Abdolahnejad Ali, Mokhtari Mehdi, Ebrahimi Ali Asghar, Nikaeen Mahnaz, Shahi Mohsen Askari, Hajizadeh Yaghoub
Isfahan University of Medical Sciences, Isfahan, Iran.
J Environ Health Sci Eng. 2019 Dec 12;17(2):1017-1027. doi: 10.1007/s40201-019-00416-4. eCollection 2019 Dec.
Biofiltration of hydrophobic and/or recalcitrant volatile organic compounds such as n-hexane is imperfect. In the present study, we applied a hybrid system consisting of a photoreactor packed with scoria granules coated with TiO and a biofilter to improve the removal efficiency of n-hexane from the air stream. The experimental results showed that the hybrid system provided higher removal efficiencies than the single biofilter process with an inlet n-hexane concentration range of 0.11-1 g for empty bed residence times (EBRTs) of 30-120 s in the hybrid system. The removal efficiency of the single biofilter in EBRTs of 30, 60 and 120 s was 10.06%, 21.45%, and 45.98%, respectively. When the photoreactor was included as a pretreatment system (with residence time of 7-27 s) and the overall EBRTs of the system was adjusted to 30, 60 and 120 s, the removal efficiency of the hybrid system was increased to 39.79%, 63.08%, and 92.6%, respectively. The mass ratio of carbon dioxide produced as an indicator for n-hexane degradation in the hybrid system and the biofilter alone was 1.9 and 1.28, respectively. Bacterial community analysis with sequence analysis of 16S rDNA in the biofilter biomass revealed that and as predominant bacterial species were responsible for n-hexane biodegradation. Therefore, the application of the hybrid system is advantageous in enhanced n-hexane removal from the air stream.
对疏水性和/或难降解挥发性有机化合物（如正己烷）进行生物过滤并不完美。在本研究中，我们应用了一种混合系统，该系统由填充有涂覆TiO的火山渣颗粒的光反应器和生物滤池组成，以提高从气流中去除正己烷的效率。实验结果表明，在混合系统中，对于空床停留时间（EBRTs）为30 - 120秒、入口正己烷浓度范围为0.11 - 1克的情况，混合系统比单一生物滤池工艺具有更高的去除效率。在30、60和120秒的EBRTs下，单一生物滤池的去除效率分别为10.06%、21.45%和45.98%。当将光反应器作为预处理系统（停留时间为7 - 27秒），且系统的总EBRTs调整为30、60和120秒时，混合系统的去除效率分别提高到39.79%、63.08%和92.6%。作为正己烷降解指标的混合系统和单独生物滤池中产生的二氧化碳质量比分别为1.9和1.28。对生物滤池生物质中16S rDNA进行序列分析的细菌群落分析表明， 和 作为主要细菌物种负责正己烷的生物降解。因此，混合系统的应用有利于提高从气流中去除正己烷的效率。
