Correlations that allow determination of gas film mass transfer coefficients (kGat , kGaw) and liquid film mass transfer coefficients (kLaw) for packing materials used in biofilters and biotrickling filters for air pollution control are presented. Lava rock, polyurethane foam cubes (PUF), Pall rings, porous ceramic beads, porous ceramic Raschig rings, and various compost–woodchips mixtures were...

We investigate the two-dimensional packing of extremely prolate (aspect ratio alpha=L/D>10) granular materials, comparing experiments with Monte Carlo simulations. The average packing fraction of particles with aspect ratio alpha=12 is 0.68+/-0.03. We quantify the orientational correlation of particles and find a correlation length of two particle lengths. The functional form of the orientation...

Formaldehyde is a dangerous compound that must eliminate from contaminated air. Different methods exist for removal of pollutants from the air that among them, the biological processes attracted a great deal of attention. Removal of formaldehyde from the contaminated air was investigated in three laboratory-scale biofilters packed with different materials (a mixture of compost and woodchips, th...

Structured packing has been widely used because of large surface area that makes possible columns with high capacity and efficiency. The large surface area also contributes to fire hazards because of hydrocarbon deposits that can easily combust and promote combustion of the thin metal packing materials. Materials of high surface area that can fuel fires include reactive metals, such as titanium...