Joule heat enabled efficient In-situ regeneration of carbon nanotubes as model adsorbents

• More efficient Joule heating production were obtained at higher voltage. • Nearly 100% Benzoic acid (BA) was desorpted from CNTs film at an optimium voltage. • Electrothermal regeneration has extremely lower energy consumption. Thermal-desorption has been considered as an environmentally friendly approach to regenerate the exhausted adsorbents to achieve a sustainable adsorption process. However, the traditional thermal desorption method suffers from the demanding contradiction between the desorption efficiency and energy consumption. Herein, we developed an efficient and economical thermal-desorption strategy based on the Joule heating by employing a three-dimensional carbon nanotubes (CNTs) film as the model adsorbent. The features of CNTs film with negative temperature coefficient endow the impressive heat production for the electrical resistance decreased from 341.0 Ω at 25.7 °C to 36.7 Ω at 76.5 °C. The desorption ratio of target pollutant (i.e., benzoic acid) in the continuous Joule heat induced thermal desorption process could be reached to 93.2% with the energy consumption of 0.25 kW h, which is two orders of magnitude lower than that in the indirect thermal desorption process for one ton of wastewater at the specified scale. This study proposed a green and energy-efficient strategy for thermal regeneration, and provide a method guidance for the development of green regeneration technology.