Investigation of a biosystem based on Arthrospira platensis for air revitalisation in spacecrafts: Performance evaluation through response surface methodology Gabriela Soreanu a, * , Igor Cretescu a , Mariana Diaconu a , Corneliu Cojocaru b , Maria Ignat b, c , Petrisor Samoila b , Valeria Harabagiu b a "Gheorghe Asachi” Technical University of Iasi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Department of Environmental Engineering and Management, 73 D. Mangeron Blvd, Iasi, 700050, Romania b "Petru Poni” Institute of Macromolecular Chemistry Iasi - Romanian Academy, 41A Grigore Ghica Voda Street, Iasi, 700487, Romania c "Alexandru Ioan Cuza” University, Faculty of Chemistry, 11 Carol I Blvd., Iasi, 700506, Romania highlights  A. platensis is screened as a microalgae candidate for environment control in space.  Air contaminated with multiple trace gaseous contaminants is addressed.  Next-generation lighting technology is involved as illumination alternative.  Biosystem diagnosis is efficiently performed via mathematical tools.  More than 80% contaminants removal can be achieved. article info Article history: Received 21 July 2020 Received in revised form 24 September 2020 Accepted 25 September 2020 Available online 4 October 2020 Handling Editor: Y Yeomin Yoon Keywords: Photobioreactor Arthrospira platensis Sustainable biosystem Mathematical modelling and optimization Life support in space Air biotreatment abstract Arthrospira platensis is featured as a promising microalgae candidate for the development of the bio- systems for air revitalisation in spacecrafts and life support in space. An enhanced configuration of a sparged type photobioreactor (PBR), containing 5 L of A. platensis culture, which was equipped with an external LED lighting tube around the reactor, was used in this study. The PBR was operated under dynamic conditions (0.5 L/min) with synthetic air containing CO 2 (400, 900, 1400 ppm) and other gas traces (NO 2 1 ppm, SO 2 2.5 ppm, acetic acid vapours 1 ppm), at various light intensities (1.5, 2.5, 3.5 klux), according to an experimental design. The removal of gas traces (NO 2 , SO 2 and acetic acid vapours) was below the detection limit (e.g. above 90% removal efficiency), while the removal of CO 2 ranged between 69% and 85%, depending on the initial CO 2 concentration and the light intensity. Thus, the system is able to roughly decrease the contaminant concentration from 1 ppm to below 0.1 ppm for NO 2 , 2.5 ppm to below 0.1 ppm for SO 2 , 1 ppm to below 1 ppb for acetic acid vapours and from 1400 ppm to 370 or from 400 ppm to 60 ppm for CO 2 . The system performance was thus subject to mathematical modelling and optimization in terms of CO 2 removal efficiency and CO 2 elimination capacity, which were also corroborated with the power consumption for illumination. © 2020 Elsevier Ltd. All rights reserved. 1. Introduction The use of biotechnologies for air treatment is an environmental-friendly option that is recognised for its potential to compete with classical (physical-chemical) technologies in terms of both sustainability as well as cost-efficiency (Soreanu and Dumont, 2020; Kennes and Veiga, 2013; Devinny et al., 1999; Menard et al., 2011). Typical application refers to air treatment in biotrickling filters, biofilters and bioscrubbers, by using specific microorgan- isms for the removal of relatively high concentrations (e.g. from hundreds to thousands of ppm) of various volatile organic com- pounds or inorganic gaseous contaminants. A more recent approach refers to the use of microalgae for air treatment, which is * Corresponding author. E-mail addresses: gsor@tuiasi.ro, gsor10@yahoo.ca (G. Soreanu). Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere https://doi.org/10.1016/j.chemosphere.2020.128465 0045-6535/© 2020 Elsevier Ltd. All rights reserved. Chemosphere 264 (2021) 128465