Treatment of dynamic VOC mixture in a trickling-bed air biofilter integrated with cyclic adsorption/desorption beds

摘要

A dual-fixed adsorption system involving a two-step cycle, i.e., adsorption and desorption was evaluated for dampening load fluctuation of a mixture of volatile organic compounds (VOCs)-toluene, styrene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK). The cyclic beds successfully performed its function as a buffering unit for the fluctuating inlet loadings. When the employed loading did not exceed the critical loading of 34.0 g/(m3 h), the integrated system maintained consistent 99% removal efficiency regardless of the fluctuation in feeding conditions prior to the cyclic adsorption beds. However, the performance of a standalone biofilter (control biofilter) fluctuated with the fluctuation of the feeding conditions. Under loadings exceeding the critical loading capacity, the integrated system showed much higher and more stable performance than the control system although it could not maintain consistent 99% removal efficiency. The cyclic beds could also act as a feeding source during starvation periods of the system which greatly enhanced the re-acclimation time for the biofilter and at the same time will regenerate the adsorber beds.