The Screening And Breeding Of High Effective Bacteria And Research On Biodesulfurization By The Strain

The biodesulfurization technology (BDS) of coal combined the strongpoins of biological method and physical method.owing to having the virtues of low craftwork cost, little energy consumption, simple flow,mild reaction condition and clean circumstance, the biodesulfurization method will have a wide application foreground.On the Background of short supply on International Energy and low utilization also high cost of domestic energy source, we take the research progress and achieve ment in here and abroad to set about and pointed out the importance of developing biodesulfurization. The status, existing problems and development of this technology was studied. On this basis, carrying out research in the screening and breeding of high effective bacteria for coal desulfurization and desulfurization test and trying to find out a new technology which fits our country.But the oxidation efficiency of iron pyrite in coal by microbe greatly depends on the bacterial survival environment and the low activity limited their application to the practical desulphurization process. Selecting oxidation bacteria which has high oxidation efficiency and fast multiplication is the key point to the biodesulfurization technology. In this paper, change the quality and survival environment of the microbe, transform the mineral property and establishment the mathematic model was carried out in investigation proceed . Mutagenic selection of Thiobacillus ferrooxidans by ultra- violet radiation was carried and screening the bacteria of high effieiency named 2~# mut- ation. Take the anteroposterior growth curve and desulfuration rate to Compared and find 2~# mutation has comparatively fast multiplication.and the time entering the logarithm growth from 43h decurtate to 30h. Take the 2~# mutation to desulfurization process of coal and the optimum conditions were designed by the response surface methodolo gy. In order to determine the optimized experiment condition, some important parameters, such as initial pH, temperature,coal particle size, coal slurry concentration and inoculation were firstly selected by single-factor tests The results showed that the optimum conditions were initial pH:2.0, temperature:30°C, coal particle size: 100, coal slurry concentration:75g/L; inoculation: 10%. According to the Plackett-Burman center-united experimental design principles, the method of response surface analysis with 5 factor s and 3 level s was adopted. The factors influencing the desulfuration rate were determined by means of regression analysis and response surface was graphed with the extraction rate of iron pyrite polysaccharide as the response value yield to the optimized experiment condition. The best desulfuration rate was 60.64% which was predicted by the model. Considering the practically control, we revise the optimized experiment condition as initial pH: 2.0, temperature: 30°C, coal particle size:80, coal slurry concentration: 85g/L; inoculation: 10%. Three tests were undertaken in these conditions to surveyed practical desulfuration rate was 60.53% which was compared by the theory predictive value and the proportional error was less than 2%. Hence the desulfuration parameter which was optimizated by response surface methodology was accurate and reliable and also has practical value.The finding of this article may offer the basic data to the biodesulfurization technology development and also offer some directions to utilize and extract the coal of high sulphur or save energy sources and so on.