Chlorine-free Extractions of Mixed-Culture Polyhydroxyalkanoates Produced from Fermented Sewage Sludge at Pilot Scale
Gaia Salvatori, Sara Alfano, Andrea Martinelli, Marco Gottardo, Marianna Villano, Bruno Sommer Ferreira, Francesco Valentino, Laura Lorini
Abstract
High Resolution Image Download MS PowerPoint Slide In this study, various conventional and innovative methods were investigated for the recovery of polyhydroxyalkanoates (PHA) from a single batch of biomass produced at a pilot scale from mixed microbial cultures (MMCs) and fermented sewage sludge as a feedstock. Sustainable chlorine-free methods using NaOH and/or H 2 O 2, as well as extraction in nontoxic ethyl acetate, were analyzed. Interestingly, the combined treatment of biomass with NaOH and H 2 O 2 solutions demonstrated good recovery (70 wt %) and high purity (92 wt %) of the polymer in small-scale trials. Moreover, when the coupled treatment was performed on a larger biomass quantity (approximately 200 g), it achieved high purity and recovery yield (93 and 88 wt %, respectively), indicating the feasibility of this extraction method on a larger scale.