固定化硫杆菌对硫化氢的脱除研究

Removal of Hydrogen Sulfide by Immobilized Thiobacillus sp.

筛选驯化得到一株具有较高脱硫活性的嗜中性硫杆菌,建立以木屑为固定化载体的生物反应器,研究其处理H2S废气的效果。实验表明,木屑是固定床生物反应器中的良好吸附载体。当通气速率范围为6～18 L.h-1,反应器可达到一个临界进气负荷并获得530 g.m-3.h-1的最大脱除负荷(脱除率为80%);而在21～36 L.h-1的高气速下,则无明显的进气负荷临界点。对于SO42-生成情况的实验研究发现,进气硫负荷一定时,SO42-浓度随通气速率升高而提高;通气速率一定,进气硫负荷在小于450 g.m-3.h-1的范围内时,SO42-生成浓度较高;而在大于450 g.m-3.h-1的较高范围,SO42-生成浓度低,H2S被大量氧化为S0,是单质硫回收的较优范围。利用Michaelis-Menten方程,建立脱除H2S的宏观动力学模型,并利用非线性拟合进行动力学预测,预测结果与实验数据的相似度R2均在0.95以上。

A type of bioreactor using wood sawdust as solid support inoculated with Thiobacillus sp.was developed for the removal of H2S in waste gases.The bacteria were isolated from a hot spring in Sichuan province.The results showed that wood sawdust provided high bacteria adsorption capacity.The maximum removal capacity was 530 g·m-3·h-1（removal efficiency of 80 %） for gas flow rates in the low rage of 6 ~ 18 L·h-1.However,in the high gas flow rates of 21 ~ 36 L·h-1,there was no evident critical point of inlet S-loading.The effect on the production of SO42-was also studied.The concentration of SO42-was increased as gas flow rate increasing at the constant inlet S-loading.And when the gas flow rate was constant,the concentration of SO42-was high at low inlet S-loading（ 450 g·m-3·h-1）.On the contrary,if the inlet S-loading was higher than 450 g·m-3·h-1,the production rate of SO42-was extremely low and the conversion products were mainly sulfur.Thus the range is helpful to recover elementary sulfur.The removal rate of H2S in the bioreactor was modelled using a modified Michaelis-Menten type model.Good non-linear regression coefficients of R2（ 0.95） between experimental data and the predicted curves were found.