Moving towards Valorization of Biowastes Issued from Biotrickling Filtration of Contaminated Gaseous Streams: A Thermochemical Analysis-Based Perspective

Abstract

This paper investigates the valorization potential of two biowaste types resulting from biotrickling filtration of volatile organic compounds (i.e., ethanol) and carbon dioxide from air by co-immobilized microalgae and compost heterotrophs, which were either attached on polypropylene spheres or entrapped within the alginate beads. In this regard, biomass samples from the surface of the packing spheres (S1) and the waste alginate beads (S2) underwent thermal and energy characterization via thermogravimetry and calorimetry techniques as a screening step for establishing some possible biomass valorization pathways. The heat release capacity (HRC) values for the samples S1 and S2 were 95.67 J/(g·K) and 44.11 J/(g·K), respectively, while the total heat release (THR) values were 11.03 kJ/g and 3.64 kJ/g, respectively. The results of this study indicate that the S1 biomass could be suitable for undergoing thermal decomposition processes-based applications, while the S2 biomass could have a potential application for improving flame retardancy of some materials. These findings show that the biowaste issued from such air biotreatment can become a valuable resource for different applications instead of being disposed of. Further research referring to the implementation of these solutions for the development of the final applications is needed.