生物滴滤塔装置脱硝效率优化改进实验

针对生物滴滤塔系统脱硝效率偏低的问题,在原实验室装置基础上,对滴滤塔系统进行改进,并模拟燃煤烟气的特性,考察了重金属离子、氧气含量以及强化剂对净化效果的影响,并探究了生物滴滤塔系统对锅炉非稳定运行工况的适应性。结果显示:烟气内的重金属离子对微生物具有较强的抑制作用,其中As离子和Pb离子对体系微生物组成的毒性影响最大,Zn离子的影响最小;氧气含量对脱硝效率影响的研究结果表明,系统含氧量越低,脱硝效率降低幅度越大;强化剂组合结果表明,亚硝酸钠+Fe(II)EDTA的组合,强化效果最为明显;生物滴滤塔脱硝系统对锅炉非稳定运行工况适应能力较差,系统停运再启动,停运1周之内,系统经过10 d可以恢复至原来的性能,如果停运12 d以上,系统恢复则长达30 d。根据研究结果,为中试研究提出优化及研究方向建议。

IMPROVEMENT EXPERIMENT ON DENITRATION EFFICIENCY OF BIO-TRICKLING FILTER

The denitrification efficiency of the biotrickling filter system was lower.On the basis of the original trickling filter,the system was improved,and the characteristics of coal-fired flue gas were simulated.The effects of heavy metal ions,oxygen content and the strengthening agent on the purification efficiency were studied and the adaptability of the biotrickling filter system to the unstable operation of the boiler was also discussed.The results showed that heavy metal ions in flue gas had strong inhibitory effect on microorganism,the toxic effect of As and Pb ions on the microbial composition of the system were the highest,and the effect of Zn ions was the least;the effect of oxygen content on denitrification efficiency showed that the lower the oxygen content was,the greater the reduction of denitration efficiency was;the results of the enhancer combination showed that the strengthening effect of the combination of sodium nitrite + Fe (Ⅱ) EDTA was the most obvious.The biological denitrification system had poor adaptability to the unstable operation of the boiler.The system could be restored to the original performance after 10 days when the system was shut down and restarted within a week.If the outage was more than 12 days,the system recovery was up to 30 days.According to the results of the study,the optimization and research direction of the pilot test could be provided.