Application of photosynthetic microalgae in the direct desalination pretreatment of seawater
Chukwuemeka Samson Ahamefule, Chika Ugwuodo, Priscilla O. Idike, James C. Ogbonna
Abstract
Abstract The abilities of three species of freshwater microalgae to grow in, and desalinate untreated and undiluted seawater were investigated. The salinities of the seawater were reduced from 37.5g/L to 26.25 ± 1.33, 27.19 ± 1.33 and 30.0 ± 0.00 g/L by Desmodesmus subspicatus LC172266 , Desmodesmus armatus LC172263 and Dictyosphaerium spp. LC172264 on the fourth, eighth and tenth week of the experiment, respectively, while the control had no change in the salinity. D. subspicatus cell concentration initially dropped from 1.25 × 10 6 cells/ml to 9.68 × 10 5 cells/ml and then gradually increased to 4.86 × 10 7 cells/ml by the tenth week. With D. armatus and Dictyosphaerium spp., the cell concentrations increased steadily from 1.25 × 10 6 cells/ml to 4.97 × 10 8 cells/ml and 3.25 × 10 8 cells/ml, respectively. There were increases in the pH during desalination by the three species. This demonstrates the halotolerant potentials of these species and their abilities to reduce the salinity of seawater.