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

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%。

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

Great attention has been paid to the air pollution caused by combustion of high sulfur coal. Bio-desulfurization 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.