Experimental investigation of lab scale solar powered Electrodialysis system with corrugated membrane configuration

Abstract

An experimental laboratory-scale setup of a solar-powered electrodialysis (ED) water desalination system is investigated in this study. The introduced ED system maintains a coupled configuration of corrugated membranes for the first time. The corrugated membrane configuration allows for increasing saline water's flow velocity fluctuations, especially near the membrane surfaces. As a result, the flow turbulence and mixing at the membrane surfaces are promoted, and therefore, higher rates of ion exchange can be attained. The acquired concentration of dilute water was measured at the steady-state operation over a diversity of system parameters: input voltage (4–12) volts, flow rates (5–22 mL/s), and feed concentrations (15–35 g/L). The optimal current efficiency (CE) value was obtained at 70% with a flow rate of around 15mL/s and feed concentration of around 30g/L. High CE percentage values were obtained (60–70%) within the ED system, which indicates that the process of ions transfer through the exchange membranes is effective even if higher feeding flow and concentrations are applied. Regarding the obtained salt removal (SR) percentage values, the present ED model showed a practical operation scenario where an optimal salt removal value of 35% was achieved within 15 minutes. The findings in this study concluded that the present ED system is superior in desalinating saline water when compared to other ED systems in the literature. The energy demands required to power the current ED system are fully supplied by a photovoltaic solar panel. A larger scale of the current ED setup could be useful in the regions that suffer from the lack of freshwater while potential access to renewable energy sources is available, especially in off-grid areas.