Research On SO₂ Removal With Optimum Efficient Thiobacillus Ferrooxidans

Coal-fired boilers has filled the air with plenty of sulfur dioxide into the atmosphere, which has lead to heavy pollution. Sulfurous smog and acid rain not only have very bad influence on people’s health, but also cause incalculable damage to society and the environment. As traditional methods of flue gas desulfurization(FGD) have many disadvantages, including highcost, secondary pollutions. Using biological desulfurization becomes one of the most popular research topic in recent decades. This paper uses Bio-trickling flue gas desulfurization with efficient Thiobacillud ferrooxidans(T.f). The work in this issue and main conclusions we made from the research are as follows.1. The pure T.f are enriched by 9K culture medium, and the behavior during their growth cycle is analyzed detailedly. T.f need about 42 hours to complete their growth cycle, which reach exponential phase after culturing for 18 hours. Reaching stationary phase needs about 30 hours. The change of p H in the medium, the number of polysaccharides and protein in the extracellular polymeric substances(EPS) all can reflect their growth rhythm well.2. Corona discharge treatment on screening out efficient T.f is suggested in this study, which is the best innovation in this experiment. When discharging spacing is 5mm and the time is 5min, the growth cycle of treated T.f is 12 hours shorter than before, which is about 30 hours now. The average rate of oxidation of ferrous ions reaches 0.32g/(L·h), increased by 45.5%. The number of polysaccharides and protein increase dramatically at 18 th hours, coming to the maximum 356.9μg/(1010cells), 240.4μg/(1010cells). The treated bacterial metabolic capacity is stimulated,and the vitality of bacteria is enhanced greatly.3. The treated T.f are used to desulfurize after the biofilm form in self-designed bio-trickling filter. The biofilm forms 4 days earlier than the original T.f in bio-trickling filter. Also, the range of removal of sulfur dioxide concentration in flue gas increases obviously. When the liquid medium sprays at a rate of 24L/h, the concentration of Fe2+ is about 0.9g/L, the temperature keeps 30℃, p H equals 2.5 and the concentration of sulfur dioxide is 3000mg/m3, the cycle of desulfurization is 2 days shorter by the treated T.f than original T.f. In conclusion, the treated T.f are better in sulphur removal efficiency. The result of this research provides some new ideas for biological desulfurization, and it is significant to develop semi-works production and create new technologies applying in practice.