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.

Combined Nanofiltration and Thermocatalysis for the Simultaneous Degradation of Micropollutants, Fouling Mitigation and Water Purification

“…The experiments to investigate the thermocatalytic abatement during filtration were performed at a temperature of 50 °C, because our previous studies showed that CSF can catalyze fast degradation of BPA at this temperature [ 20 ]. The feed volume was 1.8 L, a cross flow of 1.6 ± 0.1 m s −1 was applied and the transmembrane pressure was 6 bar.…”

“…Such temperature-permeance dependence in ceramic NF membranes can be explained by considering the change in solvent viscosity and that permeation in micropores occurs by a combination of viscous flow and activated transport [ 24 ]. Hence, the increase of the feed temperature is beneficial for membrane permeance and for the thermocatalytic abatement at the same time [ 20 ].…”

“…Moreover, common biological treatments are not effective for BPA degradation [ 19 ]. On the other hand, we reported full abatement of BPA in water by treatment with CSF perovskite in our previous study [ 20 ].…”

Kinetics of Strontium Carbonate Formation on a Ce-Doped SrFeO3 Perovskite

“…Within the catalytic area, various oxide perovskites have shown thermocatalytic properties regarding the degradation of organic compounds by the formation of reactive oxygen species (oxygen-containing radicals) [5], which can be useful in the removal of micropollutants from wastewater in the future [6]. The catalytic site in perovskites is mainly located in the B-site (transition metal) due to their multiple oxidation states [7], covering, for example Ti [8,9], Fe [10,11], Co [12,13], and Mn [14]. However, doping and tuning the A-site can alter the band gap [15].…”

Ba2TiMnO6 two-dimensional nanosheets for rhodamine B organic contaminant degradation using ultrasonic vibrations

“…One of humanity's environmental issues is the growing worldwide pollution of the water supply caused by climate change, economization, overconsumption, and population growth 1 .…”