Thermocatalytic membrane distillation for clean water production

Abstract

Natural water bodies and treated wastewaters contain an increasing variety of organic micropollutants with a negative impact on ecosystems and human health. Herein, we propose an integrated process based on membrane distillation and advanced oxidation, in which thermal energy is simultaneously used to drive the permeation of pure water through a hydrophobic membrane and to activate the generation of reactive oxygen species by a thermocatalytic perovskite, namely Ce-doped strontium ferrate. At a feed temperature of 65 °C, our thermocatalytic distillation apparatus can effectively retain and degrade bisphenol A, as model pollutant, while producing distilled water at the constant rate of 1.60 ± 0.03 L h−1 m−2, over four continuous runs. Moreover, the membrane makes degradation faster by concentrating the pollutant during filtration. Our technology is effective in the production of pure water without creating a toxic concentrate, it relies on simple process design, and it does not require high pressure or additional chemicals. In addition, it can potentially work continuously driven by renewable thermal energies or waste heat.