pH、接种量及固形物含量对氧化亚铁硫杆菌LX5煤炭生物脱硫的影响

Effect of pH,inoculation and coal burden on bio-desulfurization of coal by Acidithiobacillus ferrooxidans LX5

高硫煤燃烧释放SO2污染环境。采用摇瓶实验,以FeS2驯化的嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)LX5为供试菌株,研究了pH、接种量及煤粉数量对菌株LX5进行生物脱硫的影响。实验结果表明,在15 d的反应周期中反应液的起始pH为2.0、2.5、3.0和4.0时,菌株LX5的脱硫效率分别为43.1%、73.3%、61.9%和37.3%;将菌株LX5的接种量控制为5%、10%及15%时,其脱硫效率分别为44.2%、68.1%及72.2%;将煤粉含量调整为5%、10%及15%时,LX5的脱硫效率分别为73.1%、72.2%及56.3%。摇瓶实验确定的最合适的生物脱硫条件是:培养液起始pH为2.5,LX5接种量为培养液体积的10%,煤粉加入量为培养液质量的10%。在5 L序批式反应器进行煤炭生物脱硫的启动实验,研究表明,反应15 d后煤炭脱硫率达到69.2%,而煤中黄铁矿硫的脱硫率可达78%。

Great attention has been paid to the air pollution caused by combustion of high sulfur coal. Biodesulfurization performances of Acidithiobacillus ferrooxidans LX5 at various pH, inoculation and coal burden were evaluated through batch experiment. In a strong acid culture for 15 days, when initial pH were 2.0, 2.5, 3.0 and 4.0, the desulfurization efficiency by strain LX5 quickly reached 43. 1% , 73. 3% , 61. 9% and 37.3% , respectively. When the batch cultures were carried out 5, 10 and 15 mL of bacterial suspension, the maximum desulfurization efficiencies by strain LX5 were 44.2% , 68. 1% and 72.2% , respectively. Different coal loads had strong influence on the bio-desulfurization performance of strain LX5. The maximum desulfurization efficiencies under the coal loads of 5% , 10% and 15% were 73.1% , 72.2% and 56.3% , respectively. The optimal conditions of bio-desulfurization by LX5 were initial pH of 2.5, inoculation of 10% and loads of 10% , respectively. A mean desulfurization efficiency of 69.2% , especially for pyrite sulfur removal efficiency of 78% were achieved in a 5 L sequencing batch reactor.