Study on performance of floating solar still using pumice stone as photothermal material

In this article, the rate of freshwater production in the floating solar still using pumice stone is investigated. In this device, the use of a one-way valve has given this device the ability to direct lake or pool water into its basin in a controlled manner. By placing a type of photothermeral material (pumice stone) in the basin of the solar still, the efficiency of the device and the amount of fresh water production increase compared to the simple device. All experiments were performed in Semnan in Iran. The temperature, productivity, and exergy efficiency of this water softener without the use of limestone and modified with limestone were compared. Finally, a cost analysis wass performed to check the economic status of the device. The results showed that the daily production rate of the floating solar still modified with pumice stone in autumn and spring was 113 and 219 cm3, respectively, and for the conventional floating solar still was 82 and 189 cm3, respectively. The costs of producing each liter of fresh water for a floating solar still modified with pumice stone and the conventional floating solar still for the autumn were 0.0847 and 0.104 $/m2, respectively, and in the spring, this cost for the floating solar still modified with pumice stone is 0.043 $/m2.