嗜酸氧化亚铁硫杆菌脱煤矸石中硫影响因素的筛选及条件优化

Factor screening and condition optimization of desulfurization of coal gangue with Acidithiobacillus ferrooxidans

采用Plackett-Burma(P-B)和Box-Behnken(B-B)设计相结合的方法筛选和优化嗜酸氧化亚铁硫杆菌(A.ferrooxidans)脱除煤矸石中硫的主要影响因素和实验条件。首先,通过P-B设计从pH、煤矸石粒度、煤矸石添加量、Ag+浓度和煤矸石类型等因素中筛选影响脱硫率的主要因素。然后,在确定使用新鲜矸石条件下,对另外4个主要因素采用BB设计和响应面分析进行脱硫条件优化。研究结果表明,pH、煤矸石粒度和Ag+浓度对脱硫率具有显著影响,其影响程度为煤矸石粒度>pH>Ag+浓度。利用Design Expert软件建立起脱硫率与影响因素之间的二次回归方程模型,通过求解方程得到最优脱硫条件为pH(3.0)、煤矸石粒度(124μm)、煤矸石添加量(56 g/L)、Ag+浓度(100 mg/L),在该条件下实际脱硫率达88.62%,与模型预测值接近,说明可以利用该模型来分析和预测矸石的脱硫效果。

Plackett-Burman（ P-B） and Box-Behnken（ B-B） sequential design strategy were used to screen and optimize the main influencing factors and the related condition of desulfurization of coal gangue with Acidithiobacillus ferrooxidans（ A. ferrooxidans）. Firstly,using P-B design to screen the main factors influencing on desulfurization rate of coal gangue from pH,coal gangue size,the adding amount of coal gangue,Ag＋concentration and coal gangue type et. al. Then,under the condition of using fresh coal gangue,the B-B design and response surface analysis were employed to optimize the desulfurization condition for the other four main factors. The results showed that pH,coal gangue size and Ag＋concentration had significant effect on the coal gangue＇s desulfurization rate,and the influence extent followed coal gangue size pH Ag＋concentration. By solving the quadratic regression equation between desulfurization rate and main impact factors obtained by Design Expert software,the optimum desulfurization conditions were pH of 3. 0,coal gangue size of 124 μm,the adding amount of coal gangue of 56 g/L,and Ag＋concentration of 100 mg/L. Moreover,the actual desulfurization rate by using the optimized condition was up to 88. 62%,which was in close agreement with the predicted value. Based on these results,the obtained model could be used to analyze and forecast the desulfurization of coal gangue with A. ferrooxidans.