Construction Of In-situ Thermally Responsive Materials And Research On New Thermal Regeneration Technology

Adsorption technology has been widely used in wastewater industries whileexhausted adsorbents need to be regenerated frequently.Except traditional solvent-based competitive regeneration,thermal regeneration has received widespread attention due to its solvent-free and none-secondary-pollution characteristics.However,conventional thermal regeneration is carried out with hot water steam,namely,the adsorbent is heated up by indirectly contacting with high-temperature water vapor,which usually suffers from high energy consumptionand the heat-sensitive adsorbent damaging,causing problems such as deterioration of mechanical strength and reduction of the adsorption capacity.Thus,a method that turn the traditional “outside heating” into “self-heating” of the material to avoid energy loss while improving heat utilization would be highly desirable.The excellent electrical and thermal properties of carbon nanotubes(CNTs)have advanced them to receive more extensive attention from domestic and foreign scholars as adsorbent.Meanwhile,CNTs are also a broadband blackbody material,with a maximum light absorption ratio of over 99%.According to this,we assembled a three-dimensional CNTs thin film,and investigated the Joule heating and light heating effect on regeneration of CNTs adsorbent.The main contents and conclusions are as follows:The CNTs membranes treated with hydrochloric acid(70 ℃)have good electrothermal properties and better desorption effect revealed on the contaminants,for which the temperature can reach up to105.6℃ at 10 V,and 98% of benzoic acid(BA)molecules can be driven from the film.And then,we verified the generality of the electrothermal desorption law viatarget on desorption of other contaminants.Furtherly,we continued to verify the feasibility of photothermal desorption through the blackbody absorptivity of CNTs,in this way suppressing the external power supply in the electric heating process.And the photothermal desorption ratio of BA can reach 93.8% under irradiation of infrared light in a batch reactor.Meanwhile,we have constructed a millimeter-scale resin by employing CNTs in polystyrene(PS)to enhance mechanical strength and practical application.And a cumulative desorption ratio of 56.2% was reflected under halogen lamp irradiation.In short,this article proposes and verifies a new rapid in-situ thermal regeneration concept and method based on electric heating and photothermal effects.It expands the path of thermal regeneration and provides scientific and technological support and method guidance for the development of green regeneration technology.