Accelerating the desalination of seawater and elimination of cosmetic contaminants from tap water by depositing zinc copper vanadate microparticles on solar evaporators

Abstract

Black garbage bags (BGB) and car air filters (CAF)) were recycled and used to elaborate interfacial solar evaporators, also named as recycled materials evaporator (RME). The RME evaporator desalinated seawater at a maximum evaporation rate and evaporation efficiency of 3.19 kg∙m-2∙h-1 and 80.1%, respectively, under natural sunlight. Later, the RME evaporator was completely coated with copper zinc vanadate (CZVO) microplates (RME-F-CZVO evaporator). Other two RME evaporators were made, one of them had printed a circle of CZVO particles at its center (RME-C-CZVO evaporator), while the second one had nine small circles of CZVO microparticles distributed on its surface (RME-D-CZVO evaporator). The highest evaporation rate (3.61 kg∙m-2∙h-1) and evaporation efficiency (90.4%) were reached for the RME-C-CZVO evaporator. Printing the CZVO microparticles with circular geometry at the center of the evaporator maximized the accumulation of heat, which in turn, accelerated the evaporation of the seawater. This effect was confirmed by thermographic images. In addition, the evaporators reduced the water vaporization enthalpy by 27-36.3%, which favored the steam generation at lower temperatures. Also, the evaporators were utilized for the purification of stream water (contaminated with organic compounds) and tap water contaminated with cosmetics (skin foundation and blush). The results indicated that 97–99% of the cosmetics was removed from the water after the evaporation treatment, and 95–99% of the total dissolved solids were eliminated as well. This investigation reveals that low-cost solar evaporators made of recycled plastics/cellulose can desalinate seawater or could serve to eliminate cosmetics with complex composition from the tap water.