As-synthesized multi-walled carbon nanotubes for the removal of ionic and non-ionic surfactants

Preparation of Magnetic Multi-Walled Carbon Nanotubes to Adsorb Sodium Dodecyl Sulfate (SDS)

“…Indeed, desorption of anionic SDS molecules into the solution took place gradually. This confirms the earlier conclusion explaining that SDS adsorption on MMWCNTs is due to both ionic and hydrophobic interactions between MMWCNTs and SDS molecules (33,36).…”

“…A rise in adsorbent concentration and thereby an increase in the available adsorption sites of adsorbents led to the enhancement of adsorption efficiency (37). Given that MWCNTs is a hydrophobic adsorbent, the hydrophobic sections of SDS can easily adsorb to the adsorbent sites (36). It should be noted that the influence of independent variables on MWCNTs were studied, as well.…”

“…Moreover, in acidic pH, the connection between hydrophobic chains of the surfactant and adsorbent will improve, while in alkaline pH due to the presence of OH-groups, a competition will arise between these groups and the anionic surfactant for adsorbing on the surface of positively charged adsorbent and thus, a remarkable reduction in adsorption efficiency will be observed (3,36). …”

The role of adsorption in the photocatalytic decomposition of Orange II on carbon-modified TiO2

“…The obtained results are connected to the influence of pH on the ionization state of titanium dioxide. It is also worth mentioning PZC, which is defined as the pH at which the surface exhibits a net surface charge of zero (pH PZC ) [41]. Based on the pH PZC measurements for C1B-TiO 2 , C2B-TiO 2 and TiO 2 , which were 5.41, 4.76 and 5.61, respectively, at pH values below the PZC, the sample surface becomes protonated and exhibits a positive net charge on the surface (Equation (8)), whereas at pH above pH PZC , surfaces are negatively charged (Equation (9)).…”

Comparison of Fenton and Photo-Fenton Processes for Removal of Linear Alkyle Benzene Sulfonate (Las) from Aqueous Solutions

“…The removal efficiency of surfactants from aqueous environments depends on the method of treatment employed [18]. Various procedures are employed for removing or destroying surfactants, including an anaerobic fluidized bed reactor (FBR) [19], chemical or electro-chemical oxidation, membrane technology, chemical precipitation, and photo catalytic degradation [6,17,[20][21][22]. However, the limitations of biological procedures and difficulties in using other technologies (such as membranes) or adsorbing procedures challenge us to develop and employ new methodologies to deal with this issue [5].…”