The effect of the adsorbent medium on the freshwater productivity and desalination efficiency in solar-powered surface desalination systems and step ponds has been systematically evaluated in this work. Four ponds of the same size but with different adsorbent media were used in the experiment: Ceiba pentandra charcoal, Gliricidia sepium, Schleicera oleosa, and a control pond without adsorbent media. In addition to the volume analysis and desalination efficiency, the surface area analysis (SAA) device was also tested. The test results showed that, in general, Gliricidia sepium charcoal produced a high water volume of 120 mL/h and a desalination efficiency of 21.96%. This is because Gliricidia sepium charcoal has the highest surface area, pore volume, and pore distribution. Compared with previous studies that focus on energy requirements, energy saving, and high efficiency in constructing complex ponds, this paper proposes a simple construction pond that utilizes solar energy, thereby achieving higher efficiency, maximizing desalination volume, and improving the sustainability of the energy-water-environment relationship.
