Polyurethane foam medium for biofiltration. I: Characterization

Although biological treatment has been applied successfully to treat waste gases using conventional organic packing media such as compost, there is currently a need for further research on ways to optimize the medium selected. Use of a superior filter-bed medium could overcome or minimize many of the problems encountered in conventional biofilter operation (e.g., medium clogging, difficulty in control of moisture content, and nutrient limitation). In research described herein, polyurethane foam was manufactured and characterized to determine its suitability as a solid support medium for use in gas-phase biofilters. Part I of this paper describes studies conducted to determine the medium's porosity, pore size, head loss characteristics, density, sorption capacity, and chemical resistance. Results are presented that characterize the polyurethane foam medium's properties and suggest how it can be used effectively in treating gas-phase volatile organic compound contaminants. Part II of this paper describes studies conducted to determine the medium's ability to support an active biofilm and to study feasibility of a novel nutrient addition and biomass wasting strategy.