Study On Preparation Nanoscale Humic Acid By Alkali-solution And Acid-isolation

With the nanoscale material technology development, Nanoscale humic acid of a new multifunctional fine organic material is born with particle size between1～100nm. In view of specific property of humic acid, nanoscale humic acid is expected to be used in agricultural, industrial and medical treatment in the future. This paper is focused on the preparation of nanometer technology and the application of crystalling adjusting agent in the preparation of nanoscale organic material. According to the grade of the weathered coal and the requirements of the product, the nanoscale humic acid was prepared by the alkali-solution and acid-isolation and higher shearring technology, firstly, the paper studies the preparation of nanoscale humic acid by the alkali-solution and acid-isolation and higher shearring technology, in the preparation technology research, the optimum condition to prepare nanoscale humic acid such as crystalling adjusting agent(single and blend), the optimum body precursor process conditions and drying method was obtained through single factor and orthogonal experiment. Secondly, the penetration curve of the nanoscale humic acid adsorption benzene, toluene mixed gas was studied and the dynamics theory of adsorption equilibrium was forecast. Finally, the antibacterial property was achieved by antibacterial experiment of nanoscale humic acid to escherichia coli, staphylococcus aureus. The main research results are as follows:(1) The preparing process of nanoscale humic acid is feasible by alkali-solution and acid-isolation and higher shearring technology using weathered coal as raw materials, and the optimum process conditions are as follows:the reaction time was150min, the reaction temperature was60℃, ammonia concentration was25.00%, the solid-to-liquid ratio was1:10, the shear rate was2800r/min, the addition amount of crystalling adjusting agent for lauryl benzene sulfonic acid sodium (LAS) and A17(ratio of1:2) was1.5‰of the total reaction solution, vacuum drying was0.08MP, drying temperature was100℃, the drying time was4h.(2) The nanoscale humic acid were characterized by XRD, SEM, FTIR, AFM, GPC, laser particle size analyzer, thermogravimetric analysis (TGA), and specific surface area analyzer; The results showed that:(a) the nanoscale humic acid had narrow diameter distribution and good crystallization, and ultrasonic shock way was used for the dispersion of the product, which had greatly improved conglomeration of the powder and product particle size, furthermore, the average particle size was60nm, the specific surface area was110.31m2/g, and relative molecular weight was119.(b) the chemical structure of nanoscale humic acid was changed, and the new functional group and the active site increased, meanwhile, surface morphology of the product with spherical structure became smooth, and the product had a good anti-heat performance.(3) Adsorption equilibrium of pure component on nanoscale humic acid was basically accord with Langmuir equation, and adsorption capacity of toluene is better than that of benzene, for the multicomponent adsorption, adsorption phenomenon tend to be complex because of interaction and competition between the various components, the results showed that the adsorbed benzene component had been replaced by toluene component with stronger adsorption capacity, and IAST equation was formed on the basis of the thermodynamic models, the average prediction error was less than10%, the prediction error of the total amount was only5%or so.(4) Antibacterial experiment results indicated that:the nanoscale humic acid have good antibacterial property to colon bacillus and staphylococcus aureus, two kinds of bacteria in the antibacterial rate were99.1%and98.6%, and antibacterial properties still has certain permanence.