Interfacial Solar Evaporation Toward Efficient Urine Purification and Resource Recovery with Polypyrrole-Based Photothermal Conversion Films

Abstract

Human urine consists of a mixture of water (90~95%) and nutrients, which makes it a potential source of clean water supply and nutrients upon valorization and reclamation. Interfacial solar evaporation technology is a highly competitive method for wastewater purification and resource recovery in rural areas of developing countries. In this work, a series of polypyrrole-based photothermal conversion films were prepared using ferric chloride, where pyrrole was the raw materials, CC and PW as the substrates. Indoor solar water and urine evaporation experiments demonstrated that CCF-MH was the best solution for outdoor solar urine evaporation experiments under an imitation tree structure (without PVC) evaporation system. Outdoor solar urine evaporation experiments found that CCF-MHLS could recover 1.1 kg·m-2 of condensed freshwater (meeting WHO standards for drinkable water) at 7.5 h under a low light intensity. This paper may provide a new platform for low-cost, high-efficient, and large-scale urine purification and resource recovery under real outdoor sunlight irradiation.

Keywords: polypyrrole, Photothermal conversion film, Urine treatment, Resource Recovery, Interfacial solar evaporation