紫外光解强化生物滤塔去除疏水性α-蒎烯的传质及降解动力学分析

利用紫外光解（UV）作为预处理工艺来强化生物过滤塔（BF）和生物滴滤塔（BTF）对疏水性化合物α-蒎烯的去除,基于试验数据对滤塔内α-蒎烯的传质行为和微生物活性进行了模型和理论分析.Michaelis-Menten动力学分析表明,α-蒎烯在UV-BTF内的气相饱和常数为1.0gm-3,是其在BTF内的20倍,而α-蒎烯在BF内的气相饱和常数略大于UV-BF内相应数值.UV-BTF的理论临界进气浓度为555.22mgm-3,高于其他处理系统.微生物代谢活性和比耗氧速率分析表明,UV-BTF内的微生物世代时间明显缩短,α-蒎烯及其光解产物的最大比耗氧速率分别达到了1.16、0.34、0.41和0.25mgO2mg-1DWh-1,略高于其他处理系统中相应数值的150%-200%.以上模型拟合数据从理论上说明UV光解工艺能减轻α-蒎烯在BTF内的传质抑制效应,进而提高整体宏观去除能力;但是由于BF工艺的自身特性和累积臭氧的毒害效应,UV光解不适合作为BF的预处理工艺.

Mass transfer and degradation dynamics analysis of biofiltration enhanced by ultraviolet photodegradation for the removal of hydrophobic alpha-pinene

Ultraviolet photodegradation（UV） was utilized as a pretreatment to enhance the biofiltration process（BF and BTF） for the removal of hydrophobic α-pinene.Based on the experimental data,the mass transfer behavior and microbial activity were analyzed by the theoretical models.The gas phase saturated constant Km of α-pinene was 1.0 g m-3 in the UV-BTF,20 times than that in the sole BTF;while this value in the sole BF was slightly higher than that in the UV-BF.Fitted by the Ottengraf-van den Oever model,the critical inlet concentration in the UV-BTF was 555.22 mg m-3,which was much higher than that in other systems.Through the analysis of microbial activity and specific oxygen utilization rate,the biofilm in the UV-BTF was much more active,and the maximum specific oxygen utilization rates for α-pinene and its photodegradation intermediates were respectively 1.16,0.34,0.41and 0.25 mgO2 mg-1 DW h-1,slightly higher than 150%-200% of the values in other systems.Such results illustrated that UV photodegradation could reduce the mass transfer inhibition for α-pinene and simulate the growths of microorganisms in the subsequent BTF,thus enhancing the overall removal capabilities.But the UV technology was not a suitable pretreatment for the subsequent BF owing to BF＇s own characteristics and cumulative toxic effects of ozone.