Optimization Test Of Multi-Strain Flocculate Coal Slurry And Fractal Dimension Research

Coal slurry is industrial wastewater which in the process of wet-processing in the coal preparation plant. At present, the organic polymer flocculant and inorganic flocculant are mainly to be used to accelerate the flocculation and settlement speed of coal slurry, but these two kinds of flocculants are chemical products, can cause adverse effects to the environment. The efficient and environmental friendly coal bioflocculant is applied to the coal slurry, which has a very important and far-reaching significance.In this thesis, the Bacillus subtilis and Aspergillus fumigatus are applied to the coal slurry flocculation test, which have good flocculation to sewage treatment. Use the regression curve to create a mathematical model by uniform test, to optimize the strains producing flocculant best culture conditions. Create coal slurry pH, coagulant aid dosage, microbial flocculant dosage of each factor with coal slurry transmittance between the mathematical model, to find the optimized culture conditions of Bacillus subtilis and Aspergillus flocculation of the best combination of technology. The co-flocculation tests are carried out by Bacillus subtilis and Aspergillus fumigatus, looking for the best combination of synergistic enhancement efficiency. The study of the morphology of biological flocculation are carried out, to find a correlation between floes fractal dimension and the coal slurry transmittance.The results show that, Bacillus subtilis flocculates coal slurry best transmittance is83.1%, the optimal culture conditions of the quantity of sucrose is2.95%, the quantity of yeast extract is0.78%, the quantity of sodium glutamate is4.44%, the quantity of K2HP04is0.10%, the quantity of MgSO4is0.025%, the quantity of NaCl is0.05%, the value of pH is8.0, the table speed is132r/min, Aspergillus fumigatus flocculates coal slurry best transmittance is81.6%, the optimal culture conditions of the quantity of sucrose is3.27%, the quantity of NaNO3is0.5%, the quantity of K2HP04is0.05%, the quantity of KCI is0.07%, the quantity of MgSO4is0.05%, the quantity of FeSO4·7H2O is0.001%, the value of pH is8.2, the table speed is161r/min, Bacillus subtilis flocculates coal slurry to get the optimum combination, the value of coal slurry pH is6.6, coagulant aid dosage is2.3ml, flocculant dosage is1.9ml, Aspergillus fumigatus flocculates coal slurry to get the optimum combination, the value of coal slurry pH is7.9, coagulant aid dosage is3.0ml, flocculant dosage is2.2ml, Bacillus subtilis and Aspergillus fumigatus synergy to flocculate coal slurry best transmittance rate is92.3%. In the tests of Bacillus subtilis and Aspergillus fumigatus flocculate coal slurry, which have a strong correlation between floc fractal dimension and coal slurry supernatant turbidity, floc fractal dimension as the main control indicators to achieve the quantitative control of flocculant.Through the microbial flocculant of biochemical reactions, microbial flocculant extracts are analyzed by FTIR and scanning electron microscope (SEM), the XRD composition analysis of coal, coal slurry flocs are analyzed by scanning electron microscopy (SEM) and study of coal biological flocculation morphology, analysis of the microbial flocculants flocculating mechanism is the result of the physical and chemical processes, which include the characteristic absorption, chemical reaction, electrical neutralization and enmeshment, among them with "adsorption bridge" give priority to, multi-strain synergistic for "adsorption bridge", etc have significantly enhanced effect.