Photothermal activation of peroxydisulfate for simultaneous solar evaporation and water purification using non-powered capillary fabric

Solar evaporation is a promising method for water purification, but it often faces challenges such as scale formation of organics after feed water evaporation and low efficiency in evaporation. In response, we created a dual-function system based on the photothermal active peroxydisulfate (PDS) technique. The system serves both double-sided evaporation to improve evaporation efficiency and simultaneous removal of organic contaminant scale accumulation. Wastewater containing PDS is extracted by capillary force through a photothermal fabric, evaporating on both surfaces under sunlight. Concurrently, the thermal energy generated during the steam generation process can break the O-O bond of PDS, generating sulfate radicals (SO4·-) that decompose organic pollutants. The design achieves a rapid evaporation rate of 5.47 kg m−2 h−1 and a high solar efficiency of 89.9 % under sunlight irradiation (4000 W/m²). Additionally, it demonstrates a 99.8 % RhB removal efficiency in concentrated brine. Importantly, highly concentrated brine can be collected without solid-salt accumulation. This development enhances the potential of solar distillation for wastewater treatment. [Display omitted] •Developed dual-function system for evaporating and purifying salt organic wastewater.•Utilization of capillary forces ensures low energy consumption in continuous pumping.•Enhanced evaporation efficiency via dual side evaporation and novel steam collection.•The controlled flow management effectively mitigates the accumulation of solid salt.•Coupled advanced oxidation technology and effectively control wastewater pollution.