Screening Of Carbon Tetrachloride High Efficiency Degradation Strains And Study On Its Degradation Rules

The article studies the carbon tetrachloride of difficult degradation for object and 131 strains is separated from the pollution soil sample. They are screened and cultured on the carbon tetrachloride as the only carbon source. The results showed finally that survival ability of the white-rot fungus is strongest in includes in selective medium which contains the carbon tetrachloride.This paper study that the effect of multi-factor comprehensive conditions on the white-rot fungus growth. Simultaneously the article study that the environmental condition influences the white-rot fungus to biodegrade the carbon tetrachloride. The test finally obtained optimum scheme for mycelium growth and to degrade the carbon tetrachloride.Through the white-rot fungus ferment experiment and calculate various model parameters the mycelium growth kinetics model was established: C_x(t)=0.091exp(0.0718t)/[0.976+0.0241exp(0.0718t)] Extracellular polysaccharide formation kinetics model: P_x(t)= 0.0477+0.8318C_x(t)+0.105ln[0.976+0.024exp(0.0718t)] Base consumption kinetics model: C_s(t)= 14.107-3.023C_x(t)-0.856ln[0.976+0.024exp(0.0718t)] The degeneration kinetics model which the white-rot fungus degrades the carbon tetrachloride: Y (t )= -0.1054t+3.129Through the packing column simulates static biodegeneration experiment in shallow layer sandy loam, the research discovered that a certain amount carbon tetrachloride can stimulate the white-rot fungus's growth. It can become dominant fungi under the pollutant induction. The plowing can enhance effectively the dissolving oxygen and raises the conductivity. Under the same condition, plowing degeneration rate is 1.45 times of not plowing. The increase dispersant can also enhance obviously the biodegradation rate. Rice husk as dispersant, its degradation rate is highest, the final degeneration rate is 93.9%. Similarly, the overhigh inoculation amount will also reduce the degeneration rate unceasingly.In the packing column simulation shallow layer sandy loam's dynamic degeneration, through carbon tetrachloride vertically migrates in leaching process, we study the effect of each factor on carbon tetrachloride degradation. Experiment shows that the degradation rate of sampling holes change with time. The change is shown from low to high. Simultaneously experiments showed that temperature is one of the important factors to influence degradation rate. Through the calculation, the degradation rate will increase 14-23% when the temperature increases 4 degrees Celsius in a certain range.In the dynamic experiment, the degeneration rate of five kind of dispersant is higher than the sandy loam (control) in packing layer. The rice husk's degeneration ability is most excellence and the degeneration rate is 81.2%. The regular ploughing can also enhance the contact opportunity with microorganism and the carbon tetrachloride, increases porosity, maintains the temperature, promote degeneration. The experiment shows that the degeneration rate can enhance two times through ploughing processing.Analyzes from the dynamic viewpoint, the suitable glucose concentration (25g/L) can promote mycelium's degeneration, the overhigh concentration will increases the osmotic pressure of cell, the cell of dehydration will be inhibited. Simultaneously, the soil viscosity is increased, the carbon tetrachloride isl increased adsorption and detention, reduces contact opportunity with microorganism's, thus will affect its degeneration rate.