Multifunctional and fully aliphatic biodegradable polyurethane foam as porous biomass carrier for biofiltration

Abstract

Water-blown fully aliphatic polyurethane foam was prepared at room temperature from trimer of hexamethylene diisocyanate and poly(diethylene glycol adipate) diol and post cured at 55 °C. In contrast to aromatic-based PUR foam analog, the produced flexible PUR foam exhibited highly porous structure with open cell content of 94% and average cell size of 700 μm. Therefore, it was subsequently tested as biodegradable cellular carrier of microorganisms (fungus Fusarium solani and bacterium Pseudomonas sp.) for biofiltration. Firstly, tests on enzyme activities (lipase, protease and urease) and utilization of PUR foam as the sole carbon and nitrogen source and determination of degradation products were carried out. Fusarium solani shown much higher both enzyme and degradation activities and higher spectrum of degradation products. Finally, the performance of a biofilter packed with the developed cellular carrier was investigated for removal of a mixture of acetone, propionic acid, ethyl acetate, toluene and α-pinene. Proven sorption properties of PUR foam against all pollutants and a high maximum elimination capacity of 218 ± 33 g m−3 h−1 make the new lightweight biofilm PU carrier suitable for this application due to their multi-functionality.