Influence of pH pH is an important factor to

Regarding the surfactant-loaded adsorbents, investigated to assess the possibility for a simultaneous (dual) adsorption process, the related results showed that the adsorption capacities decreased when compared with the raw materials. For instance, the removal capacity of MESO 1 went down from 480 to 317 mg/g for CNT and CNT-SDBS respectively. Such behaviour could be explained at two levels. First on the external surface, MB MI-773 (SAR405838) were proven to be linked to CNTs via π–π interactions, implying that MB aromatic plane lies flat on CNT surface to fulfil maximum orbital overlap [22]. As the surface has already been occupied by the SDBS, the engagement of such interactions is quite feeble. In the case of electrostatic adsorption, however, MB molecule tends to be linked by one end, so it is likely to be tilted on CNTs negatively charged surface [23] (anionic SDBS for this study). Thus, this tilted orientation (i.e., space-saving conformation) will allow MB molecules to be adsorbed with the help of the anionic charge provided by the surfactant already present on of the CNT surface.