A Solar-Driven System Enabling Simultaneous Water Recovery, Heavy Metal Recycling, and Electricity Generation

Abstract

The global depletion of natural resources has provided the impetus for the development of low-cost, environmentally friendly technologies to recover valuable resources from wastewater. In this study, we present a novel solar-driven thermal-electric cogeneration system (STECS) that, by virtue of solar energy alone, can recover metals from metal-containing wastewater and generate electricity while recovering fresh water by interfacial evaporation. STECS consists of three parts: a simulated electroplating wastewater chamber, a titanium dioxide/carbon fiber (TiO2/CF) photoanode, and a platinum sheet cathode. We demonstrate that solar-irradiated STECS recovers copper from simulated copper-containing wastewater at the platinum sheet cathode interface at a rate of 2.6 g m–2 h–1. A maximum power density of 910 mW m–2 (at one solar intensity) was also generated. In addition, the water evaporation rate of STECS can reach 1.2113 kg m–2 h–1 under one solar intensity condition. Our research explores a novel water treatment technology utilizing solar energy to achieve two birds with one stone, demonstrating that the system can simultaneously achieve wastewater reduction, metal resource recovery, EDTA degradation, and process power production, providing a promising solution and blueprint for alleviating global water/energy shortages while achieving sustainable development.