Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor

Abstract

Background: In addition to uses in home furnishings and the construction sector, polyurethane foam (PUF) is also prevalent in medical products such as scaffolds and implants. However, these applications raise concerns for human health as the use of this material can result in exposure to the carcinogenic substance 2,4-toluenediamine (2,4-TDA). The objective of this study was to identify easily extracted PUF-residuals and to study the removal of them in a biodegradation experiment including immobilized Trametes versicolor. Ultra-high-performance liquid chromatography-quadrupole/time of flight mass spectrometry (UHPLC-Q-TOF MS) was used in MS and MS/MS-mode to confirm the identities of PUF-related compounds and follow their concentration changes. Results: Except for 2,4-TDA and 2,6-TDA which were confirmed by standards, previously not reported substances were tentatively identified, among them TDA-dimers. These dimers include homodimers, heterodimers containing 2,4-TDA and 2,6-TDA and compounds that are hydroxylated. The experiments that were performed in an acidic fungal culture revealed a not previously described removal of these compounds below the approximate nM detection limit. The mechanisms behind their removal may include biosorption to fungal mycelia, bioaccumulation, use of them as nutrients or extracellular catabolism. Conclusion: The results of this study not only highlight the ease by which harmful compounds were extracted from the investigated PUF-quality which is used in non-medical applications, but also the possibility to use fungal-based methods to eliminate them. This could be facilitated by an initial extraction of PUF (excluding fungi) followed by a removal of the substances with PUF-immobilized Trametes versicolor. The findings in this study may be of interest to further investigate PUF-residuals in products aimed for medical applications.Citation: Åke Stenholm et al., 2019. Removal of toluene diamine and its derivatives from polyurethane foam using immobilized Trametes versicolor. Advances in Environmental Biology 13(2): 17-29.