Polymeric solid wastes for efficient and stable solar desalination and the outdoor clean water production performance prediction

Abstract

Freshwater shortage and polymeric solid waste pollutions are among the most serious global issues. To address these, we propose a novel strategy that utilizes these polymeric solid wastes to synthesize an interfacial solar evaporator for freshwater production. As one of the typical polymeric solid wastes, the poly (vinyl formaldehyde)(PVF) sponge is selected to demonstrate this strategy as the substrate to fabricate the polypyrrole-coated PVF sponge (PPy/PVF sponge). Benefiting from the intermittent salt accumulation strategy, PPy/PVF sponge enables stable seawater desalination with an excellent evaporation rate of 1.15 kg m-2h−1 under 1 sun. The calculated and experimental results show that the intermittent salt accumulation strategy enables most interfacial solar evaporators to be operated stably in seawater. In addition, we design an outdoor device containing the PPy/PVF sponge with a maximum water production rate of 4.85 kg m−2 daily. Based on the outdoor performance data, we propose a novel method to predict the outdoor water production rate worldwide through an artificial neural network, which is also the first multi-objective method to predict the outdoor performance of interfacial solar evaporators, as we know. It is estimated the device containing 10 m2 of PPy/PVF sponge could meet at least 17–26 people’s daily drinking water needs. In conclusion, this work proposes a novel method for the resource utilization of polymeric solid wastes and gives new insights into efficient and stable solar seawater desalination.