Retrofitting a thermoelectric-based solar still integrated with an evacuated tube collector utilizing an antibacterial-magnetic hybrid nanofluid

Providing sufficient potable water using solar energy is a promising method; however, existence of legionella bacteria, causing pneumonia is prevalent in the solar systems operating at low temperature range, such as solar stills. This work is the first report of applying the antibacterial property of a hybrid nanofluid for disinfection, and using its magnetic property for increasing the heat transfer rate, simultaneously. In this research, the performance of a modified single slope solar still using a thermoelectric-equipped channel integrated with a concentrating evacuated tube collector applying an antibacterial-magnetic Ag@Fe3O4/deionized water hybrid nanofluid was examined experimentally, and was compared to that of a traditional solar still. The results indicated that both productivity and energy efficiency were improved by integrating the thermoelectric cooling channel solar still with the concentrating solar collector and adding Ag@Fe3O4 nanoparticles to the fluid. The modified solar still integrated with the solar collector utilizing the proposed hybrid nanofluid at a volume concentration of 0.08% ameliorates the daily productivity and energy efficiency rates by respectively 218% and 117% compared to a traditional solar still. Also, the cost of producing freshwater by the proposed modified solar still is about 0.019 ($/L/m2) and the payback period was calculated as 369 days.