Air stone-induced microbubble agitation: a strategy for solar still performance enhancement

Sustainable solar-based desalination systems have become a significant global energy challenge, and integrating energy storage technologies is crucial in addressing this challenge. Solar stills, a simple and sustainable method for converting impure water into potable water, have recently gained considerable attention from researchers. However, one of the major setbacks of this renewable energy system is its low efficiency. This study aims to enhance the distillate yield of solar stills by agitating the natural convection process within the still using air bubbles, which can contribute to improved energy storage and utilization. Porous air stones were positioned within the inner basin to generate microbubbles. A single basin, single slope solar still was used to investigate the effect of air bubbles on productivity. Additionally, the impact of varying numbers of air stones on productivity was studied by repeating the experiment with two, three, and four air stones. The results indicate that the yield of the solar still increases with the inclusion of an air stone due to enhanced heat transfer within the still. An increase in 15.6%, 28.7%, 9.3%, and 5.4% in the distillate output of the solar still was observed with the inclusion of one, two, three, and four air stones, respectively, compared to the conventional one. The results of the study demonstrate the potential of using air bubbles to augment the efficiency of solar stills and provide a practical and economically viable solution for desalination. Graphical abstract: (Figure presented.)