生物膜滴滤床内温度及其分布特性对废气净化性能的影响

对不同温度下，陶瓷球填料生物膜滴滤塔净化低浓度有机废气的降解性能以及填料床内温度分布进行了实验研究，实验结果表明：填料床内微生物生长环境温度对微生物酶活性影响很大，从而造成温度对滴滤塔净化性能的显著影响.微生物酶活性最高时的温度为30℃，最高滴滤塔净化性能所对应的温度在30～40℃.在滴滤塔顺流操作条件下，滴滤床内温度沿气液流动方向升高;在进口碳源浓度一定时，滴滤床内沿气液流动方向的温升随着液体流量的减小和气体流量的增大而升高;废气进口浓度及系统操作方式对滴滤床温度分布也有显著影响.

Effects of temperature and its profile on purification performance of biotrickling bed for waste gas treatment

The effect of temperature on the purification performance of trickling biofilter for treating toluene waste gas was investigated experimentally.The results showed that temperature in trickling biofilter bed had a significant influence on purification efficiency.As the inlet temperature of circulation water increased from 10℃ to 60℃, the purification efficiency of trickling bed had a maximum value corresponding to a temperature within 30—40℃.For verifying the effect of temperature on purification efficiency, the experiments for the activity of toluene dioxygenase were conducted at various temperatures of culture fluid.The results of enzyme activity experiment showed that ambient temperature had a great effect on the microorganism enzyme activity for toluene degradation.There existed a maximum enzyme activity at the culture fluid temperature of 30℃, which was coincident with the purification experiment.The temperature profile in the packed bed of trickling biofilter was also measured in the experiments.Under co-current operation mode,the temperature of trickling biofilter bed increased gradually in gas and liquid flow directions which indicated that the metabolic biodegradation of the organic pollutants was an exothermic process.The temperature rise between the outlet and the inlet of trickling biofilter increased as the circulation liquid flow rate decreased and that of waste gas increased.A higher inlet toluene concentration led to a higher temperature rise.Meanwhile, it was also found that the operation mode had a significant effect on temperature profile in the trickling biofilter.