Experimental study on enhancing the yield from stepped solar still coated using fumed silica nanoparticle in black paint

The present experimental study deals with the utilization of fumed silicon oxide nanoparticle in black paint at a varied concentration (10–40%) coated on the absorber plate of stepped solar still for augmenting the freshwater yield. The critical parameter for enhanced evaporation depends on the water temperature. From the experimental investigation, it is found that the temperature of the water and absorber are influenced by the absorption rate and the utilization of fumed silicon oxide nanoparticles in black paint which increases the temperature. The average temperature of water and absorber is higher with an optimized concentration of nanoparticle of 20% with black paint is increased by 10.2 and 12.3% respectively whereas, with further increase in nanoparticle concentration with black paint exhibited no significant improvement. Results also showed that the total yield from the solar still is improved by 27.2, 34.2, 18.3, and 18.4% for 10, 20, 30 and 40% respectively while compared to that of ordinary black paint.