Electro mitigation of calcium carbonate and calcium sulfate scaling in an optimized thermal conductive membrane distillation process

•Optimizing the thermal conducting layer improved the desalination performance.•Thermal conducting layer’s thickness, porosity and temperature affect MD performance.•Regular electro-cleaning effectively alleviated calcium carbonate scaling in thermal conductive MD.•Continuous applying a potential on the membrane successfully mitigated the calcium sulfate scaling. Desalination technology can obtain fresh water from brine to alleviate the pressure of global water scarcity. Membrane distillation (MD) is a promising technology for desalination, especially for hypersaline brine. Although the emergence of novel processes enhances the competitiveness of MD in desalination, membrane-based separation technology inevitably leads to membrane fouling, thereby decreasing flux and thermal efficiency. Herein, we prepared an electroactive membrane and using it in an optimized thermal conductive membrane distillation process. Optimizing the thermal conducting layer can improve the desalination performance. Aiming to the typical membrane scaling of calcium carbonate and calcium sulfate, we elucidated the influence of the thermal conducting layer temperature, porosity, and feed velocity on the formation of the foulants. Results showed that the increase in porosity of the thermal conducting layer, the decrease in temperature, and the increase in feed flow velocity were conducive to alleviating the scaling of calcium carbonate and calcium sulfate. Regular electro-cleaning effectively alleviated calcium carbonate scaling, whereas continuous application of a potential to the membrane mitigated the calcium sulfate scaling. The mechanism of electrochemical mitigation of calcium carbonate and calcium sulfate scaling included forming an electric double layer, generating electrostatic repulsion to inhibit the formation of crystals, and changing the pH to dissolve the crystals.