Renewal of nanofibers in Chlorella fusca microalgae cultivation to increase CO2 fixation

Abstract

This study explored strategies to increase the CO₂ fixation ability of microalgae by renewing polymeric nanofibers in cultures of Chlorella fusca LEB 111. Nanofibers composed of 10% (w v^-1) polyacrylonitrile (PAN)/dimethylformamide (DMF) containing 4% (w v^-1) iron oxide nanoparticles (NPsFe₂O₃) were added to photobioreactors. The nanomaterial was renewed in the test cultures as follows: renewal only on day 7; renewal only on day 15; or renewal on both days 7 and 15 (i.e., double renewal). The highest biomass concentration (2.53 g L^-1) and CO₂ biofixation rate (141.5 mg L^-1 d^-1) were obtained by cultivating with double renewal, resulting in values 21.6% and 23% higher, respectively, than those obtained by cultivation without renewal. The application of nanofiber renewal in the cultivation of C. fusca LEB 111 shows the potential to increase CO₂ biofixation, which may contribute to reducing the atmospheric concentrations of this main greenhouse gas intensifier.

Keywords: Adsorption; Carbon dioxide; Mitigation; Nanofiber renewal.