Publications: Peer-reviewed journal articles (by staff)
N2O emissions during microalgae outdoor cultivation in 50 L column photobioreactors
Plouviez M, Shilton A, Packer MA, Guieysse B 2017a. N2O emissions during microalgae outdoor cultivation in 50 L column photobioreactors. Algal Research 26: 348-353.
DOI link here
This study investigated the potential environmental significance of nitrous oxide (N2O) emissions from outdoor microalgal cultivation. Chlorella vulgaris, Neochloris sp., and Arthrospira platensis were cultivated in 50 L pilot scale photobioreactors (PBRs) operated in fed batch mode and fed with either nitrate (NO3−) or ammonium (NH4+) as the nitrogen (N) source. When NO3−was supplied as N-source, Neochloris sp., and C. vulgaris cultures emitted 50.0–14,200 nmol·N2O·m− 2·h− 1 (36 days of cultivation, n = 136, median = 2220 nmol·N2O·m− 2·h− 1) and 9.60–38,000 nmol·N2O·m− 2·h− 1(90 days of cultivation, n = 332, median = 4050 nmol·N2O·m− 2·h− 1), respectively. Based on the emissions representing 25–75% of the data recorded from C. vulgaris fed NO3− (1500–8000 nmol·N2O·m− 2·h− 1), N2O emissions factors were estimated as 0.1–0.4% of the N input load of 25 g·N·d− 1. Further monitoring of C. vulgaris cultures showed that N2O emissions were positively correlated to biomass concentration (R2 = 0.77) and light intensity (R2 = 0.57). Nitrous oxide emissions were not detected when C. vulgaris was cultivated using ammonium as N-source (32 days of cultivation, n = 84), or when A. platensis cultures were cultivated with NO3− as N-source (36 days of cultivation, n = 90). The use of ammonium as N-source or the selection of appropriate algae species could therefore provide simple N2O mitigation strategies.