flocculation,and the light transmittance of the supernatant obtained from the flocculation test of coal slime water under other test conditions was 67.9%.The experiment shows that the flocculation speed is very fast under the action of cellulose,and the light transmittance of the supernatant can reach 80.6%after the supernatant is settled in the measuring cylinder for 15min,and the settling speed is even with calcium chloride as coagulant aid,but the whole process is long.Determine the specific surface area and modified diatomite and Zeta potential value,the determination result of diatomite specific surface size is not influence the decision of the coal slurry flocculation effect factors,due to the amino groups on chitosan protons,modified diatomite positively charged,easily with the coal slime water of anionic groups combined electrostatic attraction.In the process of cellulose,small particles are firstly condensed into larger flocculation particles,which makes it easier to participate in the bridging action of microbial flocculants.Figure 28 table 23 reference 60...