Treatment of ?-pinene-contaminated air using silicone oil-coated perlite biofilter

Two biofilters equal in size were filled with perlite for treatment of ?-pinene-contaminated air. The per-lite used for one of the biofilters was partially coated with silicone oil to make the surface of the particles more hydrophobic. The filters were run at 1.5,2.5, and 5 L/min airflow rate (3.1,1.9, and 0.9-min retention time). The filters were operated for 5.5 months. The results showed that the silicone oil-coated filter performed better at 2.5 L/min with a maximum elimination capacity of 20 g/(m3 h) in comparison with 15 g/(m3 h) for the filter without oil. The efficiency was approximately the same for both filters at 1.5 L/min (40 g/m3 h), whereas it was slightly higher for the without oil filter at 5 L/min [35 g/(m3 h)]. The flow rate was set to 2.5 L/min once more (day 151). The results showed that the elimination capacity had increased to 35 g/(m 3 h) and that the efficiency of both filters was approximately the same. The difference in results between the initial run and the later run at 2.5 L/min is probably depending on that the number of microorganisms had increased during the experiment and that the oil-containing biofilter adsorbed ?-pinene to a higher extent than the biofilter without silicone oil during the start-up period. © 2009 American Institute of Chemical Engineers