Biodesalination: an emerging technology for targeted removal of Na+ and Cl− from seawater by cyanobacteria.

Minas, K.; Karunakaran, E.; Bond, T.; Gandy, C.; Honsbein, A.; Madsen, M.; Amezaga, J.; Amtmann, A.; Templeton, M.R.; Biggs, C.A.; Lawton, L.

Abstract

Although desalination by membrane processes is a possible solution to the problem of freshwater supply, related cost and energy demands prohibit its use on a global scale. Hence, there is an emerging necessity for alternative, energy and cost-efficient methods for water desalination. Cyanobacteria are oxygen-producing, photosynthetic bacteria that actively grow in vast blooms both in fresh and seawater bodies. Moreover, cyanobacteria can grow with minimal nutrient requirements and under natural sunlight. Taking these observations together, a consortium of five British Universities was formed to test the principle of using cyanobacteria as ion exchangers, for the specific removal of Na+ and Cl− from seawater. This project consisted of the isolation and characterisation of candidate strains, with central focus on their potential to be osmotically and ionically adaptable. The selection panel resulted in the identification of two Euryhaline strains, one of freshwater (Synechocystis sp. Strain PCC 6803) and one of marine origin (Synechococcus sp. Strain PCC 7002) (Robert Gordon University, Aberdeen). Other work packages were as follows. Genetic manipulations potentially allowed for the expression of a light-driven, Cl−-selective pump in both strains, therefore, enhancing the bioaccumulation of specific ions within the cell (University of Glasgow). Characterisation of surface properties under different salinities (University of Sheffield), ensured that cell–liquid separation efficiency would be maximised post-treatment, as well as monitoring the secretion of mucopolysaccharides in the medium during cell growth. Work at Newcastle University is focused on the social acceptance of this scenario, together with an assessment of the potential risks through the generation and application of a Hazard Analysis and Critical Control Points plan. Finally, researchers in Imperial College (London) designed the process, from biomass production to water treatment and generation of a model photobioreactor. This multimodal approach has produced promising first results, and further optimisation is expected to result in mass scaling of this process.

Citation

MINAS, K., KARUNAKARAN, E., BOND, T., GANDY, C., HONSBEIN, A., MADSEN, M., AMEZAGA, J., AMTMANN, A., TEMPLETON, M.R., BIGGS, C.A. and LAWTON, L. 2015. Biodesalination: an emerging technology for targeted removal of Na+ and Cl− from seawater by cyanobacteria. Desalination and water treatment [online], 55(10): selected papers presented at 2015 Desalination for the environment conference: clean water and energy, 11-15 May 2014, Limassol, Cyprus, pages 2647-2668. Available from: https://doi.org/10.1080/19443994.2014.940647

• Presentation Conference Type: Conference Paper (published)
• Conference Name: 2015 Desalination for the environment conference: clean water and energy
• Acceptance Date: Jun 16, 2014
• Online Publication Date: Oct 13, 2014
• Publication Date: Aug 31, 2015
• Deposit Date: Feb 19, 2021
• Publicly Available Date: Sep 12, 2022
• Journal: Desalination and Water Treatment
• Print ISSN: 1944-3994
• Electronic ISSN: 1944-3986
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 55
• Issue: 10
• Pages: 2647-2668
• DOI: https://doi.org/10.1080/19443994.2014.940647
• Keywords: Biodesalination; Osmolytes; Biotechnological screening; Sustainable; Remediation
• Public URL: https://rgu-repository.worktribe.com/output/1147905