Biodesalination performance of Phormidium keutzingianum concentrated using two methods (immobilization and centrifugation)

[Display omitted] •Comparison between two treatment methods for Phormidium keutzingianum was studied.•Chloride ion measurements affirmed biodesalination process using P. keutzingianum.•Biosorption and bioaccumulation process was debriefed with salt uptake mechanism.•Osmoregulation experiment confirmed that P. keutzingianum can survive extreme salt. The biodesalination performance of the cyanophycean Phormidium keutzingianum concentrated using two methods (centrifugation and immobilization) was evaluated for the first time at NaCl concentrations of 10, 30, 50, and 70 g/L. In addition, the osmoregulation ability of P. keutzingianum was assessed at high salinities (50, 70, 85, and 100 g/L) over a relatively short time period. The pH, electrical conductivity, and chloride, nitrate, and phycocyanin concentrations were measured during all experiments. The immobilization method of concentration resulted in a chloride removal rate of up to 44 % during the osmoregulation experiment at a salinity of 100 g/L. For the centrifugation method, the chloride removal rate was 26 % on the 20th day of observation for 10 g/L. Thus, the immobilization method resulted in faster chloride ion removal than the centrifugation method. The findings demonstrate that biodesalination efficiency can be enhanced by the use of different P. keutzingianum preparation methods.