Experimental Research On Removing Sulfur Dioxide Of Flue Gas With Biomembrane

With the development of biology catalyzing, biology desulfurizing technology which is advanced and economical has become a hotspot on the study of flue gas desulfurizing technology, so it is imperative to develop smoke desulfurizing technology suitable to the situation of China. In trickling bio-filter, desulfurizing by Thiobacillus ferrooxidans combined with inorganic chemistry and microbiology elements, sulfur dioxide in flue gas can be removed effectively. The paper has respectively studied factors influencing the growth of free-bacterium and immobilizing bacterium of Thiobacillus ferrooxidans. The factors influnencing desulfurizing rate ,such as SO₂ inlet density ,entry gas velocity and spraying rate, has also been discussed in this paper.The suitable growth condition of free-Thiobacillus ferrooxidans has been found by nephelometery at first. The results of experiments indicated that bacterium grown well and life-cycle was shorter(about 36h) under the condition: culture temperature 28 ℃, initial pH=2.34, inoculum 15%(v/v), culture medium 100mL/250mL(v/v).Hanging bio-membrane experiment included two steps: in cultivating box and in trickling bio-filter. When free-Thiobacillus ferrooxidans grown well, bio-membrane began to active rapidly after inoculating two cycle continuously with ceramic rasching rings. During the course of hanging bio-membrane in cultivating box beforehand, bio-membranes were compared with coal ash powder, ceramic rasching rings and argil particle as carrier respectively. The study indicated that bio-membrane grown better on argil than on the other two carriers. After 3 days' hanging bio-membrane in trickling bio-filter , the number of free-Thiobacillus ferrooxidans has no change nearly and hanging bio-membrane completed; 5 days later the oxidation rate of Fe²⁺ kept 0.2 g · L^-1 · h^-1, and desulfurizing rate reached more than 99% after domesticating by lower density SO₂ which was pressed into trickling bio-filter.As for desulfurizing experiments, desulfurizing rate is higher than 95% when aerating SO₂ density was less than 2000mg/m3, and dominant 75% when it was less...