| Aiming at the defects of high cost and limited treatment effect of water treatment flocculant,organic and inorganic compound flocculant is introduced continuously.The application of crop straw as flocculant with airborne system can not only save cost,but also reduce environmental pollution.At the same time of high efficiency flocculation are prepared by combining some materials with special properties.In this paper,nano-magnetic material Fe3O4 was loaded on cellulose and biochar prepared from straw respectively.These flocculants were compared to characterize their structure and judge their properties.Fe3O4-chitosan-cellulose with PAM was used to treat coal slurry water with better characterization and flocculation effect.The flocculation effect of composite nano-magnetic flocculant was discussed.Based on the fractal theory,the size of the two-dimensional fractal dimension of the floes under different influencing factors was explored,so as to optimize the influencing factors.According to the literature,the best process for preparing nano magnetic Fe3O4 was optimized.Nanometer magnetic Fe3O4 as flocculant was prepared by co-precipitation method and loaded on biochar and cellulose under the action of chitosan as adhesive.Fe3O4-biochar flocculant and Fe3O4-cellulose flocculant were obtained.The flocculant was characterized by XRD,ft-tr,SEM and energy spectrum.The results showed that Fe3O4-biochar flocculant and Fe3O4-cellulose flocculant were successfully prepared and the flocculants obtained had good crystal structure.Fe3O4-chitosan is linked together with biochar and cellulose through hydrogen bond association to form a more stable flocculant structure.The flocculant was characterized by nucleomagnetic structure and regular Fe304-cellulose agglomeration.Biochar contains higher void and specific surface area than cellulose,so Fe3O4 can be better loaded on biochar that adsorb Fe3O4-ehitosan than cellulose.Compare five kinds of flocculant including Fe3O4-biochar,Fe3O4-cellulose,PAM,PAC,PFS to deal with slime water.Under the adscititious magnetic field of 0.25 T,through metallograpHic microscope we can find five kinds of coagulant after coagulation.So we can determine the fractal dimension.The results showed that treatment effects of five flocculants on coal slime water are PAM,Fe3O4-cellulose,Fe3O4-biochar,PAC and PFS in order.The scale invariance and similarity can be known from the fractal dimension theory,so floes also have a high degree of fitting.Using self-made nano magnetic Fe3O4-cellulose with PAM treat coal slime water and then take coagulation experiments to study the Fe3O4-cellulose dosing quantity,PAM dosing quantity,pH,stirring speed and stirring time in order to learn coagulation effect.Through metallograpHic microscope we can detect flocculation body size to measure fractal dimension.The results showed that the fractal dimension of Fe3O4-chitosan-cellulose combined with PAM was significantly higher and the turbidity removal rate was positively correlated with the fractal dimension of magnetic flocculant.The flocculant and coal slurry water suspension mainly pass electrostatic attraction and intermolecular force which weak.But the force can change the electrical properties of the surface of the suspended particles to improve the coagulation effect.Nano-magnetic NFC+PAM can better strengthen the flocculation effect,which can introduce traditional flocculation into the field of magnetism and expand the scope of magnetism in order to reduce the dosage and save flocculant every year.The annual cost of flocculant can be saved by 126,600 yuan. |
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