Thermophilic biofiltration of methanol and α-pinene

Biofiltration systems utilizing thermophilic (55 degreesC) bacteria were constructed and tested for the removal of methanol and alpha -pinene - two important volatile organic compounds (VOCs) in the forest products industry. Thermophilic bacterial mixtures that can degrade both methanol and alpha -pinene were obtained via enrichment techniques. Two bench-scale thermophilic biofiltration systems (1085 and 1824 cm(3)) were used to examine compound removals at different residence times, with influent concentrations of 110 ppmv methanol and 15 ppmv alpha -pinene. At a residence time of 10.85 min, the smaller system had removal efficiencies of > 98% for methanol, but only 23% for alpha -pinene, The larger system was operated with the same parameters to evaluate residence time and surfactant effects on compound removals. At a residence time of 18.24 min, both methanol and alpha -pinene removal rates were greater than or equal to 95%, However, alpha -pinene removal dropped to 26% at a residence time of 6.08 min; methanol removal was not affected. Subsequent addition of a surfactant mixture increased alpha -pinene removal to 94% at the shortest residence time. No residual alpha -pinene was detected with the support medium Celite R-635, indicating that the surfactant may increase mass transfer of alpha -pinene.