On the Desalination of Saline Waters via Batch Adsorption with Spent TeaLeaves

Desalination is a technology that still needs to take off in scientific research. The current techniques are not appropriate and still demand great investments of money, manpower and space. This study proposes the use of spent tea leaves on the removal of sodium ions from seawater. Although our results do not show a remarkable purification of saltwater (maximum observed adsorption percentage of 8%), but it demonstrates a strong effect of pH, adsorbent mass, salt concentration, presence of other ions and dyes. This indicates that the desalination by using these materials could be tuned and optimized (base-treated GT reached 16% adsorption). Furthermore, column experiments demonstrate that this desalination technique could be taken to automatized systems for the purification of larger water volumes. Instrumental analyses demonstrated that these materials have high heat resistance and appropriate morphological and textural properties, indicating that have appropriate mechanical properties for their use as adsorbents. Lastly, the uptake of sodium ions was improved by the treatment of the tea leaves with diluted acid and bases, indicating their potential as desalinating biomaterials. These results create a new mindset on the desalination as a fertile area that will benefit the society.