Biofiltration of odorous fume emitted from recycled nylon melting operations.

This study aimed to develop a biofilter packed only with fern chips for the removal of odorous compounds from recycled nylon melting operations. The fern chip biofilters could avoid the shortcomings of traditional media, such as compaction, drying, and breakdown, which lead to the performance failure of the biofilters. A pilot-scale biofilter consisting of an acrylic column (14 cm2 x 120 cm height) packed with fern chips to a volume of around 19.6 L was used for the test. Experimental results indicate that oxygen- and nitrogen-containing hydrocarbons as well as paraffins were major volatile organic compounds (VOCs) emitted from thermal smelting of recycled nylon at 250 degrees C. With operation conditions of medium pH of 5.5-7.0, empty bed retention time (EBRT) of 6-12 sec, influent total hydrocarbon (THC) concentrations of 0.65-2.61 mg m(-3), and volumetric organic loading of 0.05-0.85 g m(-3) hr(-1), the fern-chip-packed biofilter with nutrients of milk, potassium dihydrogen phosphate, and glucose could achieve an overall THC removal efficiency of around 80%. Burnt odor emitted from the smelting of the recycled nylon could be eliminated by the biofilter.