Mesoporous carbonaceous materials for single and simultaneous removal of organic pollutants: Activated carbons vs. carbon nanotubes

This research investigates the capabilities of various mesoporous carbonaceous materials for water treatment. First, the adsorbents were tested without prior modification. Then, they were doped with anionic surfactant to assess the feasibility of simultaneous pollutant removal (surfactant-surfactant and surfactant-dye). The choice of adsorbents allowed three levels of comparison (i) internal vs. external surface area, (ii) powdered vs. nanotubes, and (iii) unmodified vs. modified adsorbents. Thus, for the removal of both pollutants, the adsorbents presenting higher porous volume were more efficient. Intraparticle mesoporosity of the activated carbons (ACs) was slightly better than the one generated in the carbon nanotube (CNT) agglomerates. In addition, results revealed that the cationic dye removal was better performed using the raw materials, with the highest efficiency for CNT (578 mg/g). Besides, the anionic surfactant-loaded materials, although showing less adsorption capacities (382 mg/g for one of the modified ACs), still presented competitive performances. For the case of cationic surfactant removal, the modified adsorbents showed better adsorption capacities, especially for the AC "MESO 1", as the uptake efficiency went up from 262 to 302 mg/g. Overall, "MESO 1" and "CNT" were proved to have good potentialities for both single and successive removal of organic pollutants.