University of North Dakota, Department of Chemistry, Grand Forks, North Dakota, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2012;47(7):997-1007. doi: 10.1080/10934529.2012.667313.
Removal of gasoline vapors from waste air was investigated in a bench-scale perlite biofilter for three aromatic-to-aliphatic mass ratios (62/38, 92/8 and 44/56) under different loads, varied by changing both the substrate inlet concentration and air flow rate. The measurement of concentration profiles along the bed height allowed for an assessment of interactions between the aromatic and aliphatic fractions of gasoline. Variations in both the inlet concentrations and empty bed residence time significantly influenced the removal of aliphatic gasoline components. Except for the lowest organic loads, the whole biofilter bed was required for achieving an acceptable removal efficiency of aliphatic hydrocarbons. The presence of large amounts of aromatics negatively impacted the removal of aliphatics. By contrast, the aromatic gasoline components were near-completely removed from any mixtures; the bulk of them were degraded in the first (out of three) biofilter section, even at high concentrations of aliphatic hydrocarbons. The observed effect was shown to be due to competitive interactions of aliphatic and aromatic components, which is consistent with the biological steps being rate limiting. Mass transfer, particularly for aliphatic components due to their high Henry's law constants, was shown to be rate-limiting under extreme scenarios, such as low loading rates and EBRT.
研究了在一个小型膨胀珍珠岩生物滤池内，通过改变基质入口浓度和空气流速来改变不同负荷下的三种芳烃与烷烃质量比（62/38、92/8 和 44/56），从废气中去除汽油蒸气。沿床层高度测量浓度分布，评估了汽油中芳烃和烷烃馏分之间的相互作用。入口浓度和空床停留时间的变化显著影响了烷烃汽油成分的去除。除了最低有机负荷外，还需要整个生物滤床才能达到可接受的烷烃去除效率。大量芳烃的存在对烷烃的去除产生负面影响。相比之下，芳烃汽油成分几乎可以从任何混合物中完全去除；即使在高浓度的烷烃存在下，它们中的大部分也会在第一个（三个中的第一个）生物滤池段中被降解。观察到的效果是由于芳烃和脂肪族成分之间的竞争相互作用所致，这与生物步骤是限速步骤一致。传质，特别是由于亨利定律常数高的脂肪族成分，在极端情况下（例如低负荷率和 EBRT）被证明是限速的。
